WEBVTT

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Alright, good afternoon everybody. Happy Tuesday. Thank you so much for being here with us today. Before we get started, we're just gonna cover some quick housekeeping rules, regarding this training.

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So this training is being recorded and it will be offered on demand through Clue in for those who are not able to join us live.

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The Clue and Training page offers the slides as well for you to download. Under the tab that says download training materials.

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You can use the QA box at any point during this training to ask questions, make comments or report any technical problems at any time.

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We will have a question. Answer break about halfway through the training as well as at the end of today's modules.

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Please note that time will likely limit us and we expect to not answer all of the questions that are submitted today.

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As well as legal slush regulatory interpretation questions. For those of you that are interested in receiving certificates of completion, those will be available, at the end of our training today upon completion of the feedback form.

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Once you complete the form and click the box to certify that you participated, that certificate will be provided to you.

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Today's training is sponsored by the Interstate Technology and Regulatory Council or the ITRC and is hosted by the US EPA Clean Up Information Network, also known as

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The Interstate Technology and Regulatory Council is a program of the Environmental Council of the States.

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ITRC is a state-led organization composed of over 1,000 members from state agencies, federal government, the private sector, academia, and community stakeholders.

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Hi, TRC is partially funded by the US government and ITRC nor the US government warranty the material nor endorse any specific products.

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So on behalf of the Interstate Technology and Regulatory Council, welcome to today's training, PFAS, Beyond the Basics, Human Health, Ecological Effects and Regulations Training, which is based upon the .

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My name is Sarah Levy and I will be your moderator for today. I'm now going to turn it over to Christy.

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I'm now going to turn it over to Christy. I'm now going to turn it over to Christy Herzer with the Vermont Department of Environmental Conservation, who is one of the state team leaders for the ITRCP FAST team.

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Chris is going to introduce us to today's trainers. So welcome Christie.

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Thank you. Sarah. As Sarah mentioned, we're very excited to bring you ITRCs second offering in our new series, P Fast Beyond the Basics.

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And we will be going more in depth than our introduction to PFAS training. So we do expect that participants have an introductory level understanding of PFAS.

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Because we will be diving more into the technical details of these topics and in our introductory PFAS training.

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So I'm very excited to partner with the trainers today to bring you this new Beyond the Basics PFAS training.

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Today's trainers are Linda Hall, Lisa Mcintosh, and Bree Sterling.

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We've all worked together on ITRCP FAST team for many years and the different perspectives and expertise that will be shared with you today will help you advance your understanding of PFAS, human health effects, ecological toxicology, risk assessment, and regulations.

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We encourage you to take a look at our consensus driven free technical resources. They can all be found on our website listed here.

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You can find our technical and regulatory guidance document. We affectionately call it tech reg for short. The latest version is from September of 2023.

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The training today is based on the tech reg from September of 2,023. We also have 13 fact sheets which were updated to remain current with the tech reg.

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We also have a number of external tables and information that you can download and access quickly such as our soil and.

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Water values table which is updated approximately quarterly. As a reminder, today's training is beyond the basics.

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But if you do need a refresher or perhaps a colleague wants to watch our introduction to PFAS training.

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It is archived on the Clue in website listed here. Like Sarah mentioned today's training along with our other beyond the basics trainings will be archived on the Clue and website as well.

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And then finally, on our website, we do have a variety of shorter and medium length training modules, including our roundtable discussions.

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So as I've mentioned, this is our second in our new offering of Beyond the Basics series.

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Last week was our 1st training in the series. And, Today, April 23, rd you're attending human health effects, ecological toxicology, risk assessment and regulations.

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Registration is now open for our May 9th training, which will cover biosolids, leaching, mobility, and aqueous film forming phones.

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And then on May 23rd we have source identification. It's like, and transport and then we'll wrap up the series on June 13th with treatment technologies.

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Again, these modules are going to be recorded and archived for later viewing.

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Now love to turn it over to Linda to kick kick off the technical content starting off with human health effects.

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Hello, Linda.

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Hello, Christy, thank you. Alright, so good morning or good afternoon depending on where you are joining this training from.

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In this presentation i'm going to be talking about information on the potential human health effects of PFAS.

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As Christy indicated, the content of this presentation is based on the tech rank document specifically. Exception 7 1 and 17.2.

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I will note that my particular presentation does not address human health risk assessment or site risk assessment of PFAS.

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That information is available, however, in the tech rig document in sections 9 1 and 17.3.

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In developing these slides, we did target them to an audience that has some technical knowledge of the potential toxicity of PFAS, but who is also interested in taking their knowledge beyond the basics.

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And so we very much hope that this presentation beats those expectations.

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Alright, Sarah, I'm going to need you to step in in advance slides. Thank you.

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So our previous training addressed the potential health effects of per floral alkyl acids, PFAs.

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As well as Gen X and Adonna. In this presentation, I'm going to expand on what we know about the toxicology.

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Of those groups, but also talk about ether and poly ether carboxylates, ether and poly ether sulfonates.

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Fluoratomic alcohols and sulfonates. I will also talk about the recent use of epidemiology data.

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Of data from epidemiology. Studies to develop toxicity factors and guidelines. And on a related note, the EPA has recently used a mixtures assessment or hazard index approach to develop an MCL for the combined concentration of 4 PFAS by MCL.

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I mean maximum contaminant level. And I'm going to, review some of the different ways of assessing the potential for adverse effects when exposed to PFAS mixtures.

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Also going to note and talk a little bit about the fact that certain agencies are regulating PFAS class.

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I'll explain why some support this approach. And also give some examples of where it's been used.

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We'll spend a little bit of time talking about PFAS inhalation, exposure, and toxicity, particularly how chemical and physical properties are important, or especially important to this exposure pathway, and then end with a brief overview of what we currently know about the dermal absorption of PFAS.

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Next slide, please.

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Okay, so if humans are exposed to per flora alkyl acids, these PFA is.

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And by this I mean substances like PFOS, PF and A, Those PFAs partition primarily to protein, not to fat or to lipid.

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And what that means is that traditional models. That have been used to predict the persistence. In the bio accumulation of other environmental contaminants are not useful in understanding PFA behavior within the human body.

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It also means that PFA A's have been measured when they have been measured in humans. The highest levels have been found in the blood, in the liver, the kidney and in muscle tissue.

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PFAAs are not metabolized. I indeed they are terminally stable in humans and a non human species as well.

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Certain PFA is known as polyflora alkyl chemicals are referred to, however, as precursors because they may in fact be metabolized.

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I thought metabolism does occur, however, the end product of that metabolism. Our metabolites that are these terminally stable per flora alkyls that do not undergo further degradation.

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In humans, PFAs are reabsorbed from the kidney with very slow elimination in urine.

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And it is in fact this phenomenon of reabsorption that underlies their persistence in the human body.

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With long chain PFAs persisting in humans for one to several or more years. The last point I'll make here about the biological fate is that slower elimination that is a longer half life of the long chain PFAs results in higher levels in the body of these chemicals than we see from the same dose of short chain.

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Next slide, please

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Okay, to provide the context to understand the address of the PFAS that I'm going to talk about today.

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It's important to look at what we know about the adverse effects of PFAS in general. Based in studies and laboratory animals.

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So the key points of this slide and actually of the next several slides. Are that 1st and foremost the extent of mammalian toxicity data varies widely across different groups of PFAS.

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Toxic logic effects of the PFAS that we have seen in laboratory animal studies are generally similar.

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But it's also true that the toxicologic potency of different PFS varies widely.

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I saw the return to my 1st point, the extent and availability of toxicity data does indeed vary widely across groups of PFAS with data really only for a few PFASs that include PFA, a PFOS, PFA, and a few others.

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ITRC has identified or is at least aware of some mammalian animal data for about 20 p fast, most of which are the per fluoro alkyl acids that I've previously talked about.

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We have no mammalian animal data for the vast majority of PFAS. Of the PFAS that have been studied only for have been studied with regards to their carcinogenic potential in animals.

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And of those 4, 3 were positive, PFOSS, and Gen X. However, was negative

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What we do see from laboratory animal studies, however, is that the toxicologic effects of those PFASs that have been studied are generally similar with all PFAS tested to date eliciting some degree of liver toxicity.

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And as you'll see on the next few slides, many PFAS also have caused developmental, reproductive, immune, hematologic, and thyroid effects in animals.

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Lastly, for this slide, the toxic logic potency of different PFAS does in fact vary widely.

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And when I use the term potency, I mean the dose at which effects occur. In general long chain PFAS are more potent.

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Then short chain PFAS and a primary reason is the higher levels in the body that we see for launching PFAS.

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Then for sure chain P fast when the same dose is administering. Next slide, please. Okay.

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So there is a lot of information on this. This slide and. But it's important for all of you to see it in one place to help you understand.

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The fact that the PFAS steady to date generally have been found to cause similar types of toxicity in experimental animals, I mean mice, rats, and in some cases monkeys.

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I mentioned. Differences in toxic logic potency and in looking at this slide it is important that you remember or keep in mind that the doses at which PFAS have caused these different effects that we've tabulated here.

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Can in fact be very different. And so this particular slide compares the types of effects that have been studied.

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Or observed for different PFAS, but it does not tell you anything does not give any information whatsoever on the relationship between deaths and response.

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So the colors used for the PFAS names distinguish between the short chain PFAS, which are shown in green, in the long chain PFAS, which is shown in blue.

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I will note again that, only 4 of these PFASs have been studied for carcinogenicity, a tabulated as tumors in the right-hand column.

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I do single out the results for PFHXA as being negative there just to call attention to that particular compound in that particular finding.

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Next slide.

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Okay, so the bottom 3rd of this table. Summarizes information on these additional PFAS that we are addressing today.

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The Ether and Poly Ether carboxylates, the fluorotelimar alcohols and sulfonates, and the ether and poly ether sulfonates.

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Next slide, please.

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So in this, this slide, I show that all of the PFAS in this table, including the 3 noon groups.

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Currently under discussion, cause liver toxicity. The one exception, is for one of the short chain Pfaas PFPE a, it's a 5.

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Carbon PFAS. There are simply no studies of liver toxicity in mammals that we have identified.

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All of the other PFAS listed in this table have cost effects on the liver. Next slide.

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So all per fluoro alkyl carboxylates and all peripheral alkyl sulfenates listed in this table that have been tested as well as certain ether and poly ether carboxylates and fluorotelomer alcohols have caused developmental and or reproductive toxicity.

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These effects are often related to growth and development. Such as decreased fetal or neonatal body weight and delayed time to reach developmental markers such as Okay.

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PFAS are not typically associated with teratogenic effects. That is, they are not known to cause developmental malformations.

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Next slide, please.

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Right. So one of the very substantial changes in the use of PFAS health effects data in recent years.

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Is that PFAS, epidemiology studies and cancer rather than non cancer effects are increasingly being used as the basis of toxicity factors and drinking water guidelines.

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Previously, non cancer effects in animal studies had provided the basis for all PFAS toxicity factors and drinking water guidelines.

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But human data for non-cancer effects, especially immune system effects. And cancer in humans or cancer in laboratory animal.

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Data are being factored into the development of a number of toxicity factors and their drinking water guidelines. And one of the really significant results of changing to the use of human data and or cancer risk is that in general.

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Both the toxicity factors and the associated drinking water criteria. Our substantially more stringent than when they were based on animal data.

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Next slide.

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Okay, so the EPA has developed a number of toxicity assessments for different PFAS, as we've summarized in this slide.

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And what we've done here is contrast those toxicity values developed from animal studies shown in black font.

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With those derived from human or epidemiologic studies, which are shown in blue font.

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And for the non cancer reference doses, which you see in the left hand column, the second one from the left.

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What you'll see by comparing the animal and the human values is that the values based on human data are substantially more stringent than those that were based.

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I'm sorry, I think I said that wrong. The values that are based on human data are substantially more stringent than that's based on animal data.

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Next slide.

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So if we take a closer look at some of the epidemiologic data that have been used recently to develop toxicity factors.

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We see, for example, in the case of the European Food Safety Authority or FSA that they identified a tolerable weekly intake for a total of 4 different PFAS, PFA, PFASS, PF, NA and PF HXS.

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That, intolerable weekly intake is based on the level of maternal exposure.

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To these 4 PFAS deemed to be protective. Against a decreased vaccine response in breastfeed children.

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If you look at the right hand side of the slide, the primary basis of the OCP is very recent maximum contaminant level 4 p 4.

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Is an increase in kidney cancer in the general population. But the USCPA also developed a supporting reference dose that is for non-cancer effects.

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Oh, for the MCL, 4 p 4. And that RFD was selected to be protective against a decreased vaccine response in children.

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An increase in low birth weight beginning humans in an increase in cholesterol again in humans. For P FOSS are the primary basis of the recently promulgated MCL is liver tmers and rats.

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Now I don't show that on the slide because we're talking about human health effects. But the supporting RFD for PFOS that the EPA, derived is based on an increase in low birth weight and an increase in tuba cholesterol, again, using human data.

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Next slide.

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This state of California. Also just recently finalized their public health goals or PhDs. 4 PFOS.

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These were finalized just a week or 2, I believe, before the EPA on CLs.

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California's, PHG for PFO is based on kidney cancer in humans.

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In the PhD for PFAS is based on rat liver tumors. California EPA also developed health protective concentrations, which are higher than the cancer based PhDs.

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These were in fact based on non cancer effects. 4 p 4 they utilized or relied on human data for increased alanine transaminase or ALT that's a liver enzyme indicative of liver damage.

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And for P they relied on data human data related to increased cholesterol. Look at the right hand side of this slide in draft US EPA.

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Pardon me, Iris or integrated risk is information system assessments. The agency identified a decreased vaccine response in children for both PFHS and PFDA as well as a decrease in birth weight for PFDA, NPF.

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Next slide, please

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So the state of Minnesota. Early in 2,024, a promulgated drinking water guidelines for PFOS that were in fact the 1st US values to be finalized.

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That were in fact the 1st US values to be finalized that were based on human data or cancer risk where the cancer risk pertained either to human or to animal.

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And then these were followed by the Cali PHGs that I just mentioned and I think we probably all know about the EPA.

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Jeez. That we're finalized just a week or so ago. Next slide, please.

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Okay, turning our attention to assessing the toxicity of PFAS mixtures. So the science of mixtures assessment is important to interpreting the potential toxicity of PFS.

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Because human exposure is rarely if in fact ever to a single PFAS. And the reason for that is PFAS are ubiquitous in the environment and they are present as mixtures in soil, in water, in air, and in consumer products.

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And when exposure is to a mixture and this statement actually holds true not only for P fast but for other chemicals as well.

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The effects can be additive. That is one plus one equals 2 or they may be synergistic more than additive or in fact they may be antagonistic, meaning less than additive.

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Next slide, please.

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So how the effects of mixtures are assessed. It depends on whether we have data from laboratory studies and whether those studies are of defined mixtures, where we have known concentrations or undefined mixtures, something like a complex mixture of known and unidentified PFAS such as we might find in aqueous film forming film where A triple F.

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The other important consideration is whether we're conducting a risk assessment, for example, of environmental mixtures, in which case we typically need to make assumptions about those how those mixture components may interact.

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Next slide, please.

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To study mixtures, toxicology in the laboratory, there are several different types of animal models that have been used.

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These include or cell cultures. Zebrafish, a model species of fish that is used to study mammalian toxicity.

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And of course, mammals most typically m mice and rats.

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Each one of these different model systems supports the study of different endpoints as I've listed in this slide.

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But all of them share the fact that there are very few studies of available of any type. And given the highly variable types of PFAS mixtures that are found in the human environment, it's really challenging.

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Laboratory studies. That reflect. I guess I would say typical human exposure because that human exposure is likely so variable.

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Next slide, please.

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In human health risk assessment, there are several different ways to assess the potential effects of a PFAS mixture.

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One of the most commonly used approaches is the total and concentration approach, which is also known as simple addictivity.

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And in this approach, it is assumed that the toxicity as well as the potency of all of the key cells that are that this is being applied to.

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Are identical. Again, it assumes that the toxicity and the potency are identical if they included PFS.

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So several states do in fact use this approach and apply it to mixtures of 5 or 6 long chain PFAs.

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Ultimately, one can calculate a hazard index or HI. Where that is the sum of the ratios of the dose of each PFAS to that reference dose.

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And this is interpreted. As if HI exceeds one, it is generally interpreted to mean that there may be adverse effects if that level of exposure occurs.

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The hazard index approach also assumes additivity of toxicity, but unlike the total concentration approach, assumes that each PFAS differs in potency.

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And this hazard index approach can be used for non cancer reference doses with the same or different endpoints, meaning liver and thyroid effects can be considered.

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Together and it is in fact the method used by the USCPA, for their drinking water MCL for PFBS, PF, HXS, PFN, and Gen X.

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Next slide, please. So this slide expands on my last point, which is that the EPA used this hazard index approach.

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For its recent MC off before the 4 PFAS we've listed here. The critical effect, that is the most sensitive effect known to be caused by each of these PFAS.

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Varies with adverse effects on the thyroid identified as the critical effect for PFH excess and PFBS.

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But the liver, liver effects were identified, for Gen X. And for PFN, it was developmental effects.

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This table also shows in the middle column the health based water concentration, which is the level at which no health effects are expected for that particular PFAS.

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And the EPA interprets this MCL to mean that it is in fact exceeded if a hazard index is greater than one.

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But not all 4 PFAS need to be present to exceed the hazard index. And in fact, it is possible to exceed the hazard index if 2 or more of those health based water concentrations are exceeded.

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Next slide.

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The relative potency factor approach or toxicity equivalency factor approach is yet another method used to assess the adverse effects of mixtures.

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To apply this to PFAS, it's a little bit different than the 2 other approaches I've talked about.

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One begins by identifying an index compound, for example, PFO, and assigning that index compound a relative potency factor or RPF of one for a given endpoint.

00:29:45.000 --> 00:29:55.000
And then other PFAS are assigned different potencies for that same endpoint based on the strength or the relative strength of their effect.

00:29:55.000 --> 00:30:02.000
This approach also assumes dose additivity, but it makes that assumption only for the selected end point.

00:30:02.000 --> 00:30:15.000
And if any of you are interested in looking, further into this particular approach. A group of Dutch scientists have applied the RPF approach to a group of 22 PFASs using liver effects as the end point.

00:30:15.000 --> 00:30:25.000
I give the citation here its bill at all, 2,021. If you're interested in tracking that down.

00:30:25.000 --> 00:30:33.000
The RPF approach has in fact been used for dioxins and for other chemicals whose mode of action is known.

00:30:33.000 --> 00:30:52.000
And furthermore, when that mode of action is known to be relevant for the end point in question. But it's substantially more complicated for PFAS, however, in that there are likely multiple modes of action and those modes of action may in fact differ on the end point as well as on the PFAS.

00:30:52.000 --> 00:30:56.000
Next slide, please.

00:30:56.000 --> 00:31:08.000
Great, turning to the question of addressing TFAS as a class. I'll begin by noting by explaining that the reason this issue has been raised for PFAS is that there are so many PFASs that have been identified approximately 12,000 or more at this point in time.

00:31:08.000 --> 00:31:26.000
That our usual paradigm of chemical by chemical regulation is not simply feasible for every PFAS of interest.

00:31:26.000 --> 00:31:31.000
So, normally when chemical is regulated, it is typically regulated only after years of study to understand how it may affect different systems within our bodies.

00:31:31.000 --> 00:31:42.000
Whether it's genotoxic, whether it's carcinogenic, a reproductive toxicon, and so on.

00:31:42.000 --> 00:31:55.000
And many of those studies take years to conduct and it's 1 of the reasons that we that I have said that only about 20 PFAS are truly well-studied toxicologically.

00:31:55.000 --> 00:32:05.000
And so to address this concern about the lack of regulation for a majority of PFAS. Some have proposed to group.

00:32:05.000 --> 00:32:15.000
And to regulate pea facet based. On intrinsic properties such as persistence toxicity structure or other characteristics.

00:32:15.000 --> 00:32:28.000
And others have proposed to group PFAS to inform risk assessment based on assumptions of additive toxicity, relative potency factors, a mode of action, and others.

00:32:28.000 --> 00:32:33.000
Next slide, please.

00:32:33.000 --> 00:32:44.000
So some agencies have in fact regulated PFAS as a class and I'm just showing a couple of examples here including a proposed action of the European Commission.

00:32:44.000 --> 00:32:47.000
And a couple of actions by california's DTSC or Department of Toxic Substances Control.

00:32:47.000 --> 00:33:01.000
These regulatory actions that have treated PFAS as a class have generally been related. To the use of PFAS in products.

00:33:01.000 --> 00:33:12.000
Regulation of Pefasas class has not been used as the basis for PFAS guidelines for drinking water or other environmental media.

00:33:12.000 --> 00:33:16.000
Right, next slide, please.

00:33:16.000 --> 00:33:36.000
Okay, so one of one of our last topics this morning is inhalation exposure and toxicity of us and I've divided my comments into those that address negatively charged PFAS in this slide and neutral PFAS, which are covered in my next slide.

00:33:36.000 --> 00:33:45.000
Negatively charged PFAS. Examples would include a number of the peripheral alkyl acid such as PFO and PFOS.

00:33:45.000 --> 00:33:53.000
And per fluoro alkyl ether carboxylates such as the gen x compounds.

00:33:53.000 --> 00:34:07.000
These substances are generally not volatile. And so for these negatively charged PFAS, a major source of inhalation exposure is dust from the degradation of treated consumer products.

00:34:07.000 --> 00:34:19.000
Worker exposure is thought to be primarily worker inhalation exposure is thought to be primarily to PFAS aerosols bound to dust in the workplace.

00:34:19.000 --> 00:34:26.000
There is very, very limited inhalation toxicity data, at least to date, for PFOA.

00:34:26.000 --> 00:34:33.000
We have a few studies. For PF and A and genetics. We have one study for each.

00:34:33.000 --> 00:34:45.000
And to the best of my knowledge for all of the other PFAS, we simply have no other inhalation data for negatively charged PFAS compounds.

00:34:45.000 --> 00:34:58.000
With the limited studies that are available to us, the toxic effects following inhalation exposure do in fact appear to be similar to those seen from oral exposure.

00:34:58.000 --> 00:35:08.000
And, relying on this fact, some states have developed inhalation guidelines that are based on route to route extrapolation.

00:35:08.000 --> 00:35:11.000
Next slide please.

00:35:11.000 --> 00:35:14.000
Hmm. So neutral, tend to be volatile compared to negatively charged PFAS.

00:35:14.000 --> 00:35:27.000
So me examples of the neutral PFAS include certain flora telomere alcohols and per fluorinated sulfonamids.

00:35:27.000 --> 00:35:43.000
Because of their volatility. Inhalation of vapors in indoor air may in fact be the primary exposure route for individuals in residences and potentially in public and commercial buildings.

00:35:43.000 --> 00:35:51.000
Once again, there are no inhalation toxicity studies of PFAS in indoor air, at least to date.

00:35:51.000 --> 00:36:04.000
But we do, expect that absorption and metabolism, if it occurs, would be similar for both inhalation and oral exposure routes, again based on the limited toxicity studies.

00:36:04.000 --> 00:36:08.000
That we have for the negatively charged PFAS.

00:36:08.000 --> 00:36:12.000
Next slide.

00:36:12.000 --> 00:36:27.000
Okay, so our final topic is the dermal absorption of PFAS and it's a topic where we have really limited information on the absorption or the toxicity of PFAS following dermal exposure.

00:36:27.000 --> 00:36:37.000
We do have some recent roadent data, where dermal absorption of per fluorocarboxylic acids per floral.

00:36:37.000 --> 00:36:46.000
Alkyl sulfonates and diabs have in fact been shown to be dermally absorbed.

00:36:46.000 --> 00:36:52.000
The extent of absorption not surprisingly varied with the compound and the dose in the rat study.

00:36:52.000 --> 00:36:59.000
And in a study with mice we have toxicity in gene expression changes where in fact observed in the liver and scan.

00:36:59.000 --> 00:37:15.000
Of the study, study animals. We have a very little bit of recent human data in which PFO up next to a sunscreen was in fact absorbed through human skin.

00:37:15.000 --> 00:37:26.000
But our current evidence overall is that dermal absorption of PFAS from soils or water are not expected to be an important exposure route for general.

00:37:26.000 --> 00:37:30.000
General public. We get a lot of questions. There's a lot of interest on the dermal absorption of PFAS.

00:37:30.000 --> 00:37:45.000
So this is indeed a topic of very high interest and I expect that we will see additional publications on this in the not too distant future.

00:37:45.000 --> 00:37:53.000
Next slide, please. Okay, so in closing, I'll just note that as with all things PFAS, the knowledge of the potential human health effects of PFAS is changing very quickly.

00:37:53.000 --> 00:38:23.000
And the information in the technical regulatory document is best viewed as a snapshot in time. For example, since our latest revision to the tech great document, which was in September of last year, the International Agency for Research on Cancer or IARC, updated its classification of the carcinogenicity of Pefoa from group 2 B, which means possibly carcinogenic to humans according

00:38:25.000 --> 00:38:35.000
to IRC. They updated it to be group one, which is defined as being carcinogenic to humans, again using IRCs criteria.

00:38:35.000 --> 00:38:45.000
PFOS, was classified by IRC for the 1st time as a group to be possibly carcinogenic to humans.

00:38:45.000 --> 00:39:06.000
This month as I've mentioned and I'm sure most of you are aware that EPA finalized national primary drinking water standards or MCLs for PFOSS, PFOSS, PFOSS, PFHS, PFA, and genetics chemicals, as well as the hazard index based MCL for PFH access, GPS and

00:39:06.000 --> 00:39:16.000
PFPS. And so we know that there will be other changes to our knowledge of PFAS toxicology that develop in the coming years.

00:39:16.000 --> 00:39:27.000
The direction of how that knowledge is going to change is really, really unknown. We will be considering and potentially addressing some of these.

00:39:27.000 --> 00:39:35.000
Technical issues under what we're referring to as priority topics, in our work, our ongoing work.

00:39:35.000 --> 00:39:47.000
For ITRC. For example, our priority topics may in fact include addressing epidemiology studies of a population of this exposed to A triple F and drinking water.

00:39:47.000 --> 00:40:09.000
We've we are considering expanding our discussion on the inhalation of PFAS. Or of dermal exposure and toxicity depending on the availability of information and of course also addressing adverse effects of additional PFAS as that information becomes a bill.

00:40:09.000 --> 00:40:22.000
And I believe that that ends my presentation. Next slide and we'll, I'll take a couple of questions if time, per minutes.

00:40:22.000 --> 00:40:28.000
Yes, thank you so much. Linda for your portion of today's training for your presentation.

00:40:28.000 --> 00:40:39.000
We will now move into our 1st of 2. Qa pods. So our QA session.

00:40:39.000 --> 00:40:49.000
So at this time, our attendees can type their questions into the QA pod in the bottom right corner of their screens.

00:40:49.000 --> 00:40:50.000
Hmm.

00:40:50.000 --> 00:41:04.000
And we're going to try to get through as many questions as we can. And just as a general reminder, our trainers are not able to respond to questions that ask about states or EPA actions as well as legal slash regulatory interpretation questions.

00:41:04.000 --> 00:41:08.000
So with that being said, Linda, we do have several questions. For you. So we're just gonna dive right into it with our 1st question.

00:41:08.000 --> 00:41:14.000
You mentioned that the PFAs are absorbed in the human body, but not metabolized.

00:41:14.000 --> 00:41:29.000
Can you describe again the biological fate of the Poly fluoro alkal substances, the precursors in humans.

00:41:29.000 --> 00:41:39.000
I'm sure so. We do not it's important to recognize that we do not have human data on the potential metabolic transformation of polyfluoro alkyl substances in humans.

00:41:39.000 --> 00:41:54.000
What we do have is data from certain animal studies. Which do indicate, that polyflora alkyls.

00:41:54.000 --> 00:42:02.000
May be metabolized in vivo to these terminally stable per flower alkyls.

00:42:02.000 --> 00:42:16.000
If such metabolism does occur occur in humans, we don't yet know the rate of transformation or the relative importance of different metabolic pathways.

00:42:16.000 --> 00:42:29.000
And by that I mean the animal data that we do have available to us. Shows some fairly complicated metabolic transformation pathways that occur in rodents.

00:42:29.000 --> 00:42:39.000
And so again, we don't know if these same metabolic transformations occur in humans and if they do the relative importance of any of them.

00:42:39.000 --> 00:42:40.000
Thank you.

00:42:40.000 --> 00:42:44.000
Yeah, thank you so much for addressing that. We're just gonna continue to move through.

00:42:44.000 --> 00:43:01.000
Our questions. So the next question we have for you is why our recent long chain PFAS toxicity factors and drinking water guidelines based on human data and why we're older ones based on animal data.

00:43:01.000 --> 00:43:12.000
Yeah. You know, the US EPA, and state agencies and, other regulatory agencies that I'm aware of.

00:43:12.000 --> 00:43:22.000
I generally have guidance that supports the use of human data as the preferred basis for toxicity data. When appropriate data are in fact available.

00:43:22.000 --> 00:43:30.000
And given the. Really increased scrutiny of PFAS over the last number of years.

00:43:30.000 --> 00:43:42.000
We've seen a large number of epidemiology studies. I'll become available particularly of the long chain PFAS and they've looked at various health endpoints.

00:43:42.000 --> 00:44:03.000
When those data have been published and reviewed and found to be appropriate. The USCPA and states as well as I said, EFSA in one of my slides have in fact concluded that these data are sufficient to use as the basis for toxicity factors for these different PFAS.

00:44:03.000 --> 00:44:18.000
And again, all of those agencies have a policy have a preference. Of relying on human data as opposed to animal data when high quality data are in fact available.

00:44:18.000 --> 00:44:25.000
Those high quality data have become available in the last few years. And I'm now being relied on.

00:44:25.000 --> 00:44:41.000
Excellent, thank you so much. It looks like the next question we have for you, asks, why are the toxicity factors based on human data much lower than the earlier ones based on animal data.

00:44:41.000 --> 00:44:54.000
Sure. So The human, most of the human studies that have been used as the basis for Toxicity factors.

00:44:54.000 --> 00:45:04.000
For the long term PFAS in particular were conducted in the general population as distinct from an occupational or worker population.

00:45:04.000 --> 00:45:17.000
And the blood serum p fast concentrations. At which dose related effects have been observed in these human or epidemiologic studies.

00:45:17.000 --> 00:45:25.000
Are simply far below the blood serum feet PFAS levels at which effects have been observed in laboratory animals.

00:45:25.000 --> 00:45:35.000
And so they lead to correspondingly more student criteria as a result.

00:45:35.000 --> 00:45:43.000
Excellent. Thank you again. Moving into our next question. Looks like we have time for maybe one or 2 more.

00:45:43.000 --> 00:45:51.000
Okay.

00:45:51.000 --> 00:45:52.000
Hmm.

00:45:52.000 --> 00:45:54.000
Can you explain the separate MCLs for PFOS as opposed to including them in the hazard index with the other 4

00:45:54.000 --> 00:46:06.000
Sure. And this is, you know, relying, this is not my interpretation. This is, of course, relying on information the EPA has publicly provided.

00:46:06.000 --> 00:46:15.000
But the MCLs for PFO and PFOS are each based on the practical quantization limit or the limit of detection.

00:46:15.000 --> 00:46:43.000
And that level is 4.0 nanograms per liter. And the EPA. The MCL at the LOD lots of acronyms here because the health based goal is so so much lower than that that it was not feasible for a majority of a commercial analytical laboratories to quantify it.

00:46:43.000 --> 00:46:57.000
So as the EPA explained has explained, the lowest. Concentration of PFO or PFOS that can be measured for regulatory purposes is this 4.0 nanograms per Thank you.

00:46:57.000 --> 00:47:07.000
And a detection at this level or above. Of one of these compounds. Even without detection of any of the other PFAS would in fact result in exceeds of the hazard index.

00:47:07.000 --> 00:47:22.000
Of one, again, because the health base concentration that's in the denominator of that hazard index is so much lower than the 4 parts per trillion or the 4 nanograms per liter.

00:47:22.000 --> 00:47:28.000
And so it wouldn't be appropriate or meaningful. To include P or PFOS in this combined MCL based on the hazard index.

00:47:28.000 --> 00:47:45.000
Because their mere detection would trigger and exceed each and every time. And so the EPA sought to regulate them individually.

00:47:45.000 --> 00:47:52.000
Alright, well, thank you so much, Linda, for, your presentation and for, answering some of those questions for us.

00:47:52.000 --> 00:48:05.000
We really appreciate it. We are going to move on, but we will have one more opportunity to answer more questions at the end of the class today.

00:48:05.000 --> 00:48:06.000
That all of our attendees can use the Q&A pod at any time during the training to ask questions.

00:48:06.000 --> 00:48:14.000
Our trainers are monitoring it during the presentations. For the questions that get put in there.

00:48:14.000 --> 00:48:31.000
But with that being said, I'm now going to turn it over to Lisa Mcintosh to discuss ecological toxicity and risk assessment with us.

00:48:31.000 --> 00:48:35.000
Thanks, Sarah.

00:48:35.000 --> 00:48:46.000
I don't know if you Oh, there I see it. Okay. All right, so we're going to switch gears from human health to echological toxicity.

00:48:46.000 --> 00:48:56.000
I'll give you a brief overview of ecological exposure. So how, organisms or ecological receptors are exposed to P fast.

00:48:56.000 --> 00:49:02.000
We'll go over some key concepts that are a little bit unique to eco toxicology versus human health.

00:49:02.000 --> 00:49:10.000
We'll talk a little bit about the various toxicity studies that have been done for different tax or different groups of organisms.

00:49:10.000 --> 00:49:21.000
And talk about PFAS with respect to ecological risk assessment. And throughout the talk, I'll be bringing in some uncertainties or data gaps that currently exist.

00:49:21.000 --> 00:49:28.000
So I'm not seeing my little advance button. But.

00:49:28.000 --> 00:49:38.000
Yeah, okay. So I wanted to refer you back to the PFAS guidance document. There are a few different sections that are relevant to ecological toxicity.

00:49:38.000 --> 00:49:53.000
So section 7.2 is. A section on ecological toxicity and that provides a high level summary of various echo toxicological data that is currently available, as well some of the uncertainties.

00:49:53.000 --> 00:50:06.000
Section 9.2 discusses ecological risk assessment. So how we use that toxicity and exposure information to estimate risk to ecological receptors.

00:50:06.000 --> 00:50:11.000
And I also wanted to refer you back to sections 5.5, 5.6 and 17 3 3.

00:50:11.000 --> 00:50:18.000
And these. Sections talk about PFAS. Accumulation into organisms. So bio accumulation.

00:50:18.000 --> 00:50:27.000
And then throughout this talk, there'll be various references to studies and those could be found in the tech rank document.

00:50:27.000 --> 00:50:38.000
So, start off talking about key transport and exposure pathways for ecological receptors. And so you'll see a diagram in front of you with lots of arrows and boxes.

00:50:38.000 --> 00:50:44.000
And if you're looking through some of the boxes and wondering why don't I have eastern grey kangaroos in my backyard.

00:50:44.000 --> 00:51:01.000
It's because this particular conceptual site model is specific to Australia. So. For this, it's, this diagram showing the pathways that PFAS can get from the environment into different types of ecological receptors.

00:51:01.000 --> 00:51:09.000
So this basically represents a, a food web and a food web is composed at food chains.

00:51:09.000 --> 00:51:17.000
If you go in back to sort of basic biology at the bottom of that food chain, you have the primary producers, the plants.

00:51:17.000 --> 00:51:30.000
That are producing energy, they're consumed by a variety of different types of organisms. Invertebrates are typically at the bottom of the food chain as well, lot of different types of animals eat and vertebrates and plants.

00:51:30.000 --> 00:51:42.000
So you can see the movement of PFAS going from the primary producers and primary consumers. Up through, different types of mammals, birds.

00:51:42.000 --> 00:51:50.000
And so, so on and so forth. So this represents a lot of different complicated pathways for PFAS to move.

00:51:50.000 --> 00:52:07.000
So not only can organisms be exposed through soil or air, they can also be exposed to the diet and the diet becomes really important with respect to understanding ecological toxicity.

00:52:07.000 --> 00:52:14.000
This diagram is the aquatic counterpart to the terrestrial counterpart we were just looking at.

00:52:14.000 --> 00:52:26.000
Aquatic pathways. You know, in general, the pathway approach is similar. We start with primary producers, primary consumers leading up to top predators.

00:52:26.000 --> 00:52:30.000
A little bit of a difference here is that not only do we have surface water and sediment you might need to look at a groundwater to surface water.

00:52:30.000 --> 00:52:46.000
Pathway as well. So again, very complicated, a lot of different ways that PFAS can move through the environment.

00:52:46.000 --> 00:52:56.000
And, with regard to biological uptake of PFAS, there are a few terms that you need to understand to help provide put this information into context.

00:52:56.000 --> 00:53:01.000
So They talk about bio concentration, that's uptake from a single medium and it's typically for water.

00:53:01.000 --> 00:53:11.000
So we might have a bio concentration factor that looks at. You know, how much PFAS would accumulate from into an organism from the surrounding water.

00:53:11.000 --> 00:53:24.000
Bio accumulation accounts for uptake from different sources. So that could be from food, that could be from, sediment, that could be from surface water or soil.

00:53:24.000 --> 00:53:33.000
And then biomagnification is really important with respect to PFAS and that is increasing concentrations of a chemical with trophic level.

00:53:33.000 --> 00:53:40.000
So For example, you might have relatively low concentrations of PFAS and plants or in vertebrates.

00:53:40.000 --> 00:53:53.000
But the consumers of those organisms. So for example, an eagle or a heron eating fish, they tend to have higher concentrations and they get that through the diet.

00:53:53.000 --> 00:54:00.000
And so that's the process called bio magnification that concentration magnifies with increasing trophic level.

00:54:00.000 --> 00:54:09.000
Biological uptake really depends on 3 different factors. So one is structure of the compound.

00:54:09.000 --> 00:54:19.000
The other is the media chemistry so what our chemical conditions like in the surrounding medium And the 3rd is the organism.

00:54:19.000 --> 00:54:28.000
Each organism has its own unique, processes that in physiologies that influence how it accumulates PFAS.

00:54:28.000 --> 00:54:42.000
And so one of the interesting things about TFAS in particular. For animal studies it appears that Generally, the C 7 through C 13 ish.

00:54:42.000 --> 00:54:50.000
P fast compounds in particular ones with cell phone, cell phone groups, tend to be more bioaccumulative.

00:54:50.000 --> 00:55:10.000
Versus plants, which actually have a propensity to uptake the shorter chain P fast and that becomes important when you're trying to understand how KFAS are moving through the environment and how your ecological receptors are exposed.

00:55:10.000 --> 00:55:18.000
So one more mini tutorial. With respect to ecological toxicity. So Linda talked about a bunch of different types of endpoints.

00:55:18.000 --> 00:55:31.000
What the inverse effect or the system that was looked at for some of the animal studies. And human epidemiological studies.

00:55:31.000 --> 00:55:46.000
Ecological toxicity is maybe simplified a bit. We are more focused on what we call ethical endpoints and I've listed 3 here, survival growth and reproduction.

00:55:46.000 --> 00:55:59.000
And so. Instead of looking at things on a molecular level or just even a simple systems level, we're looking at it in observable whole organism outcome.

00:55:59.000 --> 00:56:10.000
As a result of exposure so survival or you know how many die how many survive growth could be measured in different ways reproduction could be measured in different ways.

00:56:10.000 --> 00:56:27.000
These are the endpoints that are unique to ecological toxicity. That help us understand how an ecological, adverse effect could result in an outcome, an adverse outcome to a population.

00:56:27.000 --> 00:56:37.000
So the end game here is to really understand. Is exposure translating to an effect that could affect. A population of an organism.

00:56:37.000 --> 00:56:47.000
And so that's why we focus on these whole whole body type endpoints. They're a little bit more meaningful in terms of looking at groups of organisms populations.

00:56:47.000 --> 00:56:52.000
Information is available. Out there right now for PFAS, there are, many scientific studies available.

00:56:52.000 --> 00:56:55.000
I'd refer you to the USCpa's Eco-tox Knowledge Base.

00:56:55.000 --> 00:57:02.000
The links here. This is a great reference for all the different studies that EPA catalogs.

00:57:02.000 --> 00:57:17.000
They update this, database on a quarterly basis. If you were to just run a simple query for PFAS right now you'd get thousands of records.

00:57:17.000 --> 00:57:23.000
Not all of it is necessarily, specific to every type of PFAS you'd want to know about.

00:57:23.000 --> 00:57:35.000
A lot of that information is specific to PFOS and PFOA, but it is a really good resource as a 1st stop for looking for information.

00:57:35.000 --> 00:57:46.000
Federal and state regulations and advisories. There's good information out there in terms of effect levels that we can start to use to assess risk.

00:57:46.000 --> 00:57:57.000
And then professional organizations have put out some guidance documents as well to help assist us with understanding ecological risk.

00:57:57.000 --> 00:58:04.000
So I am going to launch into a bunch of information about different, different groups of organisms.

00:58:04.000 --> 00:58:20.000
And this, these slides will prevent, will describe a high level summary. So I'd refer you back to the document and to the primary literature if you're interested in understanding, more about any of these groups of organisms.

00:58:20.000 --> 00:58:25.000
So we'll start with aquatic and, or sediment dwelling organisms.

00:58:25.000 --> 00:58:32.000
They could be exposed to P fast via direct contact with their surrounding media, so water, sediment.

00:58:32.000 --> 00:58:42.000
As well so the diet and that includes both through eating other organisms as well as through ingestion of particles such as from cinnamon or soil.

00:58:42.000 --> 00:58:51.000
The focus of the toxicological studies that I'll be discussing has really been historically on PFOS and PFOA.

00:58:51.000 --> 00:59:03.000
And so that my talk is mainly focused on those 2 compounds. For aquatic organisms many of the studies have really focused on freshwater aquatic and acute studies.

00:59:03.000 --> 00:59:19.000
There are very variable results that we see across species, but overall, we see effects occurring on a part per 1 million level for acute exposures and apart per 1 billion to part per 1 million level for chronic exposure.

00:59:19.000 --> 00:59:25.000
So this is, you know, much different from the animal and human epidemiological studies where we're looking at proper trillion levels.

00:59:25.000 --> 00:59:38.000
For cleanup levels. So, you know, very different. But still seeing toxicity occurring, but at higher levels.

00:59:38.000 --> 00:59:45.000
As I said, there's a lot of variability out there. You can have, acute and chronic values overlap.

00:59:45.000 --> 00:59:54.000
Even within a species, you can see, considerable variability. Certain types of species seem a little bit more sensitive than others.

00:59:54.000 --> 01:00:00.000
For example, some of the ordnates like damsel flies or coronavirs.

01:00:00.000 --> 01:00:12.000
They seem particularly sensitive at the low part per 1 million level. And we also see a comparability between toxicity for freshwater and marine species.

01:00:12.000 --> 01:00:20.000
So for bentic studies, there are relatively few studies out there currently. Most of those are on freshwater.

01:00:20.000 --> 01:00:24.000
I reference here a Simpson and L, 2,021 study. This is a fairly comprehensive paper.

01:00:24.000 --> 01:00:44.000
A review paper that, I'm sorry, that is a fairly comprehensive study that looked at a variety of species.

01:00:44.000 --> 01:00:51.000
Organic carbon. Content of sediments. Seems to influence. The toxicity.

01:00:51.000 --> 01:01:04.000
Of PFAS as a result. So that's sort of a novel. Novel paper in the terms of PFAS, eco toxicity for ethnic organisms.

01:01:04.000 --> 01:01:15.000
Again, we're seeing levels toxicity levels and I in what I list here a lethal concentration 50 median lethal concentration of a hundred 50 parts per 1 million.

01:01:15.000 --> 01:01:23.000
And an effect space concentration of 89 parts per 1 million. So again, we're seeing a relatively low toxicity.

01:01:23.000 --> 01:01:28.000
Or PFAS.

01:01:28.000 --> 01:01:35.000
Terrestrial invertebrates. So those are the invertebrates that live on the ground, not in the water.

01:01:35.000 --> 01:01:39.000
They appear to be less sensitive to P fast than their aquatic counterparts. So again, we're still seeing some toxicity on a parts per 1 million level.

01:01:39.000 --> 01:01:51.000
Most of the trustal invertebrate studies to date have been focused on earthworm toxicity.

01:01:51.000 --> 01:02:02.000
So there's a lot of different organisms that live on the ground, a lot of different, bugs and other types of invertebrates that just haven't been tested.

01:02:02.000 --> 01:02:08.000
So we really have very limited information for this group of organisms. But again, there are some studies out there.

01:02:08.000 --> 01:02:17.000
There wasn't interesting study out there, Tom Naga at L, 2,004 and this is discussed in the tech rank document.

01:02:17.000 --> 01:02:31.000
Actually, presented findings from a transgenerational study where they looked, they dose parent worms and then subsequent generations showed some transgenerational effects.

01:02:31.000 --> 01:02:40.000
And again, as we saw with the bentic studies, field conditions, modified toxicity. So things like the type of soil, is it sand?

01:02:40.000 --> 01:02:49.000
Is it loam? The pH of the soil those factors can affect biochemulation and toxicity.

01:02:49.000 --> 01:02:58.000
So as an example, there was a study that looked at. Different types of soil invertebrates.

01:02:58.000 --> 01:03:12.000
And different types of soil. So a sandy loan versus a clean loan and they found that much higher toxicity was associated in the sandy loan versus the clay loan because of the organic carbon content essentially.

01:03:12.000 --> 01:03:13.000
As I mentioned, you know, there are a lot of different species that we don't have data for and we just don't understand.

01:03:13.000 --> 01:03:26.000
You know, what PFAS exposure means for those particular ones.

01:03:26.000 --> 01:03:47.000
So for fish, we have actually a fairly robust data set. A lot of the fish studies today have been focused on acute short-term exposures and again in freshwater but there are other you know, there are adequate data out there and in fact USCPA has developed or have surface water quality criteria.

01:03:47.000 --> 01:04:02.000
Yes. So, again, we see effects on a part per 1 million level for acute, acute exposures and then about a part per 1 billion up to a park per 1 million for chronic exposure.

01:04:02.000 --> 01:04:08.000
So we're, you know, fairly similar to what we're seeing in other types of organisms.

01:04:08.000 --> 01:04:18.000
With regard to the USCPA draft criteria. You can see the acute criteria are several orders of magnitude higher than the chronic.

01:04:18.000 --> 01:04:26.000
Both values are based on species sensitivity distributions that represent up to 5 different types of file.

01:04:26.000 --> 01:04:33.000
And that includes organisms such as different types of fish, shrimp, shelfish.

01:04:33.000 --> 01:04:42.000
Other types of invertebrates, some amphibians. The final values that you're seeing here represent the 5th percentile of that.

01:04:42.000 --> 01:04:52.000
Species sensitivity distribution. So in other words, these values are designed to be protective of 95% of the genera, the EPA evaluated.

01:04:52.000 --> 01:05:01.000
I list here the last bullet here, food chain exposure, might be of greater concern than fish toxicity.

01:05:01.000 --> 01:05:14.000
These EPA draft criteria are developed for direct effects. So, you know, fish exposed to a certain concentration of water.

01:05:14.000 --> 01:05:22.000
But as I mentioned before, certain types of PFAS, especially things like PFOS, they tend to bio magnify.

01:05:22.000 --> 01:05:31.000
So if you have something an organism that consumes fish such as mink that. Water quality criteria.

01:05:31.000 --> 01:05:37.000
That was derived to be protective of fish might not necessarily be protective of organisms that consume fish.

01:05:37.000 --> 01:05:46.000
So that's something to consider.

01:05:46.000 --> 01:05:55.000
Reptiles in amphibians. So currently in the tech rig document, there is no reptile information in section 7.2.

01:05:55.000 --> 01:06:00.000
That is something we are going to be adding as part of the updates. For the next round.

01:06:00.000 --> 01:06:03.000
There's very little reptile information. Out there currently with respect to PFAS, although that is a focus of certain groups.

01:06:03.000 --> 01:06:15.000
The Department of Defense Strategic Environmental Research and Development Group, or SERVA.

01:06:15.000 --> 01:06:25.000
They're looking at reptile toxicity. So more to come on that. So I think we'll focus a little bit more on amphibians today because we actually have a little bit more data on amphibians, mainly frogs studies out there.

01:06:25.000 --> 01:06:44.000
There are some salamander studies as well. Excuse me. Most amphibian data are for PFOS and generally, like I said, there for frogs and toads.

01:06:44.000 --> 01:07:08.000
We see acute effects or mortality, very high end adverse effects at levels of 10 parts per 1 million or higher and chronic effects found at substantially lower concentration several orders of magnitude lower in fact and that indicates a fairly moderate to high toxicity for, amphibians.

01:07:08.000 --> 01:07:14.000
Yes, and to be particularly sensitive during their early life stages. So for example, when they're.

01:07:14.000 --> 01:07:24.000
Some studies of PFOS and frogs have indicated inhibition of growth, delayed time to metamorphosis, formation.

01:07:24.000 --> 01:07:34.000
And these types of effects suggest that PFOS affects the thyroid. So we see some parallels from what Linda presented earlier.

01:07:34.000 --> 01:07:38.000
There's some evidence too that our classic aquatic toxicity studies might be under predicting toxicity that's occurring in the environment.

01:07:38.000 --> 01:07:54.000
So typically within aquatic toxicity study. We, you know, we take a jar of water, spike it with a certain amount of a contaminant and expose an organism to that.

01:07:54.000 --> 01:08:02.000
And that gives us good information on what concentration in the water. Presents a potential risk.

01:08:02.000 --> 01:08:10.000
However, in the wild, organisms are exposed to not only water, but they're exposed to sediment and diet as well.

01:08:10.000 --> 01:08:23.000
One study conducted by Flynn at all in 2021, was a mesicasm study and the mesocosum basically sets up an artificial habitat that has multiple media in it.

01:08:23.000 --> 01:08:33.000
And their findings, suggested that Just by looking at aquatic toxicity alone, you are under estimating toxicity.

01:08:33.000 --> 01:08:41.000
There's also a contribution from other media as well that's not accounted for. P the ladies at L.

01:08:41.000 --> 01:08:48.000
2023 is a great reference. It is a critical review of amphibian toxicology.

01:08:48.000 --> 01:09:02.000
So for those interested in amphibian toxicology, that is definitely a paper you will want to check out.

01:09:02.000 --> 01:09:13.000
And, okay. So for birds. We know that wildlife and in particular birds and mammals are exposed to p fast in the environment.

01:09:13.000 --> 01:09:24.000
There's a wealth of information on PFAS exposure. There's not a lot of information that tells us whether this exposure is meaningful to wildlife populations.

01:09:24.000 --> 01:09:33.000
So with regard to birds, there are really only a handful of baby in studies on PFAS toxicity and those are mostly focused on .

01:09:33.000 --> 01:09:39.000
OS. Exposure. Look, than in quail, few different types of quail and ducts Most of them have been dietary studies.

01:09:39.000 --> 01:09:55.000
Few egg injection studies. And we do see some adverse effects associated with key facets, or in terms of hatching success of eggs, as well as some liver changes.

01:09:55.000 --> 01:10:13.000
And we see a monitor to high toxicity. There been a few maybe in mixture studies, particularly looking at a triple F formations and one study found there might be some additive effects resulting from exposure to multiple types of PFAS.

01:10:13.000 --> 01:10:19.000
But again, you know, while there's some laboratory studies, they're really even fewer field studies on birds.

01:10:19.000 --> 01:10:27.000
And again, going back to that mesicasm study I'd mentioned with amphibians.

01:10:27.000 --> 01:10:34.000
If we're just looking at one particular medium in isolation, that doesn't really tell us the full story.

01:10:34.000 --> 01:10:48.000
So, and one of the big problems with field studies, however, is that it's difficult to ascribe any observed effects to PFAS alone, given the potential for effects to be related to other co contaminants.

01:10:48.000 --> 01:11:01.000
For example, Mercury, LED, PCBs, take your pick. There are a couple of avian studies that have been conducted where PFAS was really the only known contaminant either.

01:11:01.000 --> 01:11:13.000
They're Jason to a place that produce primarily PFAS. And they did not have a background contribution of other types of these legacy contaminants.

01:11:13.000 --> 01:11:24.000
And so for those particular studies, they Haven't found necessarily a strong relationship between p fast exposure and adverse effects.

01:11:24.000 --> 01:11:35.000
So, you know, food for thought, we don't really understand how, is affecting wildlife in the field.

01:11:35.000 --> 01:11:37.000
The, 2,017 is another study referenced in the tech document and they had a different perspective.

01:11:37.000 --> 01:11:50.000
Where they looked at flamingos and PFAS exposure after, a triple app release.

01:11:50.000 --> 01:12:05.000
And they didn't necessarily find. A positive association between PFAS exposure and the birds, reduction in their population, but they postulated.

01:12:05.000 --> 01:12:19.000
What they saw might have been related to actually food supply impact. So in other words, If invertebrates on which the flamingos fed were impacted, the flamingo population, would be impacted by the lack of food.

01:12:19.000 --> 01:12:32.000
So again, we have these other indirect effects that aren't accounted for through, standard toxicological analyses.

01:12:32.000 --> 01:12:39.000
And mammals, Linda already went into a lot of the information. For laboratory data, so I'm focusing more on field studies.

01:12:39.000 --> 01:12:43.000
Again, there's not a lot out there. A lot of laboratory animal studies have been focused on answering what we consider human health questions.

01:12:43.000 --> 01:13:01.000
And again, how is this relevant to populations of animals? Especially with, advances in, Bomics studies and, and, looking at.

01:13:01.000 --> 01:13:11.000
Biochemical markers. We don't really understand if that necessarily translates to a population level effect in the environment.

01:13:11.000 --> 01:13:12.000
So you couple that with field conditions. I can also modify PFAS accumulation and toxicity.

01:13:12.000 --> 01:13:28.000
Some of those we had already talked about like organic carbon content. The existing data set makes it really difficult to correlate field toxicity with the laboratory findings.

01:13:28.000 --> 01:13:38.000
But there are few field based mammalian studies that are referenced in the tech rate document that have found a positive association between concentrations.

01:13:38.000 --> 01:13:52.000
And, different types of endpoints, immunological, humanoidic, renal, hepatic endpoints, so very similar to what we're seeing for some of the laboratory animal studies as well as the human Epis studies.

01:13:52.000 --> 01:14:02.000
And I would be remiss if I did not talk about plants. Plants for plants, apical endpoints are focused on survival and growth.

01:14:02.000 --> 01:14:13.000
So percent emergence, percent survival, shoot height weight, things like that. And oops, sorry about that.

01:14:13.000 --> 01:14:29.000
Get back there. As I mentioned earlier, plants take up short chain PFAS preferentially. Which is interesting because a lot of the PFAS plant studies that have been conducted to date have focused on PFOS.

01:14:29.000 --> 01:14:35.000
And as I showed you in that slide earlier before, PFOS is not one of the PFAC.

01:14:35.000 --> 01:14:45.000
It's taken up preferentially. Again, we say pretty low toxicity for plants with a Q toxicity occurring in the tens to hundreds of parts per 1 million.

01:14:45.000 --> 01:14:58.000
But we also see significant overlap between acute and chronic toxicity as well. For plants, most of the studies to date have been on crop plants, so things like soybean.

01:14:58.000 --> 01:15:24.000
Kale, things like that. And again, we see a very, similar, Similar level of toxicity between aquatic and terrestrial species, but maybe terrestrial a little less sensitive and part of that could be some of the mitigating factors that we see in the environment such as organic carbon content.

01:15:24.000 --> 01:15:32.000
In mixtures. It's pretty complicated. We really at the stage don't have many studies available.

01:15:32.000 --> 01:15:43.000
And I think Linda went into some. Some great detail about. Some of the complications of trying to understand mixture studies and how to look at.

01:15:43.000 --> 01:15:52.000
How, interact with each other. Are there, additive effects or synergies or, antagonistic effects?

01:15:52.000 --> 01:16:00.000
We have a very limiting, limited understanding of the mechanism of action and how all these different compounds work together.

01:16:00.000 --> 01:16:07.000
And again, going back to what we see in a laboratory doesn't necessarily translate to what we see in the field.

01:16:07.000 --> 01:16:15.000
It really just highlights the need for more data.

01:16:15.000 --> 01:16:19.000
So I had talked a little bit about some of the data gaps throughout my slides. I think If you had to boil it down to 3 different topics, it would be representation.

01:16:19.000 --> 01:16:35.000
Of the species. So again, we have out of the universe of species. We have only a very small subset that have had studies conducted on them.

01:16:35.000 --> 01:16:46.000
We've historically focused on PFOS and PFOA, but as you know, there are many, many different types of PFASs and while PFOS tends to show up at.

01:16:46.000 --> 01:16:54.000
At the highest concentrations in many different types of organisms. We just haven't looked for all different PFASs either.

01:16:54.000 --> 01:17:14.000
I mentioned mixtures. I'm trying to understand how mixtures interact. Foams contain the whole next level of potential confounders with in terms of not just toxicity but just sort of physical physical issues with phone.

01:17:14.000 --> 01:17:22.000
And then bio accumulation can vary depending on a whole bunch of different. Factors. So soil.

01:17:22.000 --> 01:17:34.000
Soil or the environmental factors, the type of organism, the type of PFAS that's, organisms are exposed to those who can all affect bioaccumulation.

01:17:34.000 --> 01:17:44.000
So As Linda mentioned earlier, a lot of our models have been based on lipid based. Contaminants, so lipophilic contaminants like PCBs.

01:17:44.000 --> 01:17:51.000
So. We don't have to date great models out there saying, okay, if we are exposed to this, this amount of PFAS, we can predict how much is going to show up in an organism.

01:17:51.000 --> 01:18:05.000
So this really a need to develop these bioaccumulation models that are unique to Yes. And I had touched on ecological relevance earlier several times, I think, at this point.

01:18:05.000 --> 01:18:17.000
So, extrapolating results from individual toxicity studies to population level effects. We really don't have a good understanding of how meaningful some of these.

01:18:17.000 --> 01:18:21.000
Some of these endpoints are in terms of population. And some of the field studies have had sort of contradictory results.

01:18:21.000 --> 01:18:33.000
So some showing effects associated with PFAS and some not showing any effects at all. So.

01:18:33.000 --> 01:18:40.000
Lots of issues out there all stressing the need that we really need to have more data out there.

01:18:40.000 --> 01:18:49.000
So running to shift gears now into ecological risk assessment of PFAS. So we have all this information about toxicity available.

01:18:49.000 --> 01:18:55.000
We know exposure is occurring. How do we put that together and figure out do we have a risk or not?

01:18:55.000 --> 01:19:04.000
Pfas really aren't unique in that respect. So for any given chemical you would follow some kind of protocol.

01:19:04.000 --> 01:19:11.000
We usually start off with screening level, ecological risk assessment or Slera. And that's where you're comparing your medium concentrations to different types of benchmarks tends to be a very conservative screening.

01:19:11.000 --> 01:19:28.000
Basically to screen in. Constituents to see if you have a need to do additional evaluation. And then additional evaluation would be through a baseline ecological risk assessment.

01:19:28.000 --> 01:19:41.000
And that's when you're looking at very site specific information. In different lines of evidence to come up, with a weight of evidence approach as to whether or not your site poses a risk, toological receptors.

01:19:41.000 --> 01:19:52.000
So PFAS follows that same series. That same approach. It's really no different.

01:19:52.000 --> 01:20:01.000
But the difference I think is that, you know, PFAS as a group of chemicals is relatively new for ecological risk assessment.

01:20:01.000 --> 01:20:09.000
Not that P fast or new, but in terms of ecological risk assessment. FASS is relatively new.

01:20:09.000 --> 01:20:18.000
There are now some documents available to help you. Better understand PFA psychological risk assessment and I refer to these.

01:20:18.000 --> 01:20:24.000
These are all mentioned in the PFAST tech rank document. So the Argonne National Laboratory.

01:20:24.000 --> 01:20:33.000
Studies out there that that provide some benchmarks, McCarthy at L and Sodro and L, also great papers.

01:20:33.000 --> 01:20:43.000
To to help you out with that. These levels that are currently available. These, screening levels are available for use.

01:20:43.000 --> 01:20:52.000
Epa has informed their biological technical assistant assistance groups that they they can go ahead and use these levels.

01:20:52.000 --> 01:21:01.000
And I would just stress as I would for any compound. Not just PFAS, at the screening level should not just be used as default cleaning cleanup levels.

01:21:01.000 --> 01:21:09.000
You really need to understand. Site specific conditions as to what that appropriate cleanup level would be.

01:21:09.000 --> 01:21:17.000
Wanna highlight too the science with regard to PFAS. Eco toxicology is constantly evolving and you know, every month new papers are coming out, with different organisms being evaluated.

01:21:17.000 --> 01:21:37.000
Different PPAS being evaluated. So Always good to go back to the scientific literature when you're, assessing PFAS and ecological risk to see what's new out there.

01:21:37.000 --> 01:21:49.000
So I did mention there are some benchmarks available for evaluating ecological risk. I mentioned the EPA draft criteria that are currently out there.

01:21:49.000 --> 01:21:59.000
There's other some states have criteria currently not a whole lot but more and more are developing surface water criteria.

01:21:59.000 --> 01:22:10.000
Again, make sure if you're evaluating that you understand aquatic life. Effects, so direct impacts to aquatic life versus impacts via the food chain.

01:22:10.000 --> 01:22:20.000
Some of those references I had mentioned on the previous slide have these, ecological benchmarks that you can use for screening.

01:22:20.000 --> 01:22:32.000
Also have toxicity reference values. So these are akin to a reference dose that you would use for say human health risk, dose by a particular type of organism.

01:22:32.000 --> 01:22:46.000
In some of the issues with extrapolating from. From one organism to another. Given that PFAS sensitivity can vary considerably based on some of the studies we have now.

01:22:46.000 --> 01:23:05.000
Something to think about is the appropriateness of using a TRV for one species to another. And again, similar to other compounds when we don't have benchmarks or criteria, we for a particular compound, we go into the literature.

01:23:05.000 --> 01:23:11.000
And so for PFAS that do not have any current benchmarks, you would take the same approach.

01:23:11.000 --> 01:23:25.000
Basically go to, the Eco Talks database or do a search, through Google Scholar and see what, you know, papers you can find out there on particular PFAS.

01:23:25.000 --> 01:23:33.000
This table just gives a flavor for some of the available. Benchmarks that are currently out there.

01:23:33.000 --> 01:23:44.000
I give these references these references are all in the tech write document so you can refer back to that. She can see surface water has the most available benchmarks or standards.

01:23:44.000 --> 01:24:02.000
All the media that we evaluate, but. If you're looking for information on PFOS and PFOA and a handful of other PFOS compounds, it's out there right now and ready for use.

01:24:02.000 --> 01:24:17.000
So. Part of ecological risk assessment is not just looking at direct toxicity. We look at exposure, as well through the diet and we do that through food chain models.

01:24:17.000 --> 01:24:26.000
And with PFAS, again, this is, we would take a, an approach very similar to that, which we use for other types of contaminants.

01:24:26.000 --> 01:24:40.000
So. Understanding what your exposure point concentrations are, what different intake assumptions you use, what type of organism you use to evaluate that food chain model, you know.

01:24:40.000 --> 01:24:47.000
What's unique to your site? I don't think PFAS is really any different with respect to that.

01:24:47.000 --> 01:24:50.000
It's actually some of the PFAS are probably more well studied than some of the, other types of compounds that we routinely see.

01:24:50.000 --> 01:24:58.000
At hazardous waste sites. I think for estimating exposure, obviously the gold standard would be to collect tissue.

01:24:58.000 --> 01:25:10.000
Samples and see what you actually have in organisms. And so of course there are analytical challenges available.

01:25:10.000 --> 01:25:16.000
With that, so EPA just put out, their new, standard 1633 per and that includes tissue analysis.

01:25:16.000 --> 01:25:35.000
So today we are in a much better place than we were say 5 years ago with respect to the analysis of PFAS, at least in terms of having a more straightforward, consistent approach.

01:25:35.000 --> 01:25:45.000
I had already touched on the need for better bio accumulation models to account for bio accumulation and bio magnification of PFAS.

01:25:45.000 --> 01:25:54.000
Specifically a lot of our models that we use currently or for metals or for organic chlorine compounds and they do not necessarily apply.

01:25:54.000 --> 01:26:04.000
To be fast. So our typical models are not necessarily, useful at this stage. And I have touched upon how.

01:26:04.000 --> 01:26:10.000
Environmental modifiers like organic carbon or pH might be important and influencing uptake.

01:26:10.000 --> 01:26:13.000
And, I had already mentioned picking the appropriate toxicity reference values to estimate, risk to different types of organisms.

01:26:13.000 --> 01:26:24.000
So when you're picking your receptor of choice, do you have adequate TRVs to use?

01:26:24.000 --> 01:26:29.000
Are those, relevant to the receptors that you're looking at?

01:26:29.000 --> 01:26:33.000
And then as far as. Conducting a baseline ecological risk assessment. Again, PFAS is really not unique.

01:26:33.000 --> 01:26:45.000
You go through the very, basic steps that are set forth an EPA risk assessment guidance.

01:26:45.000 --> 01:27:02.000
And come up with a you know various lines of evidence to come up to a conclusion of risk or not so You could look at things like not only tissue concentrations, but you could look at toxicological analysis or wildlife surveys or so on and so forth.

01:27:02.000 --> 01:27:08.000
So again, he fast isn't really unique in that respect.

01:27:08.000 --> 01:27:28.000
So in conclusion, There is a wealth of data available for PFAS, but keep in mind that really is only available or PFAS, PFOS, PFOA, and then maybe a handful of other PFAS, as well as a very small number of species.

01:27:28.000 --> 01:27:42.000
So We know PFAS exposure is occurring. We know based on the toxicological information that's available that effects are highly variable across different types of media and across different types of organisms.

01:27:42.000 --> 01:27:50.000
And we know that environmental conditions appear to affect uptake and toxicity.

01:27:50.000 --> 01:28:02.000
But when we're evaluating the risk from PFAS for ecological receptors, you know, you need to understand what the data are, what the data are available.

01:28:02.000 --> 01:28:19.000
And what your uncertainties are. And use that information and interpretation of your results. There is guidance out there right now and there are benchmarks and various criteria out there for conducting screening level risk assessments.

01:28:19.000 --> 01:28:27.000
And there's ample information out there to help you through a baseline. Ecological risk assessment at this stage too.

01:28:27.000 --> 01:28:37.000
So just make sure you understand your uncertainties. In light of your conclusions. And so with that, I think.

01:28:37.000 --> 01:28:48.000
That is the end of my talk and I'm happy to entertain some questions.

01:28:48.000 --> 01:28:58.000
Thank you so much, Lisa. We are actually going to move. Into our next section and then we'll take questions at the end of the training module.

01:28:58.000 --> 01:28:59.000
Okay, sure.

01:28:59.000 --> 01:29:01.000
So we're going to pass it off to Bri.

01:29:01.000 --> 01:29:27.000
Sounds good.

01:29:27.000 --> 01:29:39.000
So, I am going to discuss some of our external tables, like the regulatory programs table and the groundwater soil and air quality values tables.

01:29:39.000 --> 01:29:51.000
I am going to touch a little bit on, well, most of it on section 8 about the regulations and then I'm also going to touch a little bit in section 3 on a triple F.

01:29:51.000 --> 01:30:04.000
So our regulatory programs table includes regulations as well as some policies and guidance from all 50 states and US territories including those with no applicable regulations.

01:30:04.000 --> 01:30:12.000
The federal government and some international entities. The goal of this table is to identify the program area and topic.

01:30:12.000 --> 01:30:19.000
With a brief description but not a detailed analysis. This table is intended to be a starting place for users.

01:30:19.000 --> 01:30:34.000
To research programs and regulations that are applicable in a given jurisdiction. This table is updated periodically so please if you have any updates provide them to the email listed on the slide.

01:30:34.000 --> 01:30:42.000
So here we have a screenshot of the states and territories table. So this is some of the information that we include.

01:30:42.000 --> 01:30:52.000
In these tables. And then a copy of or a screenshot of the federal. Regulations table.

01:30:52.000 --> 01:31:01.000
And a copy of or a screenshot of the International Regulations Table.

01:31:01.000 --> 01:31:09.000
The soil and water values tables include values for a number of PFAS compounds in soils and waters throughout the states.

01:31:09.000 --> 01:31:20.000
Federal and international agencies as available. Unlike the regulatory programs table, this table only includes those states with values.

01:31:20.000 --> 01:31:28.000
Developing these tables follows the same general process as the regulatory programs table, however, an effort is made to update this table monthly.

01:31:28.000 --> 01:31:33.000
The overall process involves many people to ensure that we are interpreting the regulations correctly and citing the proper information.

01:31:33.000 --> 01:31:42.000
It is a true team effort. If you have any updates just as with the other table, please send an email to the ITRC at ITRC web.

01:31:42.000 --> 01:31:49.000
Org email.

01:31:49.000 --> 01:32:05.000
So this is a screenshot of the December, 2023. Table and this water table includes health advisory, cleanup, screening, and other values pertinent to specific states or federally.

01:32:05.000 --> 01:32:13.000
The soils values tables. Now this is also a screenshot from. 2,023.

01:32:13.000 --> 01:32:20.000
This includes some cleanup screening and groundwater and surface water protection values pertinent to specific states or federally.

01:32:20.000 --> 01:32:31.000
Not every value of every type is listed. The specific type of value is identified at the top of the column.

01:32:31.000 --> 01:32:41.000
These maps include the values that are listed in the tables for drinking water, groundwater, soil as indicated and include values that were listed in the table.

01:32:41.000 --> 01:32:48.000
As of December, 2023. This demonstrates that waters tend to be regulated more broadly than soils.

01:32:48.000 --> 01:32:57.000
These maps and criteria Included in the tables are constantly changing.

01:32:57.000 --> 01:33:08.000
The data included in the tables shows that US EPA had no promulgated or final regulations for waters, soils as of December, the 20, th 23, although the tables do not yet reflect it.

01:33:08.000 --> 01:33:24.000
EPA has finalized drinking water rule, which I will discuss later. There are 9 states that have promulgated maximum contaminant levels, which include Massachusetts, Michigan, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont, and Wisconsin.

01:33:24.000 --> 01:33:34.000
There are a number of states and international agencies that have promulgated values for a number of different applications for both soils and groundwater.

01:33:34.000 --> 01:33:40.000
These international agencies are listed or countries are listed down at the bottom of the slide. The status of water and soil regulation is still quite variable globally.

01:33:40.000 --> 01:33:52.000
Waters tend to have more criteria than other media. The table that we have on the website is not an exhaustive list.

01:33:52.000 --> 01:34:01.000
It just captures a moment in time. Please verify any values with the regulatory agency you are working with.

01:34:01.000 --> 01:34:13.000
The air quality table includes all types of air criteria currently available within the US. The development of this table included compiling data from the ECOS, 2023 update.

01:34:13.000 --> 01:34:19.000
From the states on PFAS standards. As well as agency websites and ITRC team members.

01:34:19.000 --> 01:34:30.000
As with the other tables, please send any updates to the ITRC at ITRC web. Org email address.

01:34:30.000 --> 01:34:46.000
So there are no established federal PFAS air criteria at this time. Several state environmental agencies have published ambient air limits, risk assessment screening levels, and or reference concentrations for some PFAS.

01:34:46.000 --> 01:34:56.000
The ambient air limits. Shown in blue. Are limits not to be exceeded in modeling analyses for various permitting actions.

01:34:56.000 --> 01:35:05.000
Various types of screening levels. Shown in green have been established for risk assessment purposes but are not necessarily enforceable limits.

01:35:05.000 --> 01:35:14.000
Exceeding these thresholds can result in greater involvement by the regulators to address PFAS emissions and reduce impacts.

01:35:14.000 --> 01:35:44.000
Reference concentrations. Shown in gray are typically developed by state health or toxicology departments and are not yet utilized by air permitting agencies.

01:35:50.000 --> 01:35:57.000
Back to greater for acute exposures. On the other hand, the PFOS annual ESL.

01:35:57.000 --> 01:36:02.000
Is much less than the RFC, but the acute ESL is slightly greater. States May or may not publish the PFAS RFCs they have used as.

01:36:02.000 --> 01:36:15.000
Reference to derive their ambient air or screening values.

01:36:15.000 --> 01:36:26.000
The findings from the air quality tables are listed here. There are only 6 states with criteria. And as shown on the previous slide, there are 3 types of criteria that exist.

01:36:26.000 --> 01:36:37.000
Including ambient air limits. Screening model limits, and reference criteria.

01:36:37.000 --> 01:36:47.000
So moving on to a discussion of the federal regulations. The 2,018 NDAA was the 1st federal regulation that required action on PFAS.

01:36:47.000 --> 01:37:05.000
Every NDAA since 2018. Has had additional PFAS related requirements. These NDAAs required action from multiple federal agencies including but not limited to the Department of Defense, the CDC and ATSCR, and EPA.

01:37:05.000 --> 01:37:15.000
We will be discussing some individual agency actions in subsequent slides.

01:37:15.000 --> 01:37:31.000
So the Department of Defense as required by the NDAA has taken many steps over the ensuing years to not only locate facilities with PFAS impacts, but would start clean ups, testing service members and base firefighters blood for PFAS.

01:37:31.000 --> 01:37:38.000
Notifying local municipalities of potential contamination and starting to search for HRIPLEF alternatives.

01:37:38.000 --> 01:37:46.000
The Department of Defense currently has guidance. Documents to determine screening levels for assessments. Determination of the analytical method.

01:37:46.000 --> 01:38:00.000
And preferred disposal methods. DOD is also assessing health implications and research into remedial alternatives as well as replacement alternatives.

01:38:00.000 --> 01:38:08.000
The A triple F alternatives and replacements will be discussed a little later.

01:38:08.000 --> 01:38:09.000
The NDAA for 2,018 authorized CDC through ATSR to look at PFAS.

01:38:09.000 --> 01:38:26.000
Exposure in communities near current or former military bases. That are known to have had PFAS in their drinking water, groundwater, or other water sources.

01:38:26.000 --> 01:38:34.000
For example, part of the piece study was recently published, but studies are ongoing and no final decisions have been made.

01:38:34.000 --> 01:38:42.000
The FDA conducts scientific reviews of potential human health risks from dietary exposures to chemical contaminants.

01:38:42.000 --> 01:38:48.000
In food and regulates food. Contact substances such as PFAS as food additives.

01:38:48.000 --> 01:39:02.000
Food storage and food processing materials. As of February, 2024 the FDA released a statement that food packaging containing PFAS is no longer being sold in the US.

01:39:02.000 --> 01:39:10.000
So EPA has a number of programs that regulate or provide guidance for PFAS. Some of these are authorized by the NDA.

01:39:10.000 --> 01:39:22.000
Some of these programs are listed here for reference. The following slides will describe some of the actions included in each program.

01:39:22.000 --> 01:39:31.000
So the toxics released inventory. Was included in the NDA passed in 2020.

01:39:31.000 --> 01:39:42.000
This NDAA added numerous PFAS to the TRI. Most recent update to the TRI in January, 2024 added 7 more PFS.

01:39:42.000 --> 01:39:52.000
Making a total of over a hundred 90 pfas. The TRI program collects information about chemical releases and pollution prevention activities.

01:39:52.000 --> 01:40:05.000
From larger industrial and federal facilities. Do you, planning and community right to NATO Act allows EPA to add more PFS to the TRI annually as needed.

01:40:05.000 --> 01:40:13.000
The toxic substances control act or TASKA authorizes the US EPA to require reporting.

01:40:13.000 --> 01:40:23.000
Record keeping, testing, and restrictions of chemicals and chemical mixtures. That may pose risk to human health or the environment.

01:40:23.000 --> 01:40:30.000
TASKA authorizes the US EPA to issue significant new use rules for SNERS.

01:40:30.000 --> 01:40:35.000
There have been a number of SNERS issues since 2,002 regarding the use and import of PFAS with the list of compounds.

01:40:35.000 --> 01:40:46.000
Expanding and higher numbers of restrictions with each issuance.

01:40:46.000 --> 01:40:55.000
Circle. This rulemaking. Was passed, well. Finalized very recently as of last week.

01:40:55.000 --> 01:41:05.000
Requires entities to immediately report releases of PFOA and PFOS that meet or exceed the reportable quantity.

01:41:05.000 --> 01:41:06.000
These reports are made to the National Response Center, State or Tribal Emergency Response Commission.

01:41:06.000 --> 01:41:25.000
And the local or tribal emergency planning committee. Enities would not be required to report past releases as they were not yet listed listed as hazardous substances.

01:41:25.000 --> 01:41:32.000
This rule is expected to become a effective 60 days after the date of publication in the Federal Register.

01:41:32.000 --> 01:41:49.000
In addition to this final rule, EPA is issuing a separate circular enforcement discretion policy. It makes it clear that EPA will focus enforcement on parties who significantly contributed to the release of PFAS chemicals including parties that have manufactured PFAS.

01:41:49.000 --> 01:42:00.000
Or use PFAS in the manufacturing process. Federal facilities and other industrial, industrial parties. Rick Rock currently has 2 proposed rules.

01:42:00.000 --> 01:42:10.000
Both rules were proposed in February of 2024 the 1st proposes to expand the definition of a hazardous ways to encompass PFAS.

01:42:10.000 --> 01:42:26.000
The second list 9 new PFAS that are shown in the box on the slide. Adding these PFAS to the list of hazardous constituents will allow for the ability to require cleanup of these compounds.

01:42:26.000 --> 01:42:37.000
In 2,022. US CPA issued 2 memos, memos, providing guidance to the regions for increased monitoring and reporting of PFAS discharges.

01:42:37.000 --> 01:42:51.000
Through MPDES permitting. These include specific recommendations. For the various types of discharges including industrial facilities that are known or suspected to discharge PFAS.

01:42:51.000 --> 01:43:13.000
Publicly owned treatment works or wastewater treatment plants as well as various other potential sources. In January of 2023 EPA released its final affluent limitations guidelines or ELGs plan 15 including a determination that revised ELGs and pre-treatment standards.

01:43:13.000 --> 01:43:30.000
Are warranted for reducing PFAS and leachate discharges from landfills. This plan also included in an expansion of the ongoing study of discharges from textile manufacturers and wastewater treatment plants.

01:43:30.000 --> 01:43:38.000
Lisa mentioned earlier in 2,022 EPA proposed a product life criteria for PFOA and PFOS and Surface Water.

01:43:38.000 --> 01:43:46.000
These values have not yet been finalized.

01:43:46.000 --> 01:43:53.000
The Safe Drinking Water Act or SCWA requires that the EPA establish requirements for public water systems.

01:43:53.000 --> 01:44:02.000
To monitor for priority. Unregulated contaminants every 5 years and requires the agency to make the results publicly available.

01:44:02.000 --> 01:44:18.000
EPA uses the unregulated contaminant monitoring rule. UCMR. To collect data for contaminants that are suspected to be present in drinking water and do not have health-based standards set under the SDWA.

01:44:18.000 --> 01:44:30.000
The UCMR 3 included 6 PFAS, PFOS, PFOA, PFNA, PF H XS PF HPA and PFVS.

01:44:30.000 --> 01:44:41.000
This monitoring took place during a 12 month period from January, 2,013. Through December 2015 to provide data to drive future regulatory actions.

01:44:41.000 --> 01:44:52.000
The UCMR 5 was published on December, 27, th 2,021. This, the UCMR 5 requires sample collection for 30 chemical contaminants.

01:44:52.000 --> 01:45:03.000
Of which 29 are pefas. Between 2023 and 2,025 using analytical methods developed by EPA and consensus organizations.

01:45:03.000 --> 01:45:13.000
These analytical methods have lower reporting limits than the UCMR 3. UCMR 5 also includes more public water systems than UCMR 3.

01:45:13.000 --> 01:45:22.000
The purpose is to provide new data that will improve the agency's understanding of the frequency that PFAS are found in the nation's drinking water systems.

01:45:22.000 --> 01:45:31.000
And at what levels. As of February, the 1, st 2,024, EPA has released 3 rounds of data collected under the UCMR 5.

01:45:31.000 --> 01:45:42.000
The monitoring data on PFAS will help the EPA make determinations about future regulations and other actions to protect public health.

01:45:42.000 --> 01:45:52.000
As Linda discussed earlier on April 12,024, EPA announced finalization of MCLs for PFOA and PFOS individually.

01:45:52.000 --> 01:45:59.000
For PFNA, PF HXS and Genex individually provided they are not in a mixture.

01:45:59.000 --> 01:46:06.000
And PFNA, PF H XSS, PFPS and Gen X as a PFAS mixture.

01:46:06.000 --> 01:46:17.000
PFOA and PFOS are considered to be carcinogenic. So the MCLG is set at 0 while the MCL is as close as feasible to the MCLG.

01:46:17.000 --> 01:46:25.000
The MCL values include the evaluation of analytical method to detection limits as well as available treatment technologies.

01:46:25.000 --> 01:46:35.000
The other PFAS MCLs and MCLGs are based on systemic risk as well as assuming that the risk from all 4 is additive.

01:46:35.000 --> 01:46:43.000
As shown in the equation on the slide and as discussed earlier by Linda, this means that the MCL for the mixture is set at an HI.

01:46:43.000 --> 01:46:53.000
Or hazard index of one. With each PFAS HQ or hazard quotient ratio calculated using individual reference doses.

01:46:53.000 --> 01:46:57.000
Or health-based values suggested by the EPA.

01:46:57.000 --> 01:47:01.000
As well as the concentration in the drinking water sample. This rule will become final after publication in the Federal Register.

01:47:01.000 --> 01:47:16.000
EPA is giving public water systems 5 years to implement solutions. To reduce any PFAS exceedances that occur within the monitoring period.

01:47:16.000 --> 01:47:29.000
After these 1st 5 years, any violations water system that has violations of these MTLs must take action to reduce the levels of PFAS and must provide notification to the public.

01:47:29.000 --> 01:47:37.000
Of this violation.

01:47:37.000 --> 01:47:44.000
Federal MCLs are promulgated and enforceable regulations that all public water systems are required to follow.

01:47:44.000 --> 01:47:51.000
Because these MCLs are federally enforceable, the 9 states that I discussed earlier that have developed MCLs.

01:47:51.000 --> 01:48:01.000
Now need to evaluate how to proceed with enforcement because enforcement of the federal MCLs is conducted by the states.

01:48:01.000 --> 01:48:09.000
Adoption of the federal MCL. That state will now need to make the determination of which MCL to adopt.

01:48:09.000 --> 01:48:15.000
If the federal MTL is more stringent, the federal regulations require the adoption of those standards.

01:48:15.000 --> 01:48:21.000
If the state MCL is more stringent, it's up to the state agency. Responsible for enforcement.

01:48:21.000 --> 01:48:26.000
Which standard to adopt?

01:48:26.000 --> 01:48:39.000
Looking back at the DOD actions. We are going to. Move into the A triple F alternatives and replacement methods.

01:48:39.000 --> 01:48:54.000
As of February, 2,024 there are 2 military specimens F 3 or fluorine free phones approved for use on Class B fires at federal and FAA regulated for use on Class B fires at federal and FAA regulated facilities that require MA.

01:48:54.000 --> 01:49:02.000
Regulated facilities that require mill spec compliant, A triple F. Additional approved and certified military specific phones are expected to be available.

01:49:02.000 --> 01:49:18.000
An listed on the DOD qualified products database by the end of 2024. The mandate within the FAA reauthorization act of 2,018 that directs the FAA to stop requiring the use of fluorinated foam is now in effect.

01:49:18.000 --> 01:49:23.000
However, FAA is not requiring replacement.

01:49:23.000 --> 01:49:32.000
In accordance with the NDA, the Dod is ramping up on transitions in 2,024 for all LAMB-based applications.

01:49:32.000 --> 01:49:42.000
The FAA is starting to offer training and best management practices or BMPs. For F 3 use for aircraft rescue and firefighting.

01:49:42.000 --> 01:49:53.000
Industrial firefighting communities have started transitions where there are state-laws driving transition. Similar actions are occurring in other countries were driven by regulatory developments.

01:49:53.000 --> 01:50:06.000
For example, Canada. Although F threes are available firefighting training is ramping up substantially as BMPs are shifting from what was required for A triple F use.

01:50:06.000 --> 01:50:13.000
Youunicipal users appear to be lagging overall due to a lack of funds and or knowledge of need.

01:50:13.000 --> 01:50:24.000
Several states have developed take-back programs which has substantially helped ease the burden from municipal users. Training is still a priority as transition occurs.

01:50:24.000 --> 01:50:32.000
Several efforts are underway to evaluate F 3, A triple F replacements for environmental and human health effects.

01:50:32.000 --> 01:50:43.000
As well as performance effectiveness. SERDUP and ESTCP programs continue to fund several research and development projects to evaluate performance.

01:50:43.000 --> 01:50:59.000
Lifecycle impacts and health and safety implications of commercially available non fluorinated alternatives. Alternative assessments have been a mechanism to further evaluate F 3 alternatives in terms of regardable substitution.

01:50:59.000 --> 01:51:10.000
Tickner funded by CERTA completed an alternative assessment for A triple F. This assessment focused on understanding alternatives assessments completed.

01:51:10.000 --> 01:51:21.000
Supporting assessment and decisions about substitutes regarding safer and sufficient performance. As well as supporting needs related to adoption.

01:51:21.000 --> 01:51:30.000
This study developed 6 guiding considerations including Determine the function of the chemical of concern. For the specific application.

01:51:30.000 --> 01:51:42.000
Understand this function within the production chain. Define the application specific use scenarios. Identify alternatives that are fit for that particular purpose.

01:51:42.000 --> 01:51:54.000
Established and or used performance standards dependent independent of the standards. That are dependent on using chemicals or materials of concern.

01:51:54.000 --> 01:52:07.000
And adjust based on available alternatives or alternatives on the horizon. Use a range of performance standard benchmarks, for example, inadequate to sufficient to best in class.

01:52:07.000 --> 01:52:19.000
Consider technical performance separately from technical feasibility. Consult stakeholders for determining determining acceptable trade-offs between performance results.

01:52:19.000 --> 01:52:27.000
And other effects and other elements such as environmental health and safety.

01:52:27.000 --> 01:52:37.000
For DOD and FAA in January of 2,023 the new performance specification for F 3 land-based freshwater applications was released.

01:52:37.000 --> 01:52:45.000
This latest specification requires manufacturers to certify that PFAS has not been intentionally added to the formulation.

01:52:45.000 --> 01:52:59.000
And that the concentrate contains a maximum of one PPB of PFAS. As of February, 2024, there are 2 mill spec phones offered with more anticipated.

01:52:59.000 --> 01:53:08.000
For other phone users, the green screens certification process defines P fast-free. As 0 pthas intentionally added to the product.

01:53:08.000 --> 01:53:17.000
And PFAS contamination in the product less than point 0 0 0 1% by weight of the product.

01:53:17.000 --> 01:53:29.000
Or one part per 1 million of total organic fluorine. As of February, 2,024 there were nearly 4 dozen certified firefighting film products available.

01:53:29.000 --> 01:53:38.000
Please visit the website listed on the screen. For more information.

01:53:38.000 --> 01:53:47.000
Prior to foam and foam system replacement, performance specifications and system requirements need close consideration.

01:53:47.000 --> 01:54:04.000
The A triple F application design is specific for each foam and use. Changing between foam types or application objectives could require a complete system review and potentially a redesign and modification of system components.

01:54:04.000 --> 01:54:16.000
To meet the new objectives or material and performance requirements. When objectives or requirements are changed, each subject system should be evaluated and modified individually.

01:54:16.000 --> 01:54:29.000
To ensure that operational objectives are met. When considering foam replacement products, careful consideration to performance special specification requirements is essential.

01:54:29.000 --> 01:54:40.000
Whether considering flooring free foam alternatives or modern fluorotelmar phones. Not all films are created equal and decisions should be made based on specification requirements.

01:54:40.000 --> 01:54:59.000
And standards that are fit for the purpose of use. Also recalled that modern floratelimer foams may contain parts per 1 billion levels of PFOA and PFOA precursors as unintended byproducts and need to be managed accordingly.

01:54:59.000 --> 01:55:10.000
Though manufacturers should be consulted when a phone change is required and current best practices for phone replacement, system decontamination, and verification sampling should be considered.

01:55:10.000 --> 01:55:22.000
The degree of cleanliness required and the cost balance between cleaning and replacing system components. Should be considered during the planning phase of a foam concentrate change out.

01:55:22.000 --> 01:55:35.000
Currently, there are no regulatory guidelines or requirements pertaining to the cleanout of A triple F firefighting systems when foam concentrates containing legacy phones or replaced with alternative phones.

01:55:35.000 --> 01:55:51.000
However, local and state governments and other organizations continue to develop policy and guidance on replacing phones. In 2,018 DOD recommended a triple rinse using water heated or unheeded.

01:55:51.000 --> 01:55:57.000
That is employed after the old trip A triple F phone has been drained from the system and containerized.

01:55:57.000 --> 01:56:10.000
On March 5, th 2024 DOD released a new memo. That recommends a single water rinse for mobile systems that previously used H triple F and are transitioning to F 3.

01:56:10.000 --> 01:56:21.000
The state of Connecticut recommends a sitting time of 30 min with hot water or one to 2 h with cold water for municipal systems such as trailers or trucks.

01:56:21.000 --> 01:56:29.000
Note that there are no established standard guidelines for cleaning procedures due to the immense variety of foam delivery systems.

01:56:29.000 --> 01:56:40.000
That for which the procedures can vary greatly, even among the same manufacturer. All renting fluids and other waste generated during the system clean out process should be containerized.

01:56:40.000 --> 01:56:51.000
Labeled, and managed for proper future disposal. After the system has been cleaned out and rinse waters have been completely drained, new foam concentrate can be added.

01:56:51.000 --> 01:57:02.000
The practitioner should be aware that changing film products may necessitate changes to system components. Such as proportionors and discharge nozzles.

01:57:02.000 --> 01:57:11.000
There are 3 commonly used options for the disposal of A triple F concentrates and firewater containing high concentrations of A triple F.

01:57:11.000 --> 01:57:18.000
As a general approach, EPA encourages managers of PFAS and PFAS containing materials.

01:57:18.000 --> 01:57:24.000
To use destruction and disposal options that have a lower potential for releasing PFAS to the environment.

01:57:24.000 --> 01:57:48.000
As described in section one of Vpa's 2024 interim guidance. For more information on treatment and disposal options, the treatment technologies training will be providing that discussion.

01:57:48.000 --> 01:57:50.000
And I think that wraps up my section.

01:57:50.000 --> 01:57:51.000
Yes, thank you so much, Bree, and thank you so much to all of our trainers for today.

01:57:51.000 --> 01:57:59.000
We are close to time, but we will open our second and final question and answer session right now.

01:57:59.000 --> 01:58:11.000
As I've said previously at any time, you can type your questions into the Q&A pod in the bottom of your screen.

01:58:11.000 --> 01:58:14.000
And we're going to get through as many questions into the QA pod in the bottom of your screen.

01:58:14.000 --> 01:58:15.000
And we're going to get through as many questions as we can, while being mindful of everybody's time for today.

01:58:15.000 --> 01:58:45.000
So to get us started our 1st question. Is and I believe this is more geared toward Lisa but any of our trainers are welcome to answer with regard to surface water criteria, why might food chain exposure be a greater concern than direct toxicity to aquatic organisms.

01:58:45.000 --> 01:58:57.000
Yeah, I can answer that. So That's as I mentioned earlier in my slides, there's a propensity for certain types of PFAS to bio magnify through the food chain.

01:58:57.000 --> 01:59:03.000
So in other words, the higher up the food chain you go, the higher the concentration of P fast.

01:59:03.000 --> 01:59:15.000
So If you have a scenario where say a fish or, an aquatic in vertebrate is exposed through surface water or sediment.

01:59:15.000 --> 01:59:27.000
To PFAS, that concentration. For direct effects, you know, just from exposure to the impacted media.

01:59:27.000 --> 01:59:38.000
You said it one level. However, that concentration that accumulates in that organism can bio magnify so for.

01:59:38.000 --> 01:59:50.000
For wildlife such as herons that feed on the fish or ducks, you know, ducks that feed on the fish and then say birds of prey that feed on a dock.

01:59:50.000 --> 02:00:02.000
By the time, that top predator consumes the smaller predators, they're exposure could be much higher than that of a fish.

02:00:02.000 --> 02:00:11.000
So the water quality criteria for direct context doesn't take into account. That food chain pathway.

02:00:11.000 --> 02:00:28.000
So. You could be in a situation where your concentration surface water might not be so bad for fish or for a clam or for an aquatic plant, but the dose that the apex predators that those that are at the top of the food chain.

02:00:28.000 --> 02:00:38.000
Could be substantially higher and that levels at post toxic effects.

02:00:38.000 --> 02:00:52.000
Great. Thank you so much, Lisa. Moving on to our next question. Do you think there are currently adequate data to complete ecological risk assessment of

02:00:52.000 --> 02:01:04.000
I think it depends. I think yes. There's certainly enough data out there right now, for I would say at least PFOS and PFOA, we have inadequate data set.

02:01:04.000 --> 02:01:11.000
Probably more robust than we have for many of our standard. You know, constituents that we see at hazardous way sites.

02:01:11.000 --> 02:01:18.000
We certainly have guidance. Out there. We have screening benchmarks available that we can use, with which to evaluate.

02:01:18.000 --> 02:01:33.000
Ecological effects. So I think that for a small handful of chemicals, yes. For many other chemicals, I think there's just a lack of data currently to evaluate.

02:01:33.000 --> 02:01:37.000
The universe of compounds

02:01:37.000 --> 02:01:43.000
Alright, well thank you for answering those questions. Moving on to Bree, we have some questions for you as well.

02:01:43.000 --> 02:01:56.000
The 1st of which being do all of the tables include links to where our attendees could find more information.

02:01:56.000 --> 02:02:07.000
Yes, amazingly. All of our external tables have links. So the soil and water and air quality values tables have links to the specific states.

02:02:07.000 --> 02:02:22.000
Where all of their information is listed. The. Regulatory programs table has. Links to where you can find general information about the states and how they are handling PFAS.

02:02:22.000 --> 02:02:30.000
And you can dig deeper from the general. Excuse me, I'm sorry, website that we.

02:02:30.000 --> 02:02:33.000
Have referenced there.

02:02:33.000 --> 02:02:46.000
Excellent. Thank you so much. And then we do have time for one last question for you. Bree, which would be how often, are those tables typically updated?

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So it depends. The We attempt to update the soiling groundwater table monthly. It is turning out to be more of a quarterly thing because there are so many updates that have to be done.

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But we do make an attempt to do it monthly. The others as we do update as often as possible.

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So we are actually currently working on some of the updates. To the regulatory programs table. Again, if you have any updates for us, anything that we have wrong, anything that we have missing, please let us know on that ITRC at ITRC.

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Dot org. Website.

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Alright, excellent. Thank you so much, Bree, and thank you so much, to all of our trainers today.

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Unfortunately, we are out of time. For any more questions, but we really just want to reiterate, thank you to our trainers for being here today and to their contribution to the ITRC document.

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As well as thank you to all of our attendees for being here today. We would love to hear back from you.

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So please be sure to fill out the online feedback form. I am going to paste, the link right now.

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So everybody has access to that. Let me this in the chat so that all of our attendees.

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Have access to our feedback.

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All right, there we go. And, filling out this feedback for and certifying that you participated in the training today will allow you to receive a certificate of completion by email.

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If you do need any further clickation on answers or you would like to ask any more questions, please feel free to email us at ITRC at ITRC Web.

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Dot org. We will follow up with our trainers and we will do our very best to get as many of those questions answered as possible.

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So with that, you have reached the end of today's training module. Thank you.

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And, we hope you have a great rest of your day.