Environmental Fingerprinting

[00:00:00] [SPEAKER_00]: You might not realize it, but we are exposed to dozens of hazards every day.

[00:00:05] [SPEAKER_00]: Can any of these hazards negatively impact your health?

[00:00:09] [SPEAKER_00]: Definitely!

[00:00:10] [SPEAKER_00]: This is the Exposure Scientist Podcast.

[00:00:13] [SPEAKER_00]: My name is Alex LeBeau and here we answer your questions and concerns on what you may

[00:00:19] [SPEAKER_00]: be exposed to every day.

[00:00:21] [SPEAKER_00]: Welcome to the Exposure Scientist Podcast.

[00:00:25] [SPEAKER_00]: The views expressed in this podcast may not be those of the host or management.

[00:00:30] [SPEAKER_00]: This podcast is for informational purposes only and should not be considered health advice.

[00:00:34] [SPEAKER_00]: It is recommended that you consult an Exposure Scientist to discuss the particulars of your

[00:00:39] [SPEAKER_00]: exposure scenario.

[00:00:41] [SPEAKER_00]: Hello and welcome to today's episode of the Exposure Scientist Podcast.

[00:00:45] [SPEAKER_00]: Today we're going to be discussing an interesting topic, a topic that we've discussed previously,

[00:00:50] [SPEAKER_00]: from PFAS but from a different way of looking at PFAS back from the toxicological side but

[00:00:59] [SPEAKER_00]: more so from the environmental side.

[00:01:01] [SPEAKER_00]: So today we're going to be talking about PFAS source tracking using analytical fingerprinting.

[00:01:06] [SPEAKER_00]: That's an interesting topic and to introduce that topic and discuss it I've brought

[00:01:10] [SPEAKER_00]: somebody who is an expert in that field, Dr. Iwana Petrasior.

[00:01:14] [SPEAKER_00]: She is a Chief Chemist at NSafe.

[00:01:16] [SPEAKER_00]: Iwana, thank you very much for joining us today.

[00:01:19] [SPEAKER_01]: You're very welcome.

[00:01:20] [SPEAKER_01]: My pleasure.

[00:01:21] [SPEAKER_00]: Please tell us a little bit about yourself.

[00:01:25] [SPEAKER_01]: Oh yes, well so hello everyone.

[00:01:27] [SPEAKER_01]: I am a biochemist and as anyone can notice I am talking with an accent and this is

[00:01:34] [SPEAKER_01]: because I am originally from Romania which is in Eastern Europe.

[00:01:40] [SPEAKER_01]: So I was born and educated in Romania as a biochemist and I have been in the United

[00:01:46] [SPEAKER_01]: States since the beginning of 2001.

[00:01:51] [SPEAKER_01]: I have been a postdoctoral fellow at Florida State University, then at University of Southern

[00:01:58] [SPEAKER_01]: California in Los Angeles.

[00:02:00] [SPEAKER_01]: After that in 2003 I started my first consulting job and that was with an environmental

[00:02:08] [SPEAKER_01]: consulting company that basically my assignment with that company was to conduct forensics

[00:02:17] [SPEAKER_01]: investigations and it's really very exciting for me.

[00:02:21] [SPEAKER_01]: It's like conducting CSI type of investigations but that relates to the environmental

[00:02:26] [SPEAKER_01]: pollution which is also can be seen as a crime and as compared to criminal investigations

[00:02:33] [SPEAKER_01]: and criminal crime, environmental crime can be more outstanding because it can impact

[00:02:42] [SPEAKER_01]: more people.

[00:02:44] [SPEAKER_01]: And if the groundwater or the water, the drinking water source is contaminated

[00:02:51] [SPEAKER_01]: tens of thousands, hundreds of thousands, millions of people may be impacted.

[00:02:56] [SPEAKER_01]: And many times the impact is not immediate but with a lifetime exposure

[00:03:02] [SPEAKER_01]: people start developing cancers, they may have other chronic issues in later years

[00:03:09] [SPEAKER_01]: and certainly environmental pollution may contribute to this.

[00:03:18] [SPEAKER_01]: So my first consulting job was conduct environmental forensic studies which means

[00:03:25] [SPEAKER_01]: evaluating the source and the age of environmental contaminants

[00:03:31] [SPEAKER_01]: and with that job I changed several jobs, I worked for different companies along the

[00:03:38] [SPEAKER_01]: years but I kept doing this environmental CSI type of studies and I'm very proud

[00:03:45] [SPEAKER_01]: of this, I enjoy doing it.

[00:03:48] [SPEAKER_01]: More recently I am focused on these emerging contaminants that we refer to as PFAS,

[00:03:57] [SPEAKER_01]: parent poly fluorinated alkyl substances.

[00:04:03] [SPEAKER_00]: And I appreciate that and I wanted your expertise here to discuss those PFAS

[00:04:08] [SPEAKER_00]: substances, we hear it all the time there's lots of news articles, I don't think a day

[00:04:12] [SPEAKER_00]: goes by where I don't see a news article discussing PFAS in some form or fashion from

[00:04:16] [SPEAKER_00]: either contamination problem or groundwater problem or drinking water issue.

[00:04:20] [SPEAKER_00]: So if you could explain to the listeners, can you define PFAS for us?

[00:04:26] [SPEAKER_00]: Can you provide your characteristics to us?

[00:04:28] [SPEAKER_00]: And I know this is going to be a general term because as you'll listen to find out

[00:04:31] [SPEAKER_00]: there are lots of PFAS.

[00:04:33] [SPEAKER_00]: So if you could kind of give us a broad overview that would be very helpful.

[00:04:38] [SPEAKER_01]: Yes, of course it is very hard to clearly define PFAS and this is one issue related

[00:04:44] [SPEAKER_01]: to PFAS.

[00:04:45] [SPEAKER_01]: Well we have a name for them and I just mentioned it the abbreviation it's PFAS

[00:04:51] [SPEAKER_01]: and this is a class of chemicals.

[00:04:54] [SPEAKER_01]: So there are multiple chemicals that basically all of them have something in common.

[00:05:00] [SPEAKER_01]: They have carbon and fluorine in their structure because they have carbon because

[00:05:05] [SPEAKER_01]: they are carbon based these are organic chemicals.

[00:05:10] [SPEAKER_01]: However, there are many definitions out there related to what constitutes a PFAS

[00:05:18] [SPEAKER_01]: that go into the detail of their structure.

[00:05:23] [SPEAKER_01]: So some definitions would exclude compounds with double links, for example,

[00:05:30] [SPEAKER_01]: between in the carbon chain.

[00:05:33] [SPEAKER_01]: Some definitions maybe will include one or more fully fluorinated carbon atoms,

[00:05:40] [SPEAKER_01]: which means all the valencies of the carbons are filled by fluorine.

[00:05:49] [SPEAKER_01]: So we have just carbon and fluorine and also a terminal group.

[00:05:56] [SPEAKER_01]: So no hydrogen.

[00:05:58] [SPEAKER_01]: And the most inclusive definition that as far as I know it has not been

[00:06:06] [SPEAKER_01]: adopted by any governmental agency and may never be adopted, but the most inclusive one

[00:06:13] [SPEAKER_01]: would be that any organic compound that has carbon and fluorine in their formula

[00:06:20] [SPEAKER_01]: and in their structure would be a PFAS.

[00:06:24] [SPEAKER_01]: And that would mean potentially millions of chemicals out there.

[00:06:28] [SPEAKER_01]: But even if we refer to some more restrictive definitions that would include

[00:06:35] [SPEAKER_01]: fully fluorinated carbon atom, then we would still end up with at least 10,000

[00:06:44] [SPEAKER_01]: of these individual chemicals.

[00:06:47] [SPEAKER_01]: And you notice that in the name there are two types of chemicals.

[00:06:51] [SPEAKER_01]: We said pair and poly.

[00:06:54] [SPEAKER_01]: And that refers to a carbon atom if it is fully fluorinated or not,

[00:07:04] [SPEAKER_01]: which means if the carbon atom is only linked to fluorine and another carbon

[00:07:11] [SPEAKER_01]: or other carbons, it is considered that it is fully fluorinated.

[00:07:16] [SPEAKER_01]: And those are the pair compounds or the pair PFAS,

[00:07:23] [SPEAKER_01]: pair fluorinated PFAS that only have fully fluorinated carbon atoms in their structure.

[00:07:28] [SPEAKER_01]: The poly PFAS are those PFAS that have one or more carbon atoms in their structure.

[00:07:36] [SPEAKER_01]: And they could have 10, 12, 14, a larger number of carbon atoms starting with one

[00:07:44] [SPEAKER_01]: and going to many of them.

[00:07:47] [SPEAKER_01]: But if at least one of them is not fully fluorinated, which means it's linked to

[00:07:53] [SPEAKER_01]: fluorine, to another carbon, but may be linked to hydrogen.

[00:07:58] [SPEAKER_01]: Or another atom that is not carbon or fluorine.

[00:08:02] [SPEAKER_01]: So it is considered not fully fluorinated.

[00:08:04] [SPEAKER_01]: And those compounds would come in the category of poly PFAS or poly fluorinated PFAS.

[00:08:11] [SPEAKER_01]: Now, this is significant because carbon, the link between carbon and fluorine,

[00:08:18] [SPEAKER_01]: it is the strongest chemical link that we know so far.

[00:08:23] [SPEAKER_01]: Because of that, it is very hard to break.

[00:08:27] [SPEAKER_01]: So the pair PFAS or the pair fluorinated PFAS are extremely persistent in the environment.

[00:08:35] [SPEAKER_01]: We need very high energy input to break that link.

[00:08:39] [SPEAKER_01]: And this is how they are produced using high energy.

[00:08:42] [SPEAKER_01]: You need high energy to break the link.

[00:08:44] [SPEAKER_01]: So typically, that's why they are called forever chemicals.

[00:08:48] [SPEAKER_01]: Now, of course, forever chemicals, people use forever chemicals to refer to all the

[00:08:53] [SPEAKER_01]: PFAS compounds.

[00:08:54] [SPEAKER_01]: However, the poly PFAS, which are a large number of PFAS that are manufactured and used,

[00:09:04] [SPEAKER_01]: are not forever.

[00:09:06] [SPEAKER_01]: However, they will, the link that is not carbon and fluorine will break

[00:09:13] [SPEAKER_01]: and may break very easily in some cases.

[00:09:17] [SPEAKER_01]: But these PFAS will end up generating pair fluorinated PFAS.

[00:09:24] [SPEAKER_01]: With a smaller carbon number in their structure.

[00:09:30] [SPEAKER_01]: So therefore, even though they are not forever, they will break.

[00:09:35] [SPEAKER_01]: They will end up generating forever chemicals.

[00:09:38] [SPEAKER_01]: So I think the forever chemical name is correct to refer to the whole class of PFAS.

[00:09:50] [SPEAKER_00]: Exposure science covers a broad subject area, including toxicology, industrial hygiene,

[00:09:55] [SPEAKER_00]: and risk assessment.

[00:09:56] [SPEAKER_00]: From occupational, community or environmental exposure, exposure scientists apply

[00:10:02] [SPEAKER_00]: scientific methodologies to understand exposure risks and apply controls when necessary.

[00:10:08] [SPEAKER_00]: We at Exposure Assessment Consulting have this expertise.

[00:10:11] [SPEAKER_00]: Please reach out to us at info at exposureconsulting.com for a free 15 minute

[00:10:17] [SPEAKER_00]: consultation to discuss the specifics of your exposure scenario.

[00:10:28] [SPEAKER_00]: And listeners is want to just explain it's

[00:10:31] [SPEAKER_00]: there's a lot of chemicals in the class and there's a lot of, I'll say,

[00:10:36] [SPEAKER_00]: technical details.

[00:10:37] [SPEAKER_00]: So when people are talking about these, we hear the general term PFAS.

[00:10:41] [SPEAKER_00]: There's a lot of thought process that has to go into it from a number of different

[00:10:45] [SPEAKER_00]: standpoints when we're evaluating environmental deposition or exposure or toxicity to them.

[00:10:51] [SPEAKER_00]: So there's we hear this term PFAS.

[00:10:53] [SPEAKER_00]: People are looking for it now and drinking water.

[00:10:56] [SPEAKER_00]: Can you provide a little bit of the history, the backstory of what PFAS has been

[00:11:00] [SPEAKER_00]: traditionally used for and where has it ended up from that use?

[00:11:06] [SPEAKER_01]: Yes.

[00:11:06] [SPEAKER_01]: So I'll start with the end of your question because it's easier to explain.

[00:11:10] [SPEAKER_01]: PFAS are everywhere.

[00:11:11] [SPEAKER_01]: And when I say everywhere, I just don't mean in every environment,

[00:11:17] [SPEAKER_01]: everywhere on the planet.

[00:11:18] [SPEAKER_01]: It's also in all the living beings right now as far as we know, as far as we tested.

[00:11:25] [SPEAKER_01]: So really to find the human blood without PFAS, it's extremely rare.

[00:11:32] [SPEAKER_01]: I don't say it's impossible, but it will be extremely rare.

[00:11:36] [SPEAKER_01]: And typically, you know, any blood bank coming from before the Second World War

[00:11:42] [SPEAKER_01]: would be free of PFAS.

[00:11:45] [SPEAKER_01]: And this is because, and now I'm going back to the beginning of your question,

[00:11:49] [SPEAKER_01]: PFAS started being manufactured in the 40s and 50s.

[00:11:53] [SPEAKER_01]: Basically, they were commercially available on a larger scale since 1950s.

[00:11:59] [SPEAKER_01]: As far as I know, this is a consensus right now.

[00:12:03] [SPEAKER_01]: And their main use, well, they have multiple uses and we can go over those.

[00:12:09] [SPEAKER_01]: But one use that is very well known within the environmental community

[00:12:14] [SPEAKER_01]: and maybe within the public at large is their use in firefighting foams

[00:12:20] [SPEAKER_01]: or what we called AFFFs.

[00:12:24] [SPEAKER_01]: AFFF, which stands for a type of firefighting foams,

[00:12:30] [SPEAKER_01]: which are from the class B firefighting foams that are used to

[00:12:34] [SPEAKER_01]: treat fires that are very hard to treat, like petroleum fires.

[00:12:39] [SPEAKER_01]: Fires that are ignited and they have petroleum compounds as fuels.

[00:12:45] [SPEAKER_01]: And as everybody knows, if you want to start the fire

[00:12:47] [SPEAKER_01]: and you have some fuel oil there, you'll start it immediately.

[00:12:52] [SPEAKER_01]: And then without it.

[00:12:54] [SPEAKER_01]: So now, the reason that PFAS are used in firefighting foam

[00:13:00] [SPEAKER_01]: and in many other uses, it's because they have some specific characteristics

[00:13:07] [SPEAKER_01]: on top of being forever.

[00:13:11] [SPEAKER_01]: They have most of PFAS would have surfactant behavior

[00:13:16] [SPEAKER_01]: and surfactants are those compounds that are used in detergents.

[00:13:20] [SPEAKER_01]: All sorts of soaps and detergents.

[00:13:24] [SPEAKER_01]: Surfactants are compounds that have a hydrophobic

[00:13:29] [SPEAKER_01]: and the hydrophilic part in their structure.

[00:13:33] [SPEAKER_01]: And the hydrophobic segment or part would be repelling water

[00:13:38] [SPEAKER_01]: and would be the organic, the chain of carbon atoms.

[00:13:44] [SPEAKER_01]: And they can be linear or can be branched.

[00:13:48] [SPEAKER_01]: All PFAS would have carbon and fluorine, as we already discussed.

[00:13:54] [SPEAKER_01]: And that chain of carbons linked with each other

[00:13:58] [SPEAKER_01]: and with fluorine would constitute the hydrophobic part.

[00:14:02] [SPEAKER_01]: The hydrophilic part that most PFAS have are some sort of polar group.

[00:14:08] [SPEAKER_01]: And those would be electrically charged

[00:14:11] [SPEAKER_01]: and would be something like a carboxylic group.

[00:14:14] [SPEAKER_01]: That gives them acid behavior now and the acid name,

[00:14:18] [SPEAKER_01]: like any carboxylic acid.

[00:14:20] [SPEAKER_01]: So carboxylic could be one of these groups.

[00:14:25] [SPEAKER_01]: And it is very important that a sulfonic group,

[00:14:28] [SPEAKER_01]: it's another acid group that has sulfur in it.

[00:14:31] [SPEAKER_01]: Those constitute two major classes of PFAS that we studied so far.

[00:14:37] [SPEAKER_01]: And our regulations are focused on.

[00:14:39] [SPEAKER_01]: We charge a perfluoroalkyl carboxylic acid

[00:14:44] [SPEAKER_01]: and perfluoroalkyl sulfonic acids

[00:14:47] [SPEAKER_01]: or the so-called perfluoroalkyl acids.

[00:14:50] [SPEAKER_01]: There are other types of acids, many others

[00:14:53] [SPEAKER_01]: that are included as could be PFAS, but these are major ones.

[00:14:59] [SPEAKER_01]: So the carbon chain would give them hydrofolic,

[00:15:04] [SPEAKER_01]: would repel the water.

[00:15:05] [SPEAKER_01]: And this carboxylic or sulfonic group

[00:15:09] [SPEAKER_01]: or another type of polar group could be hydroxy,

[00:15:12] [SPEAKER_01]: could be a different type of group

[00:15:14] [SPEAKER_01]: would have the property of attracting

[00:15:20] [SPEAKER_01]: or of being dissolved in water if you like.

[00:15:23] [SPEAKER_01]: So because of that, PFAS have a series of peculiar characteristics

[00:15:31] [SPEAKER_01]: including that they would accumulate

[00:15:34] [SPEAKER_01]: at interfaces between different media

[00:15:37] [SPEAKER_01]: like water and air, water and soil, water and oil and so on.

[00:15:42] [SPEAKER_01]: They also many PFAS, most PFAS I would say

[00:15:45] [SPEAKER_01]: have this oleophilic behavior.

[00:15:53] [SPEAKER_01]: They really attract oil and also repel oil or organic compounds.

[00:15:58] [SPEAKER_01]: So basically that's a main property of PFAS

[00:16:04] [SPEAKER_01]: and that gives them detergent behavior, emulsifying behavior.

[00:16:10] [SPEAKER_01]: It's also the property of repelling water

[00:16:14] [SPEAKER_01]: and a lot of waterproof things that we know

[00:16:18] [SPEAKER_01]: and we have and we use every day

[00:16:20] [SPEAKER_01]: and including coatings for carpets

[00:16:22] [SPEAKER_01]: and the many consumer products

[00:16:24] [SPEAKER_01]: this outdoor equipment, the raincoats that are resistant

[00:16:31] [SPEAKER_01]: and they don't get wet, rain shoes and so on,

[00:16:36] [SPEAKER_01]: waxes, they all have PFAS in them

[00:16:39] [SPEAKER_01]: because PFAS are very useful.

[00:16:44] [SPEAKER_01]: The Teflon coatings in the Teflon tans

[00:16:46] [SPEAKER_01]: and with this being said, a lot of consumer products

[00:16:50] [SPEAKER_01]: if not the majority of consumer products

[00:16:53] [SPEAKER_01]: have some PFAS in them, some PFAS compounds

[00:16:56] [SPEAKER_01]: because really they provide very good water repellents,

[00:17:01] [SPEAKER_01]: oil repellents properties, temperature stability

[00:17:06] [SPEAKER_01]: as well as some properties that help those products last more

[00:17:13] [SPEAKER_01]: and serve their purpose.

[00:17:16] [SPEAKER_01]: We all know how useful the Teflon tan was when introduced

[00:17:20] [SPEAKER_01]: and how much you have to scratch and clean a pan

[00:17:24] [SPEAKER_01]: if it's not Teflon or if it doesn't have a coating on it

[00:17:26] [SPEAKER_01]: that will repel water.

[00:17:29] [SPEAKER_01]: We are so used to these types of pans

[00:17:32] [SPEAKER_01]: that if we go back to the other pans

[00:17:33] [SPEAKER_01]: it will be a lot of work to clean them.

[00:17:37] [SPEAKER_01]: So PFAS are the main culprits

[00:17:39] [SPEAKER_01]: but of course they help us in many ways

[00:17:42] [SPEAKER_01]: and they're very helpful in semi.

[00:17:45] [SPEAKER_01]: For example, another example would be

[00:17:47] [SPEAKER_01]: in computer chips and semiconductors

[00:17:50] [SPEAKER_01]: PFAS have a very important role

[00:17:52] [SPEAKER_01]: and that role right now it's unreplaceable.

[00:17:57] [SPEAKER_01]: It looks to be unreplaceable

[00:17:59] [SPEAKER_01]: that hopefully will be replacement chemicals

[00:18:02] [SPEAKER_01]: but in some situations PFAS have very essential role.

[00:18:08] [SPEAKER_01]: In some situations they are just a commodity

[00:18:11] [SPEAKER_01]: but nevertheless they are used by many industries

[00:18:16] [SPEAKER_01]: and they are in many consumer products

[00:18:20] [SPEAKER_01]: and in many products

[00:18:21] [SPEAKER_01]: and certainly we found them in all the environments

[00:18:26] [SPEAKER_01]: even in the Arctic pole in that ice

[00:18:31] [SPEAKER_01]: because they travel.

[00:18:33] [SPEAKER_00]: Right, no and I think it's to add some context from that

[00:18:36] [SPEAKER_00]: and you're talking about the AFFF foam

[00:18:38] [SPEAKER_00]: and I think it's important to provide this to the listeners.

[00:18:41] [SPEAKER_00]: Of course it's used in firefighting

[00:18:43] [SPEAKER_00]: but you have to think it's not the fact that there's that many fires

[00:18:48] [SPEAKER_00]: it's the fact that these materials were used

[00:18:50] [SPEAKER_00]: in training of firefighters very often

[00:18:53] [SPEAKER_00]: without understanding the full implications or ramifications

[00:18:56] [SPEAKER_00]: of just simply washing it off into the side of the road

[00:19:00] [SPEAKER_00]: or what have you.

[00:19:02] [SPEAKER_00]: It's not just the limited use of it

[00:19:03] [SPEAKER_00]: they were also used in training modules

[00:19:07] [SPEAKER_00]: for firefighters all across the United States.

[00:19:11] [SPEAKER_01]: Absolutely, yeah.

[00:19:12] [SPEAKER_01]: You are absolutely right.

[00:19:15] [SPEAKER_01]: So of course PFAS had the important uses to treat

[00:19:19] [SPEAKER_01]: or put off the fires, petroleum fires

[00:19:22] [SPEAKER_01]: and that was one way they spread in the environment.

[00:19:27] [SPEAKER_01]: However an important way they got into our environment

[00:19:32] [SPEAKER_01]: is just by training

[00:19:33] [SPEAKER_01]: and right now I don't think anyone in the US

[00:19:38] [SPEAKER_01]: is conducting training, active training

[00:19:40] [SPEAKER_01]: firefighting training using AFFFs anymore

[00:19:43] [SPEAKER_01]: and I know that there is an active campaign

[00:19:46] [SPEAKER_01]: to replace the AFFF foams with non-fluorinated foams

[00:19:50] [SPEAKER_01]: which is really great

[00:19:52] [SPEAKER_01]: but in the past fire training used AFFF

[00:19:58] [SPEAKER_01]: and they were just going down the drain.

[00:20:01] [SPEAKER_00]: I'll ask this question

[00:20:02] [SPEAKER_00]: and again in recent years

[00:20:06] [SPEAKER_00]: a lot of this from what I understand

[00:20:08] [SPEAKER_00]: the firefighting because petroleum fires

[00:20:11] [SPEAKER_00]: they practice at airports

[00:20:12] [SPEAKER_00]: they practice in areas where they're going to have

[00:20:14] [SPEAKER_00]: a large petroleum issue.

[00:20:16] [SPEAKER_00]: A few years ago I say 10, 15 years ago

[00:20:19] [SPEAKER_00]: I think there was an FAA was kind of looking

[00:20:21] [SPEAKER_00]: at this federal aviation administration saying

[00:20:23] [SPEAKER_00]: okay maybe we should look at the shorter chain PFAS

[00:20:26] [SPEAKER_00]: to use in these scenarios.

[00:20:29] [SPEAKER_00]: Have you seen anything with using

[00:20:31] [SPEAKER_00]: and changing it to different PFAS

[00:20:34] [SPEAKER_00]: for using these scenarios

[00:20:35] [SPEAKER_00]: and how they interact with the environment

[00:20:38] [SPEAKER_00]: from their use and maybe in training

[00:20:40] [SPEAKER_00]: and more recent years

[00:20:42] [SPEAKER_00]: as opposed to training in the 70s or 80s

[00:20:45] [SPEAKER_00]: again if we're talking about something

[00:20:46] [SPEAKER_00]: that will last or persist forever.

[00:20:49] [SPEAKER_01]: Yes, as a matter of fact since about 2012

[00:20:53] [SPEAKER_01]: I think most of the manufacturer firefighting foam

[00:20:59] [SPEAKER_01]: that had PFAS in it like AFFF

[00:21:02] [SPEAKER_01]: is what we like to refer to as modern foam

[00:21:07] [SPEAKER_01]: this would be a C6 or lower foam

[00:21:11] [SPEAKER_01]: which means the older foam had eight compounds

[00:21:17] [SPEAKER_01]: with PFAS compounds with eight carbon atoms

[00:21:20] [SPEAKER_01]: and more and also with lower carbon atoms

[00:21:23] [SPEAKER_01]: but then the modern firefighting foam

[00:21:28] [SPEAKER_01]: tried to eliminate these long chain PFAS

[00:21:32] [SPEAKER_01]: that have eight carbon atoms

[00:21:34] [SPEAKER_01]: like PFOA, PFOS those are pretty famous PFAS

[00:21:39] [SPEAKER_01]: that are already regulated by EPA in various ways

[00:21:44] [SPEAKER_01]: but they still have PFAS these modern forms

[00:21:49] [SPEAKER_01]: or they generate you know they have mostly

[00:21:52] [SPEAKER_01]: most of them would have these poly PFAS

[00:21:55] [SPEAKER_01]: poly compounds which are not fully fluorinated compounds

[00:21:59] [SPEAKER_01]: but those compounds would generate PFAS

[00:22:03] [SPEAKER_01]: per fluorinated PFAS with six carbon atoms or less

[00:22:08] [SPEAKER_01]: and the general idea is the shorter the chain

[00:22:13] [SPEAKER_01]: the less problematic the PFAS is

[00:22:15] [SPEAKER_01]: from the point of view of persistence

[00:22:17] [SPEAKER_01]: of health effects and so on

[00:22:21] [SPEAKER_01]: however recent studies I mean studies

[00:22:28] [SPEAKER_01]: that these replacement PFAS

[00:22:31] [SPEAKER_01]: including replacement AFFF forms

[00:22:33] [SPEAKER_01]: are still problematic

[00:22:34] [SPEAKER_01]: and maybe we have less toxicity

[00:22:37] [SPEAKER_01]: but they are still toxic

[00:22:38] [SPEAKER_01]: and some of them may be carcinogenic to humans

[00:22:40] [SPEAKER_01]: and certainly all the per fluorinated PFAS

[00:22:45] [SPEAKER_01]: are kind of forever now I mean

[00:22:47] [SPEAKER_01]: unless we do something actively

[00:22:49] [SPEAKER_01]: they will persist in the environment

[00:22:51] [SPEAKER_01]: they will move between soil water air

[00:22:54] [SPEAKER_01]: and they will recycle

[00:22:56] [SPEAKER_01]: and they can move over long distances

[00:22:59] [SPEAKER_01]: via air and ocean water

[00:23:01] [SPEAKER_01]: and reach the poles

[00:23:03] [SPEAKER_01]: and basically we found now

[00:23:06] [SPEAKER_01]: we found them in all the environments

[00:23:10] [SPEAKER_01]: we look for them

[00:23:11] [SPEAKER_01]: so because of that

[00:23:14] [SPEAKER_01]: and because you know it's very hard

[00:23:18] [SPEAKER_01]: to study every single PFAS

[00:23:20] [SPEAKER_01]: I mean there could be tens of thousands

[00:23:22] [SPEAKER_01]: or even more PFAS

[00:23:24] [SPEAKER_01]: maybe some of them could be fine

[00:23:27] [SPEAKER_01]: but it is absolutely impractical

[00:23:30] [SPEAKER_01]: and infeasible to study all of them

[00:23:34] [SPEAKER_01]: people try to move away

[00:23:35] [SPEAKER_01]: from the PFAS as a class

[00:23:37] [SPEAKER_01]: and that's another thing

[00:23:39] [SPEAKER_01]: that it really makes PFAS

[00:23:40] [SPEAKER_01]: make PFAS apart from other chemicals

[00:23:45] [SPEAKER_01]: because the tendency is to regulate

[00:23:48] [SPEAKER_01]: or to eliminate them

[00:23:51] [SPEAKER_01]: to treat them as a class

[00:23:53] [SPEAKER_01]: rather than individual compounds

[00:23:57] [SPEAKER_01]: and basically move away from PFAS

[00:24:00] [SPEAKER_01]: and any industrial company

[00:24:05] [SPEAKER_01]: and any companies that has PFAS issues

[00:24:07] [SPEAKER_01]: know that and they start being very aware

[00:24:11] [SPEAKER_01]: and try to stay away

[00:24:13] [SPEAKER_01]: from any sort of PFAS

[00:24:15] [SPEAKER_01]: because even if they are not regulated today

[00:24:18] [SPEAKER_01]: it could be regulated tomorrow as a class

[00:24:20] [SPEAKER_01]: or as individual PFAS

[00:24:22] [SPEAKER_01]: so yes there are alternatives

[00:24:24] [SPEAKER_01]: there is this modern

[00:24:25] [SPEAKER_01]: that has been used in the past decade

[00:24:28] [SPEAKER_01]: or more almost exclusively

[00:24:32] [SPEAKER_01]: however all the legacy

[00:24:35] [SPEAKER_01]: with long chain PFAS still exist

[00:24:38] [SPEAKER_01]: and still exists in many locations

[00:24:40] [SPEAKER_01]: it has a very long shelf life

[00:24:42] [SPEAKER_01]: so even if that was not manufactured

[00:24:46] [SPEAKER_01]: starting in the beginning of 2000s

[00:24:49] [SPEAKER_01]: a lot of it still exists

[00:24:52] [SPEAKER_01]: and it is stored in various locations

[00:24:54] [SPEAKER_01]: when you store something

[00:24:56] [SPEAKER_01]: like with petroleum products

[00:24:57] [SPEAKER_01]: you may have spills

[00:24:58] [SPEAKER_01]: you may have leaks

[00:24:59] [SPEAKER_01]: some of them you know

[00:25:00] [SPEAKER_01]: some of them you may not know

[00:25:01] [SPEAKER_01]: and it was still used

[00:25:06] [SPEAKER_01]: in firefighting training for some time

[00:25:11] [SPEAKER_01]: it all depends

[00:25:11] [SPEAKER_01]: it varies but there are situations

[00:25:14] [SPEAKER_01]: where it could have been used

[00:25:16] [SPEAKER_01]: as you know almost very recently

[00:25:19] [SPEAKER_01]: or in the past five years or so

[00:25:22] [SPEAKER_01]: so we cannot exclude the use

[00:25:25] [SPEAKER_01]: of the legacy firefighting form

[00:25:27] [SPEAKER_01]: even though it was not manufactured

[00:25:28] [SPEAKER_01]: and you know in general

[00:25:31] [SPEAKER_01]: all the companies try to move away from it

[00:25:35] [SPEAKER_00]: Right so we've had

[00:25:36] [SPEAKER_00]: and I appreciate that

[00:25:37] [SPEAKER_00]: we've had this conversation about

[00:25:40] [SPEAKER_00]: use of it in the environment

[00:25:42] [SPEAKER_00]: from I'll say industrial type scenarios

[00:25:47] [SPEAKER_00]: and you know personal products as well

[00:25:50] [SPEAKER_00]: that consumer products

[00:25:51] [SPEAKER_00]: as you talked about

[00:25:53] [SPEAKER_00]: and if we're finding these chemicals

[00:25:56] [SPEAKER_00]: you know if they are persistent

[00:25:58] [SPEAKER_00]: from use from deposition

[00:26:01] [SPEAKER_00]: from industrial use

[00:26:02] [SPEAKER_00]: from spills or whatever

[00:26:03] [SPEAKER_00]: you know I want to kind of get into

[00:26:05] [SPEAKER_00]: you'd mentioned earlier

[00:26:07] [SPEAKER_00]: your forensic investigative techniques

[00:26:09] [SPEAKER_00]: or forensic investigation

[00:26:11] [SPEAKER_00]: finding out what techniques you use

[00:26:13] [SPEAKER_00]: to identify these and sources

[00:26:15] [SPEAKER_00]: discussing you know how PFAS

[00:26:18] [SPEAKER_00]: again as a group as you mentioned

[00:26:20] [SPEAKER_00]: may be different from other chemicals

[00:26:23] [SPEAKER_00]: when you're doing

[00:26:24] [SPEAKER_00]: your environmental investigation

[00:26:25] [SPEAKER_00]: so I'd like to be able to talk about

[00:26:27] [SPEAKER_00]: your analytical methods

[00:26:29] [SPEAKER_00]: you use to identify these

[00:26:31] [SPEAKER_00]: and how you see these

[00:26:34] [SPEAKER_00]: as use and limitations

[00:26:36] [SPEAKER_00]: of the many types of techniques

[00:26:37] [SPEAKER_00]: that are available

[00:26:39] [SPEAKER_01]: Right that's a very good question

[00:26:41] [SPEAKER_01]: so as a forensic scientist

[00:26:44] [SPEAKER_01]: I have used a large variety

[00:26:46] [SPEAKER_01]: of environmental forensic techniques

[00:26:48] [SPEAKER_01]: I wrote articles, editorials

[00:26:52] [SPEAKER_01]: I didn't mention I'm also editor

[00:26:53] [SPEAKER_01]: of environmental forensics journal

[00:26:55] [SPEAKER_01]: and by the way

[00:26:56] [SPEAKER_01]: whoever is interested from the audience

[00:26:58] [SPEAKER_01]: you can consult the journal

[00:26:59] [SPEAKER_01]: or send something for journal

[00:27:01] [SPEAKER_01]: and I also wrote a book

[00:27:03] [SPEAKER_01]: on environmental forensics

[00:27:05] [SPEAKER_01]: and we have a large

[00:27:07] [SPEAKER_01]: very large variety of

[00:27:09] [SPEAKER_01]: environmental forensic techniques

[00:27:11] [SPEAKER_01]: that we can use to study

[00:27:13] [SPEAKER_01]: environmental contaminants

[00:27:14] [SPEAKER_01]: and fingerprints them

[00:27:16] [SPEAKER_01]: in order to evaluate their source and age

[00:27:20] [SPEAKER_01]: out of those techniques

[00:27:21] [SPEAKER_01]: there are very few

[00:27:23] [SPEAKER_01]: very limited number of techniques

[00:27:26] [SPEAKER_01]: can be applied to PFAS

[00:27:28] [SPEAKER_01]: for example

[00:27:29] [SPEAKER_01]: and I'm going to talk more

[00:27:31] [SPEAKER_01]: about those in a moment

[00:27:32] [SPEAKER_01]: but for example

[00:27:33] [SPEAKER_01]: a lot of people may be aware

[00:27:35] [SPEAKER_01]: of the isotopes

[00:27:37] [SPEAKER_01]: we both have we have both stable

[00:27:39] [SPEAKER_01]: and radioisotopes

[00:27:41] [SPEAKER_01]: and many people may be aware

[00:27:43] [SPEAKER_01]: of carbon dating

[00:27:44] [SPEAKER_01]: of archaeological sites

[00:27:46] [SPEAKER_01]: now using

[00:27:50] [SPEAKER_01]: radioactive isotopes

[00:27:53] [SPEAKER_01]: and or age dating in general

[00:27:55] [SPEAKER_01]: using radioactive isotopes

[00:27:57] [SPEAKER_01]: and maybe less people are aware

[00:27:59] [SPEAKER_01]: but many environmental people

[00:28:01] [SPEAKER_01]: are aware that when we have

[00:28:03] [SPEAKER_01]: chlorinated solvent spills

[00:28:04] [SPEAKER_01]: for example we isotopic

[00:28:07] [SPEAKER_01]: stabilized isotopic testing

[00:28:09] [SPEAKER_01]: stable carbon as opposed to

[00:28:12] [SPEAKER_01]: radioactive carbon

[00:28:13] [SPEAKER_01]: stable carbon isotope

[00:28:15] [SPEAKER_01]: can be used in various ways

[00:28:18] [SPEAKER_01]: to evaluate the source

[00:28:20] [SPEAKER_01]: get a fingerprint

[00:28:20] [SPEAKER_01]: to evaluate fate and transport

[00:28:22] [SPEAKER_01]: because it you know

[00:28:24] [SPEAKER_01]: that stabilized isotope

[00:28:25] [SPEAKER_01]: will change in composition

[00:28:28] [SPEAKER_01]: when a contaminant

[00:28:30] [SPEAKER_01]: gets weathered

[00:28:32] [SPEAKER_01]: biodegraded and so on

[00:28:34] [SPEAKER_01]: this technique is not available

[00:28:37] [SPEAKER_01]: for PFAS unfortunately

[00:28:39] [SPEAKER_01]: and even though it may have potential

[00:28:43] [SPEAKER_01]: as far as I know

[00:28:44] [SPEAKER_01]: we do not have a way to handle

[00:28:49] [SPEAKER_01]: the hydrofluoric acid

[00:28:51] [SPEAKER_01]: that may be produced

[00:28:52] [SPEAKER_01]: when we test via this technique

[00:28:54] [SPEAKER_01]: and it will really

[00:28:56] [SPEAKER_01]: degrade the equipment

[00:28:57] [SPEAKER_01]: so I don't see it coming

[00:29:00] [SPEAKER_01]: in the near future

[00:29:01] [SPEAKER_01]: I might be wrong

[00:29:02] [SPEAKER_01]: I mean there could be

[00:29:03] [SPEAKER_01]: all sorts of advancements

[00:29:04] [SPEAKER_01]: we should keep an eye

[00:29:05] [SPEAKER_01]: but right now isotopes

[00:29:08] [SPEAKER_01]: are not a technique

[00:29:10] [SPEAKER_01]: that is applied for PFAS

[00:29:13] [SPEAKER_01]: so what do we have

[00:29:14] [SPEAKER_01]: when we talk about PFAS

[00:29:16] [SPEAKER_01]: we have the chemical analysis

[00:29:18] [SPEAKER_01]: that's how we know

[00:29:19] [SPEAKER_01]: PFAS are in environment

[00:29:21] [SPEAKER_01]: and in human blood

[00:29:22] [SPEAKER_01]: and in animals

[00:29:24] [SPEAKER_01]: because we chemically test

[00:29:25] [SPEAKER_01]: for individual PFAS

[00:29:28] [SPEAKER_01]: and we have all sorts of variations

[00:29:30] [SPEAKER_01]: of the chemical analysis

[00:29:32] [SPEAKER_01]: I'm going to talk about right now

[00:29:34] [SPEAKER_01]: there are four types of variations

[00:29:37] [SPEAKER_01]: of this chemical analysis

[00:29:39] [SPEAKER_01]: that are distinct techniques

[00:29:42] [SPEAKER_01]: that we can use

[00:29:44] [SPEAKER_01]: in environmental forensics

[00:29:46] [SPEAKER_01]: looking at PFAS sources

[00:29:47] [SPEAKER_01]: or trying to get more details

[00:29:49] [SPEAKER_01]: of a PFAS release

[00:29:51] [SPEAKER_01]: but any of these techniques

[00:29:53] [SPEAKER_01]: could be applied

[00:29:54] [SPEAKER_01]: outside the environmental forensics

[00:29:57] [SPEAKER_01]: context

[00:29:58] [SPEAKER_01]: to better understand

[00:29:59] [SPEAKER_01]: what PFAS are released

[00:30:01] [SPEAKER_01]: how they were released

[00:30:03] [SPEAKER_01]: where are the main sources

[00:30:05] [SPEAKER_01]: in order to eliminate

[00:30:06] [SPEAKER_01]: and take care of that release

[00:30:09] [SPEAKER_01]: and make sure we clean everything

[00:30:13] [SPEAKER_01]: that was released

[00:30:14] [SPEAKER_01]: so the main technique

[00:30:16] [SPEAKER_01]: that people know

[00:30:19] [SPEAKER_01]: or environment people

[00:30:21] [SPEAKER_01]: that conduct environmental studies now

[00:30:23] [SPEAKER_01]: is the so-called chemical fingerprinting

[00:30:26] [SPEAKER_01]: or targeted chemical analysis

[00:30:29] [SPEAKER_01]: of PFAS

[00:30:29] [SPEAKER_01]: and targeted means

[00:30:30] [SPEAKER_01]: we are looking for

[00:30:33] [SPEAKER_01]: a number of individual PFAS compounds

[00:30:35] [SPEAKER_01]: and these PFAS compounds

[00:30:38] [SPEAKER_01]: are from both perfluinated PFAS

[00:30:41] [SPEAKER_01]: and polyfluinated PFAS classes

[00:30:43] [SPEAKER_01]: but what defines this technique

[00:30:46] [SPEAKER_01]: is we need standards

[00:30:48] [SPEAKER_01]: for these individual PFAS compounds

[00:30:50] [SPEAKER_01]: so PFAS individual PFAS compounds

[00:30:53] [SPEAKER_01]: with non-standards

[00:30:56] [SPEAKER_01]: can be tested

[00:30:57] [SPEAKER_01]: via this targeted chemical analysis

[00:31:00] [SPEAKER_01]: which is very reliable

[00:31:02] [SPEAKER_01]: there are a series of EPA

[00:31:04] [SPEAKER_01]: and ASTM methods

[00:31:06] [SPEAKER_01]: that can be used

[00:31:09] [SPEAKER_01]: depending on the media

[00:31:10] [SPEAKER_01]: for example for drinking water

[00:31:12] [SPEAKER_01]: there are two main methods

[00:31:15] [SPEAKER_01]: that are used

[00:31:15] [SPEAKER_01]: and are currently used

[00:31:16] [SPEAKER_01]: by water utilities

[00:31:17] [SPEAKER_01]: that are testing for PFAS

[00:31:19] [SPEAKER_01]: under the UCMR 5 testing

[00:31:23] [SPEAKER_01]: and those methods

[00:31:25] [SPEAKER_01]: are the EPA 537.1

[00:31:29] [SPEAKER_01]: and the other method is

[00:31:31] [SPEAKER_01]: EPA method 533

[00:31:34] [SPEAKER_01]: and they are these methods

[00:31:36] [SPEAKER_01]: basically look

[00:31:37] [SPEAKER_01]: or most of the individual PFAS

[00:31:39] [SPEAKER_01]: are common between these methods

[00:31:41] [SPEAKER_01]: very few can only be done

[00:31:44] [SPEAKER_01]: by 537.1

[00:31:48] [SPEAKER_01]: and 533

[00:31:49] [SPEAKER_01]: it's typically preferred by regulators

[00:31:52] [SPEAKER_01]: and this is why

[00:31:53] [SPEAKER_01]: for the UCMR 5 testing

[00:31:55] [SPEAKER_01]: water utilities have to test twice

[00:31:57] [SPEAKER_01]: using both of these methods

[00:31:59] [SPEAKER_01]: and the number of PFAS

[00:32:03] [SPEAKER_01]: they test for a total of 29 PFAS

[00:32:05] [SPEAKER_01]: the number I think for PFAS

[00:32:06] [SPEAKER_01]: which are not included in 533

[00:32:09] [SPEAKER_01]: would be reported

[00:32:10] [SPEAKER_01]: based on the 537.1 method

[00:32:13] [SPEAKER_01]: and for environment

[00:32:16] [SPEAKER_01]: for anything else

[00:32:17] [SPEAKER_01]: and drinking water

[00:32:18] [SPEAKER_01]: basically any environmental media

[00:32:20] [SPEAKER_01]: including waste

[00:32:23] [SPEAKER_01]: and environmental bio-tissues

[00:32:26] [SPEAKER_01]: we can use another EPA method

[00:32:30] [SPEAKER_01]: which was recently basically finalized

[00:32:33] [SPEAKER_01]: that is EPA method 1633

[00:32:37] [SPEAKER_01]: and that method

[00:32:38] [SPEAKER_01]: it's looking at a total of 40

[00:32:41] [SPEAKER_01]: individual PFAS compounds

[00:32:43] [SPEAKER_01]: so these methods

[00:32:44] [SPEAKER_01]: are extremely reliable

[00:32:45] [SPEAKER_01]: are pretty well developed

[00:32:50] [SPEAKER_01]: and standardized

[00:32:51] [SPEAKER_01]: and it will give you 40 PFAS

[00:32:55] [SPEAKER_01]: in your environmental sample

[00:32:57] [SPEAKER_01]: now once you get that information

[00:33:00] [SPEAKER_01]: you may only have one or two

[00:33:02] [SPEAKER_01]: PFAS detects

[00:33:04] [SPEAKER_01]: but that's very good information

[00:33:06] [SPEAKER_01]: to know that everything else

[00:33:07] [SPEAKER_01]: maybe is not there

[00:33:08] [SPEAKER_01]: or it's in extremely low amounts

[00:33:10] [SPEAKER_01]: it will be below detection limit

[00:33:12] [SPEAKER_01]: what you can do

[00:33:13] [SPEAKER_01]: you can do all sorts of

[00:33:14] [SPEAKER_01]: graphical representations

[00:33:17] [SPEAKER_01]: with the data

[00:33:18] [SPEAKER_01]: and you typically we use pie charts

[00:33:22] [SPEAKER_01]: colored pie charts

[00:33:24] [SPEAKER_01]: that will not show the concentration

[00:33:26] [SPEAKER_01]: but will show the proportion

[00:33:28] [SPEAKER_01]: between individual PFAS compounds

[00:33:30] [SPEAKER_01]: so let's say in these samples

[00:33:32] [SPEAKER_01]: I have 10 detected PFAS

[00:33:34] [SPEAKER_01]: and then I see each pie chart

[00:33:39] [SPEAKER_01]: would be a different color

[00:33:41] [SPEAKER_01]: would represent a different detected PFAS

[00:33:44] [SPEAKER_01]: and the size of the pie chart

[00:33:46] [SPEAKER_01]: would tell me that

[00:33:47] [SPEAKER_01]: that PFAS is more prevalent

[00:33:49] [SPEAKER_01]: or less prevalent

[00:33:50] [SPEAKER_01]: than the other PFAS

[00:33:52] [SPEAKER_01]: and in forensic

[00:33:53] [SPEAKER_01]: you're really very interested in this

[00:33:56] [SPEAKER_01]: because every source

[00:33:57] [SPEAKER_01]: may provide different type of pie charts

[00:34:00] [SPEAKER_01]: you can also use radial plots

[00:34:03] [SPEAKER_01]: you can use bar charts

[00:34:06] [SPEAKER_01]: all sorts of other

[00:34:07] [SPEAKER_01]: type of graphical depiction

[00:34:10] [SPEAKER_01]: and as well you can use

[00:34:13] [SPEAKER_01]: multivariate statistical analysis

[00:34:15] [SPEAKER_01]: which try to show common features

[00:34:18] [SPEAKER_01]: between a large number of samples

[00:34:21] [SPEAKER_01]: and eliminate the basically

[00:34:24] [SPEAKER_01]: the noise that may be there

[00:34:27] [SPEAKER_01]: how do sample group

[00:34:28] [SPEAKER_01]: based on everything we know

[00:34:30] [SPEAKER_01]: all the chemical analytes

[00:34:33] [SPEAKER_01]: that we know in a sample

[00:34:35] [SPEAKER_01]: how they cluster together

[00:34:37] [SPEAKER_01]: so that you know

[00:34:38] [SPEAKER_01]: the combination of these techniques

[00:34:40] [SPEAKER_01]: can be used to look at

[00:34:43] [SPEAKER_01]: these targeted analysis data

[00:34:45] [SPEAKER_01]: and we can compare samples

[00:34:48] [SPEAKER_01]: with each other

[00:34:49] [SPEAKER_01]: as well as with known

[00:34:51] [SPEAKER_01]: or suspected sources

[00:34:52] [SPEAKER_01]: or a sample representative

[00:34:55] [SPEAKER_01]: from a suspected source

[00:34:56] [SPEAKER_01]: taken close from a release area

[00:34:59] [SPEAKER_01]: where we know it was

[00:35:00] [SPEAKER_01]: an 8FF release

[00:35:01] [SPEAKER_01]: or a spill or so on

[00:35:04] [SPEAKER_01]: but there are limitations of these things

[00:35:06] [SPEAKER_01]: I don't know

[00:35:07] [SPEAKER_01]: should I go over all the other techniques

[00:35:10] [SPEAKER_01]: or should I discuss

[00:35:11] [SPEAKER_01]: the limitations of these techniques

[00:35:13] [SPEAKER_01]: of this particular technique first?

[00:35:16] [SPEAKER_00]: Exposure science

[00:35:16] [SPEAKER_00]: covers a broad subject area

[00:35:18] [SPEAKER_00]: including toxicology

[00:35:20] [SPEAKER_00]: industrial hygiene

[00:35:21] [SPEAKER_00]: and risk assessment

[00:35:22] [SPEAKER_00]: from occupational community

[00:35:24] [SPEAKER_00]: or environmental exposure

[00:35:25] [SPEAKER_00]: exposure scientists apply

[00:35:27] [SPEAKER_00]: scientific methodologies

[00:35:29] [SPEAKER_00]: to understand exposure risks

[00:35:30] [SPEAKER_00]: and apply controls when necessary

[00:35:32] [SPEAKER_00]: we at exposure assessment consulting

[00:35:35] [SPEAKER_00]: have this expertise

[00:35:36] [SPEAKER_00]: please reach out to us

[00:35:38] [SPEAKER_00]: at info at exposureconsulting.com

[00:35:41] [SPEAKER_00]: for a free 15 minute consultation

[00:35:43] [SPEAKER_00]: to discuss the specifics

[00:35:45] [SPEAKER_00]: of your exposure scenario

[00:35:49] [SPEAKER_00]: Well go ahead

[00:35:50] [SPEAKER_00]: I think talk about the different techniques

[00:35:53] [SPEAKER_00]: let's discuss the options

[00:35:55] [SPEAKER_00]: and then say

[00:35:56] [SPEAKER_00]: this is what's available

[00:35:57] [SPEAKER_00]: and this is where you need to employ caution

[00:36:01] [SPEAKER_00]: when you're using this particular technique

[00:36:03] [SPEAKER_00]: I think that's fair

[00:36:04] [SPEAKER_01]: Okay so the main caution

[00:36:07] [SPEAKER_01]: when we use a targeted chemical analysis

[00:36:10] [SPEAKER_01]: it's really

[00:36:12] [SPEAKER_01]: we don't have a necessary a caution

[00:36:14] [SPEAKER_01]: if you're doing it

[00:36:15] [SPEAKER_01]: on a commercial lab

[00:36:16] [SPEAKER_01]: with that use a standardized DPA method

[00:36:20] [SPEAKER_01]: that is you know well qualified

[00:36:25] [SPEAKER_01]: probably you don't have to worry

[00:36:27] [SPEAKER_01]: about the quality of your data

[00:36:30] [SPEAKER_01]: of course the type of the sampling

[00:36:33] [SPEAKER_01]: you have to take particular measures

[00:36:35] [SPEAKER_01]: when you sample

[00:36:36] [SPEAKER_01]: to avoid cross-contaminations

[00:36:38] [SPEAKER_01]: and sample the right locations

[00:36:41] [SPEAKER_01]: but as long as that is done properly

[00:36:44] [SPEAKER_01]: basically it's very reliable defensible data

[00:36:47] [SPEAKER_01]: however the main limitation is that

[00:36:51] [SPEAKER_01]: well you test for 40 compounds

[00:36:54] [SPEAKER_01]: or less depending on the method you apply

[00:36:56] [SPEAKER_01]: some commercial labs

[00:36:58] [SPEAKER_01]: expand the list of compounds

[00:37:00] [SPEAKER_01]: to up to 80 to 100 individual PFAS

[00:37:04] [SPEAKER_01]: but what is 40 to 100 individual PFAS

[00:37:09] [SPEAKER_01]: compared to 10,000

[00:37:11] [SPEAKER_01]: or thousands

[00:37:13] [SPEAKER_01]: or even more PFAS compounds

[00:37:14] [SPEAKER_01]: that could be out there

[00:37:15] [SPEAKER_01]: and could be in your sample

[00:37:17] [SPEAKER_01]: so there is a lot of unknown

[00:37:21] [SPEAKER_01]: you basically target

[00:37:23] [SPEAKER_01]: all the PFAS that are regulated

[00:37:24] [SPEAKER_01]: now or may be regulated

[00:37:26] [SPEAKER_01]: as individual PFAS which is good

[00:37:29] [SPEAKER_01]: you get a lot of individual PFAS

[00:37:32] [SPEAKER_01]: now 40 it's a good number

[00:37:35] [SPEAKER_01]: you have things to work on

[00:37:38] [SPEAKER_01]: but you still are missing

[00:37:41] [SPEAKER_01]: potential other PFAS

[00:37:42] [SPEAKER_01]: and in some cases those potential other PFAS

[00:37:45] [SPEAKER_01]: I'll just give you an example

[00:37:48] [SPEAKER_01]: one of the STM methods

[00:37:51] [SPEAKER_01]: it's targeting on top of

[00:37:54] [SPEAKER_01]: the typical perfluoroalkylcarboxylates

[00:37:57] [SPEAKER_01]: and sulfonates

[00:37:58] [SPEAKER_01]: that are targeted by these methods

[00:38:00] [SPEAKER_01]: all the methods

[00:38:01] [SPEAKER_01]: all the EPA methods

[00:38:02] [SPEAKER_01]: it targets a specific type of sulfonic

[00:38:07] [SPEAKER_01]: perfluoroalkylsulfonic acids

[00:38:09] [SPEAKER_01]: which have a cyclic structure

[00:38:13] [SPEAKER_01]: and some of those are

[00:38:16] [SPEAKER_01]: what we call isobars

[00:38:17] [SPEAKER_01]: or they have the same formula

[00:38:19] [SPEAKER_01]: with some of the typical sulfonic acids

[00:38:24] [SPEAKER_01]: perfluoroalkylsulfonic acids

[00:38:25] [SPEAKER_01]: such as PFOS

[00:38:28] [SPEAKER_01]: now we see it

[00:38:29] [SPEAKER_01]: and this is a main PFAS

[00:38:31] [SPEAKER_01]: that was used in firefighting form

[00:38:32] [SPEAKER_01]: that was used in

[00:38:34] [SPEAKER_01]: had many other uses

[00:38:35] [SPEAKER_01]: and also that is regulated

[00:38:39] [SPEAKER_01]: and you know one of the

[00:38:43] [SPEAKER_01]: not just the replacement

[00:38:44] [SPEAKER_01]: it was produced in parallel with PFOS

[00:38:47] [SPEAKER_01]: is a cyclic PFAS

[00:38:49] [SPEAKER_01]: that is referred to as PFEX

[00:38:52] [SPEAKER_01]: it has a cycle of six carbons

[00:38:55] [SPEAKER_01]: in a cycle

[00:38:55] [SPEAKER_01]: and an ethyl group now

[00:38:57] [SPEAKER_01]: with two carbons linked to the cycle

[00:38:59] [SPEAKER_01]: and the sulfonic tail

[00:39:01] [SPEAKER_01]: so basically this is an

[00:39:04] [SPEAKER_01]: cyclic isomer of PFOS

[00:39:06] [SPEAKER_01]: that is not targeted

[00:39:08] [SPEAKER_01]: but by any EPA method

[00:39:10] [SPEAKER_01]: however when people are using

[00:39:12] [SPEAKER_01]: and in some states

[00:39:15] [SPEAKER_01]: they use the STM method

[00:39:17] [SPEAKER_01]: quite a lot

[00:39:21] [SPEAKER_01]: that cyclic PFAS is targeted

[00:39:23] [SPEAKER_01]: and it will be reported

[00:39:24] [SPEAKER_01]: if it is detected

[00:39:25] [SPEAKER_01]: and even if it's not detected

[00:39:27] [SPEAKER_01]: it will be reported as non-detect

[00:39:30] [SPEAKER_01]: and when that analysis is carried out

[00:39:34] [SPEAKER_01]: that PFAS is in many environments

[00:39:38] [SPEAKER_01]: as you know probably

[00:39:40] [SPEAKER_01]: it's as well spread as PFOS

[00:39:43] [SPEAKER_01]: and in some cases

[00:39:45] [SPEAKER_01]: it could be at much higher

[00:39:46] [SPEAKER_01]: concentration than PFOS

[00:39:49] [SPEAKER_01]: and we certainly miss it

[00:39:51] [SPEAKER_01]: by using the EPA methods

[00:39:52] [SPEAKER_01]: that's just one example

[00:39:55] [SPEAKER_01]: of course there could be

[00:39:56] [SPEAKER_01]: many other PFAS that potentially

[00:39:59] [SPEAKER_01]: could be problematic

[00:40:00] [SPEAKER_01]: for human health

[00:40:01] [SPEAKER_01]: could be problematic

[00:40:02] [SPEAKER_01]: for the environment

[00:40:04] [SPEAKER_01]: for the ecosystem

[00:40:05] [SPEAKER_01]: and that we are missing

[00:40:07] [SPEAKER_01]: and also by missing them

[00:40:10] [SPEAKER_01]: we are missing important

[00:40:11] [SPEAKER_01]: forensic information

[00:40:12] [SPEAKER_01]: and if a source has more

[00:40:14] [SPEAKER_01]: of the other type of PFAS

[00:40:16] [SPEAKER_01]: that we are not targeted

[00:40:18] [SPEAKER_01]: we cannot point out to that source

[00:40:21] [SPEAKER_01]: no so that's the main limitation

[00:40:23] [SPEAKER_01]: that it's a very

[00:40:25] [SPEAKER_01]: targeted analysis

[00:40:26] [SPEAKER_01]: extremely reliable

[00:40:28] [SPEAKER_01]: it is relatively inexpensive

[00:40:33] [SPEAKER_01]: and at most sites

[00:40:34] [SPEAKER_01]: you will have that type of data

[00:40:36] [SPEAKER_01]: they acquire if they study PFAS

[00:40:38] [SPEAKER_01]: they study via targeted analysis

[00:40:40] [SPEAKER_01]: so you can take advantage

[00:40:43] [SPEAKER_01]: of maybe historical data

[00:40:45] [SPEAKER_01]: in the past 10 years

[00:40:45] [SPEAKER_01]: 15 years or so

[00:40:47] [SPEAKER_01]: but you are limited

[00:40:48] [SPEAKER_01]: to the number of PFAS compounds

[00:40:52] [SPEAKER_01]: so how can we overcome

[00:40:54] [SPEAKER_01]: that limitation though

[00:40:55] [SPEAKER_01]: well that's where

[00:40:56] [SPEAKER_01]: the other techniques are coming

[00:40:57] [SPEAKER_01]: so we have three more techniques

[00:40:59] [SPEAKER_01]: that try to overcome

[00:41:00] [SPEAKER_01]: that limitation

[00:41:02] [SPEAKER_01]: of the targeted analysis

[00:41:03] [SPEAKER_01]: and the first one

[00:41:04] [SPEAKER_01]: that I want to talk about

[00:41:06] [SPEAKER_01]: because it's more used

[00:41:07] [SPEAKER_01]: it's what we refer to as TOP

[00:41:12] [SPEAKER_01]: or total oxidizable precursors

[00:41:16] [SPEAKER_01]: so now what are precursors

[00:41:17] [SPEAKER_01]: the poly PFAS are precursors

[00:41:20] [SPEAKER_01]: and they are considered precursors

[00:41:21] [SPEAKER_01]: because in the environment

[00:41:23] [SPEAKER_01]: they generate

[00:41:24] [SPEAKER_01]: the pair fluorinated PFAS

[00:41:26] [SPEAKER_01]: as we already discussed

[00:41:28] [SPEAKER_01]: now that is absolutely

[00:41:30] [SPEAKER_01]: going to happen

[00:41:31] [SPEAKER_01]: it can happen in various speeds

[00:41:34] [SPEAKER_01]: based on the environment

[00:41:35] [SPEAKER_01]: also based on the

[00:41:37] [SPEAKER_01]: that precursor PFAS

[00:41:39] [SPEAKER_01]: how easy will be

[00:41:40] [SPEAKER_01]: to break that bond

[00:41:41] [SPEAKER_01]: but it will happen

[00:41:44] [SPEAKER_01]: so we know that

[00:41:45] [SPEAKER_01]: they will not stay

[00:41:46] [SPEAKER_01]: as poly PFAS forever

[00:41:47] [SPEAKER_01]: and many of them

[00:41:49] [SPEAKER_01]: will change pretty rapidly

[00:41:51] [SPEAKER_01]: after a release

[00:41:52] [SPEAKER_01]: in such a way

[00:41:53] [SPEAKER_01]: that maybe once a release

[00:41:54] [SPEAKER_01]: gets through soil

[00:41:55] [SPEAKER_01]: and get to groundwater

[00:41:56] [SPEAKER_01]: you may find no poly PFAS at all

[00:42:00] [SPEAKER_01]: because it's all changed

[00:42:02] [SPEAKER_01]: so this total oxidizable precursor

[00:42:06] [SPEAKER_01]: is simply a targeted PFAS analysis

[00:42:09] [SPEAKER_01]: that is done twice

[00:42:11] [SPEAKER_01]: on your sample

[00:42:12] [SPEAKER_01]: initially as you typically

[00:42:13] [SPEAKER_01]: would do in a targeted

[00:42:15] [SPEAKER_01]: PFAS analysis

[00:42:16] [SPEAKER_01]: and it's also done

[00:42:18] [SPEAKER_01]: after the sample is processed

[00:42:21] [SPEAKER_01]: and it's oxidized

[00:42:23] [SPEAKER_01]: in the laboratory

[00:42:24] [SPEAKER_01]: so by oxidizing the sample

[00:42:27] [SPEAKER_01]: basically the laboratory

[00:42:28] [SPEAKER_01]: is subjecting the samples

[00:42:29] [SPEAKER_01]: to some harsh conditions

[00:42:32] [SPEAKER_01]: that will mimic

[00:42:34] [SPEAKER_01]: the environmental conditions

[00:42:36] [SPEAKER_01]: over a longer period of time

[00:42:38] [SPEAKER_01]: and will accelerate

[00:42:40] [SPEAKER_01]: the transformation

[00:42:41] [SPEAKER_01]: of any poly PFAS

[00:42:43] [SPEAKER_01]: into pair PFAS

[00:42:45] [SPEAKER_01]: in theory

[00:42:47] [SPEAKER_01]: you would expect that most

[00:42:50] [SPEAKER_01]: if not all of the poly PFAS

[00:42:52] [SPEAKER_01]: in your sample

[00:42:53] [SPEAKER_01]: to be basically transformed

[00:42:56] [SPEAKER_01]: into pair PFAS

[00:42:58] [SPEAKER_01]: by the time that the test is done

[00:43:03] [SPEAKER_01]: the second test is done

[00:43:04] [SPEAKER_01]: so you have a sample

[00:43:06] [SPEAKER_01]: the lab tested

[00:43:07] [SPEAKER_01]: before it is transformed

[00:43:09] [SPEAKER_01]: in the lab

[00:43:10] [SPEAKER_01]: and after a laboratory

[00:43:12] [SPEAKER_01]: procedures that will subject

[00:43:14] [SPEAKER_01]: that sample to high pressure

[00:43:16] [SPEAKER_01]: high temperature

[00:43:16] [SPEAKER_01]: and so on

[00:43:18] [SPEAKER_01]: maybe alkaline environment

[00:43:19] [SPEAKER_01]: and other conditions

[00:43:21] [SPEAKER_01]: in order to transform

[00:43:23] [SPEAKER_01]: those PFAS

[00:43:24] [SPEAKER_01]: and you analyze it

[00:43:27] [SPEAKER_01]: again for targeted analysis

[00:43:29] [SPEAKER_01]: so you are using a very

[00:43:33] [SPEAKER_01]: standardized

[00:43:34] [SPEAKER_01]: and reliable technique

[00:43:35] [SPEAKER_01]: which is great

[00:43:36] [SPEAKER_01]: and now you are getting

[00:43:38] [SPEAKER_01]: more information

[00:43:39] [SPEAKER_01]: if your sample has

[00:43:42] [SPEAKER_01]: poly PFAS

[00:43:43] [SPEAKER_01]: then when you analyze

[00:43:45] [SPEAKER_01]: the sample

[00:43:46] [SPEAKER_01]: after laboratory transformation

[00:43:47] [SPEAKER_01]: you're going to see

[00:43:49] [SPEAKER_01]: a distinct signature

[00:43:49] [SPEAKER_01]: you're going to see

[00:43:51] [SPEAKER_01]: more of the pair PFAS

[00:43:52] [SPEAKER_01]: that you saw before

[00:43:54] [SPEAKER_01]: and maybe less

[00:43:55] [SPEAKER_01]: of some of the poly PFAS

[00:43:57] [SPEAKER_01]: that are targeted

[00:43:59] [SPEAKER_01]: before in your sample

[00:44:03] [SPEAKER_01]: but this is great

[00:44:05] [SPEAKER_01]: this is great

[00:44:05] [SPEAKER_01]: this is a lot

[00:44:07] [SPEAKER_01]: of additional information

[00:44:08] [SPEAKER_01]: that can help you

[00:44:09] [SPEAKER_01]: that can also help you show

[00:44:10] [SPEAKER_01]: oh I have more PFAS

[00:44:13] [SPEAKER_01]: in my sample

[00:44:14] [SPEAKER_01]: and maybe in the environment

[00:44:16] [SPEAKER_01]: I can expect additional

[00:44:18] [SPEAKER_01]: regulated PFAS

[00:44:20] [SPEAKER_01]: paired PFAS

[00:44:21] [SPEAKER_01]: forever PFAS

[00:44:22] [SPEAKER_01]: to be produced

[00:44:24] [SPEAKER_01]: in my environment

[00:44:25] [SPEAKER_01]: in time

[00:44:26] [SPEAKER_01]: so you get

[00:44:29] [SPEAKER_01]: you are more aware

[00:44:30] [SPEAKER_01]: of the severity

[00:44:32] [SPEAKER_01]: of your situation

[00:44:33] [SPEAKER_01]: it also can help

[00:44:35] [SPEAKER_01]: in forensic investigation

[00:44:36] [SPEAKER_01]: because it may show

[00:44:38] [SPEAKER_01]: how your finger

[00:44:39] [SPEAKER_01]: your original fingerprint

[00:44:41] [SPEAKER_01]: may change

[00:44:41] [SPEAKER_01]: and how much

[00:44:43] [SPEAKER_01]: is that subjected to change

[00:44:44] [SPEAKER_01]: but you are bound

[00:44:47] [SPEAKER_01]: to the targeted PFAS

[00:44:48] [SPEAKER_01]: so again

[00:44:49] [SPEAKER_01]: you're missing

[00:44:50] [SPEAKER_01]: all the other PFAS

[00:44:51] [SPEAKER_01]: so you are still limited

[00:44:54] [SPEAKER_01]: to 40 PFAS

[00:44:55] [SPEAKER_01]: or 80 PFAS

[00:44:56] [SPEAKER_01]: before and after

[00:44:57] [SPEAKER_01]: that oxidation

[00:44:58] [SPEAKER_01]: so it's a good step forward

[00:45:00] [SPEAKER_01]: but it's limited

[00:45:02] [SPEAKER_01]: and the other limitation

[00:45:03] [SPEAKER_01]: of this particular technique

[00:45:05] [SPEAKER_01]: would be that

[00:45:07] [SPEAKER_01]: laboratory conditions

[00:45:09] [SPEAKER_01]: may vary in between labs

[00:45:11] [SPEAKER_01]: and because it may vary

[00:45:12] [SPEAKER_01]: and some labs

[00:45:13] [SPEAKER_01]: may generate

[00:45:15] [SPEAKER_01]: a higher degree

[00:45:16] [SPEAKER_01]: of transformation

[00:45:17] [SPEAKER_01]: than other labs

[00:45:19] [SPEAKER_01]: the final result

[00:45:20] [SPEAKER_01]: may vary

[00:45:21] [SPEAKER_01]: depending on the lab

[00:45:22] [SPEAKER_01]: you are using

[00:45:23] [SPEAKER_01]: and we saw that

[00:45:24] [SPEAKER_01]: in real data

[00:45:27] [SPEAKER_01]: but also

[00:45:28] [SPEAKER_01]: who's to say

[00:45:29] [SPEAKER_01]: is that the laboratory

[00:45:30] [SPEAKER_01]: conditions

[00:45:31] [SPEAKER_01]: would mimic

[00:45:32] [SPEAKER_01]: exactly what will happen

[00:45:33] [SPEAKER_01]: in the environment

[00:45:34] [SPEAKER_01]: no I mean

[00:45:35] [SPEAKER_01]: the idea is yes

[00:45:36] [SPEAKER_01]: these compounds

[00:45:37] [SPEAKER_01]: will transform

[00:45:38] [SPEAKER_01]: but maybe

[00:45:40] [SPEAKER_01]: in the environment

[00:45:40] [SPEAKER_01]: they may transform

[00:45:41] [SPEAKER_01]: to something else

[00:45:42] [SPEAKER_01]: maybe the proportion

[00:45:43] [SPEAKER_01]: will be different

[00:45:44] [SPEAKER_01]: maybe it will never reach

[00:45:46] [SPEAKER_01]: the proportion

[00:45:48] [SPEAKER_01]: the degree of transformation

[00:45:49] [SPEAKER_01]: you see in the lab

[00:45:50] [SPEAKER_01]: it's hard to predict

[00:45:51] [SPEAKER_01]: over how long

[00:45:53] [SPEAKER_01]: over time

[00:45:53] [SPEAKER_01]: this will happen

[00:45:55] [SPEAKER_01]: in the environment

[00:45:55] [SPEAKER_01]: so there are all sort of questions

[00:45:57] [SPEAKER_01]: so it's a big step forward

[00:45:59] [SPEAKER_01]: but we are still very limited

[00:46:01] [SPEAKER_01]: we still are dealing

[00:46:02] [SPEAKER_01]: with limited information

[00:46:03] [SPEAKER_01]: and potential confounding factors

[00:46:06] [SPEAKER_01]: so the third technique

[00:46:08] [SPEAKER_01]: that maybe

[00:46:10] [SPEAKER_01]: address some of these issues

[00:46:12] [SPEAKER_01]: is a very general technique

[00:46:15] [SPEAKER_01]: it's not a new technique

[00:46:16] [SPEAKER_01]: but it's certainly new

[00:46:17] [SPEAKER_01]: more recently applied to PFAS

[00:46:19] [SPEAKER_01]: and developed for PFAS

[00:46:21] [SPEAKER_01]: and this technique

[00:46:22] [SPEAKER_01]: it's called TOF

[00:46:24] [SPEAKER_01]: total organic fluorine

[00:46:26] [SPEAKER_01]: basically is a technique

[00:46:28] [SPEAKER_01]: it's targeting

[00:46:29] [SPEAKER_01]: the total fluorine

[00:46:32] [SPEAKER_01]: in your sample

[00:46:32] [SPEAKER_01]: that is linked

[00:46:33] [SPEAKER_01]: to an organic compound

[00:46:34] [SPEAKER_01]: so if you have an organic

[00:46:37] [SPEAKER_01]: compound in your samples

[00:46:38] [SPEAKER_01]: that has fluorine

[00:46:39] [SPEAKER_01]: you're going to get

[00:46:41] [SPEAKER_01]: the total amount

[00:46:42] [SPEAKER_01]: of all these organic compounds

[00:46:43] [SPEAKER_01]: fluorine

[00:46:45] [SPEAKER_01]: reported as fluorine

[00:46:46] [SPEAKER_01]: and then it could be translated

[00:46:47] [SPEAKER_01]: into PFAS

[00:46:49] [SPEAKER_01]: now this technique

[00:46:51] [SPEAKER_01]: it's great

[00:46:51] [SPEAKER_01]: because you are not missing

[00:46:53] [SPEAKER_01]: anything

[00:46:54] [SPEAKER_01]: but it has no specificity

[00:46:57] [SPEAKER_01]: so the other thing

[00:46:58] [SPEAKER_01]: is extremely specific

[00:47:00] [SPEAKER_01]: but you are potentially

[00:47:01] [SPEAKER_01]: missing a lot of PFAS

[00:47:03] [SPEAKER_01]: the total organic fluorine

[00:47:04] [SPEAKER_01]: it's non-specific

[00:47:06] [SPEAKER_01]: it will give you a number for

[00:47:08] [SPEAKER_01]: that could be translated

[00:47:10] [SPEAKER_01]: into total PFAS amount

[00:47:12] [SPEAKER_01]: of your sample

[00:47:13] [SPEAKER_01]: now you can be certain

[00:47:15] [SPEAKER_01]: you are not missing anything

[00:47:16] [SPEAKER_01]: and you have an idea

[00:47:18] [SPEAKER_01]: of how much

[00:47:19] [SPEAKER_01]: of a problem

[00:47:20] [SPEAKER_01]: you have at your site

[00:47:21] [SPEAKER_01]: and you know

[00:47:22] [SPEAKER_01]: how much you need to treat

[00:47:24] [SPEAKER_01]: how much can generate

[00:47:26] [SPEAKER_01]: the targeted PFAS

[00:47:27] [SPEAKER_01]: because certainly

[00:47:29] [SPEAKER_01]: when you do

[00:47:29] [SPEAKER_01]: the targeted PFAS analysis

[00:47:31] [SPEAKER_01]: and TOF

[00:47:32] [SPEAKER_01]: and you see a huge difference

[00:47:34] [SPEAKER_01]: in total PFAS

[00:47:36] [SPEAKER_01]: and I think that could be

[00:47:37] [SPEAKER_01]: order of magnitudes

[00:47:38] [SPEAKER_01]: like a thousand

[00:47:39] [SPEAKER_01]: ten thousand

[00:47:40] [SPEAKER_01]: a hundred thousand time

[00:47:41] [SPEAKER_01]: more of total organic

[00:47:43] [SPEAKER_01]: which is huge

[00:47:45] [SPEAKER_01]: then you know

[00:47:47] [SPEAKER_01]: you have a pretty

[00:47:50] [SPEAKER_01]: severe problem

[00:47:51] [SPEAKER_01]: versus if you do

[00:47:53] [SPEAKER_01]: this analysis

[00:47:53] [SPEAKER_01]: and you see a very small

[00:47:54] [SPEAKER_01]: difference

[00:47:55] [SPEAKER_01]: or no difference

[00:47:56] [SPEAKER_01]: then okay yeah

[00:47:58] [SPEAKER_01]: then it's easy

[00:48:00] [SPEAKER_01]: so that's a great advantage

[00:48:02] [SPEAKER_01]: of total organic fluorine

[00:48:03] [SPEAKER_01]: it gives you an idea

[00:48:05] [SPEAKER_01]: of what the magnitude

[00:48:06] [SPEAKER_01]: of the problem

[00:48:07] [SPEAKER_01]: but you don't know

[00:48:09] [SPEAKER_01]: what you're dealing with

[00:48:10] [SPEAKER_01]: and I would say

[00:48:12] [SPEAKER_01]: another important limitation

[00:48:13] [SPEAKER_01]: is let's go back

[00:48:16] [SPEAKER_01]: to a definition

[00:48:16] [SPEAKER_01]: what is a PFAS

[00:48:18] [SPEAKER_01]: now the technique looks at

[00:48:20] [SPEAKER_01]: every thing

[00:48:21] [SPEAKER_01]: any organic compound

[00:48:22] [SPEAKER_01]: with a carbon and fluorine

[00:48:24] [SPEAKER_01]: will contribute

[00:48:25] [SPEAKER_01]: to the result

[00:48:27] [SPEAKER_01]: but there are organic compounds

[00:48:29] [SPEAKER_01]: and those are

[00:48:31] [SPEAKER_01]: a good example

[00:48:32] [SPEAKER_01]: would be pharmaceuticals

[00:48:34] [SPEAKER_01]: and some of the

[00:48:35] [SPEAKER_01]: pharmaceuticals

[00:48:36] [SPEAKER_01]: are very common

[00:48:37] [SPEAKER_01]: I think Prozac is one of them

[00:48:39] [SPEAKER_01]: there are few others

[00:48:40] [SPEAKER_01]: I can provide a list

[00:48:42] [SPEAKER_01]: or maybe a link

[00:48:43] [SPEAKER_01]: where people can find

[00:48:44] [SPEAKER_01]: more information

[00:48:45] [SPEAKER_01]: they have carbon and fluorine

[00:48:47] [SPEAKER_01]: and they're fluorinated

[00:48:49] [SPEAKER_01]: organic compounds

[00:48:51] [SPEAKER_01]: so in a wastewater

[00:48:52] [SPEAKER_01]: that has pharmaceutical waste

[00:48:55] [SPEAKER_01]: you're going to have those too

[00:48:57] [SPEAKER_01]: so who's to say

[00:48:59] [SPEAKER_01]: though maybe half of your

[00:49:01] [SPEAKER_01]: total organic fluorine

[00:49:02] [SPEAKER_01]: or so on

[00:49:03] [SPEAKER_01]: of course it could be

[00:49:04] [SPEAKER_01]: case by case

[00:49:05] [SPEAKER_01]: so we have to keep in mind

[00:49:07] [SPEAKER_01]: it's not only

[00:49:08] [SPEAKER_01]: we don't know

[00:49:09] [SPEAKER_01]: which exact PFAS

[00:49:10] [SPEAKER_01]: are giving us

[00:49:12] [SPEAKER_01]: these total PFAS

[00:49:13] [SPEAKER_01]: concentrations

[00:49:14] [SPEAKER_01]: but also

[00:49:15] [SPEAKER_01]: there could be

[00:49:16] [SPEAKER_01]: non-PFAS compounds

[00:49:18] [SPEAKER_01]: that will contribute

[00:49:21] [SPEAKER_01]: to the total result

[00:49:23] [SPEAKER_01]: and will exacerbate

[00:49:25] [SPEAKER_01]: if you like the problem

[00:49:28] [SPEAKER_01]: but another

[00:49:30] [SPEAKER_01]: I haven't talked

[00:49:31] [SPEAKER_01]: forensically speaking

[00:49:33] [SPEAKER_01]: TOF

[00:49:34] [SPEAKER_01]: it's also a useful technique

[00:49:37] [SPEAKER_01]: for example

[00:49:38] [SPEAKER_01]: I saw a paper

[00:49:39] [SPEAKER_01]: where they look at

[00:49:40] [SPEAKER_01]: A triple Fs

[00:49:41] [SPEAKER_01]: different type of A triple Fs

[00:49:43] [SPEAKER_01]: and they look at

[00:49:44] [SPEAKER_01]: total organic fluorine

[00:49:45] [SPEAKER_01]: in those A triple Fs

[00:49:47] [SPEAKER_01]: and it was different

[00:49:48] [SPEAKER_01]: in concentration

[00:49:49] [SPEAKER_01]: so at least originally

[00:49:52] [SPEAKER_01]: we have different

[00:49:53] [SPEAKER_01]: total PFAS concentrations

[00:49:55] [SPEAKER_01]: in different A triple F

[00:49:57] [SPEAKER_01]: forms

[00:49:57] [SPEAKER_01]: and that could be

[00:49:59] [SPEAKER_01]: an additional line

[00:50:00] [SPEAKER_01]: of evidence

[00:50:00] [SPEAKER_01]: an additional fingerprint

[00:50:02] [SPEAKER_01]: then maybe we can use

[00:50:03] [SPEAKER_01]: when we have multiple

[00:50:05] [SPEAKER_01]: A triple F sources

[00:50:07] [SPEAKER_01]: so it has forensic values

[00:50:09] [SPEAKER_01]: it certainly has

[00:50:11] [SPEAKER_01]: values for evaluating

[00:50:13] [SPEAKER_01]: the risk

[00:50:13] [SPEAKER_01]: maybe the toxicological risk

[00:50:16] [SPEAKER_01]: and so on

[00:50:17] [SPEAKER_01]: even on a general

[00:50:18] [SPEAKER_01]: or large scale

[00:50:19] [SPEAKER_01]: or the magnitude of risk

[00:50:21] [SPEAKER_01]: if you like

[00:50:21] [SPEAKER_01]: if not specific

[00:50:23] [SPEAKER_01]: and it really

[00:50:26] [SPEAKER_01]: address a problem

[00:50:27] [SPEAKER_01]: of all the PFAS

[00:50:29] [SPEAKER_01]: is probably

[00:50:30] [SPEAKER_01]: more inclusive

[00:50:31] [SPEAKER_01]: than it should be

[00:50:32] [SPEAKER_01]: and the last technique

[00:50:33] [SPEAKER_01]: I want to point out

[00:50:35] [SPEAKER_01]: which is

[00:50:37] [SPEAKER_01]: the most specific technique

[00:50:38] [SPEAKER_01]: and when I see

[00:50:39] [SPEAKER_01]: the Eurofemes webinars

[00:50:40] [SPEAKER_01]: on this technique

[00:50:41] [SPEAKER_01]: it's really

[00:50:44] [SPEAKER_01]: I like the slides

[00:50:45] [SPEAKER_01]: they are using

[00:50:46] [SPEAKER_01]: when introducing this technique

[00:50:47] [SPEAKER_01]: and they show

[00:50:48] [SPEAKER_01]: a very luxurious sports car

[00:50:51] [SPEAKER_01]: so maybe Toyota,

[00:50:53] [SPEAKER_01]: Honda

[00:50:55] [SPEAKER_01]: these type of common cars

[00:50:56] [SPEAKER_01]: would be your

[00:50:58] [SPEAKER_01]: the standard EPA methods

[00:51:01] [SPEAKER_01]: that are looking

[00:51:02] [SPEAKER_01]: at targeted PFAS compounds

[00:51:03] [SPEAKER_01]: and your Lamborghini

[00:51:07] [SPEAKER_01]: would be this method

[00:51:08] [SPEAKER_01]: which is of course

[00:51:09] [SPEAKER_01]: as Lamar is very expensive

[00:51:12] [SPEAKER_01]: but if you extremely

[00:51:15] [SPEAKER_01]: useful data

[00:51:16] [SPEAKER_01]: particularly in forensic

[00:51:17] [SPEAKER_01]: investigation

[00:51:18] [SPEAKER_01]: because this technique

[00:51:20] [SPEAKER_01]: refers to non-targeted

[00:51:22] [SPEAKER_01]: PFAS compounds

[00:51:23] [SPEAKER_01]: and those are PFAS compounds

[00:51:25] [SPEAKER_01]: that we don't have

[00:51:27] [SPEAKER_01]: a standard for

[00:51:28] [SPEAKER_01]: that are not tested

[00:51:30] [SPEAKER_01]: by any other technique

[00:51:32] [SPEAKER_01]: and sometimes

[00:51:34] [SPEAKER_01]: or many times

[00:51:36] [SPEAKER_01]: we may not even know

[00:51:38] [SPEAKER_01]: what is their structure

[00:51:40] [SPEAKER_01]: but we know they are there

[00:51:45] [SPEAKER_01]: and you know

[00:51:46] [SPEAKER_01]: this is still

[00:51:47] [SPEAKER_01]: a liquid chromatography technique

[00:51:49] [SPEAKER_01]: as a standard analysis

[00:51:50] [SPEAKER_01]: but a standard analysis

[00:51:52] [SPEAKER_01]: has a liquid chromatography

[00:51:53] [SPEAKER_01]: linked to a mass spectrometry

[00:51:55] [SPEAKER_01]: this is linked

[00:51:56] [SPEAKER_01]: to a particular mass spectrometer

[00:52:00] [SPEAKER_01]: that is much more accurate

[00:52:02] [SPEAKER_01]: the time of flight

[00:52:03] [SPEAKER_01]: quadruple mass spectrometry

[00:52:05] [SPEAKER_01]: and that provides

[00:52:07] [SPEAKER_01]: extremely accurate information

[00:52:08] [SPEAKER_01]: without having standards

[00:52:10] [SPEAKER_01]: so just based on the

[00:52:13] [SPEAKER_01]: chemical behavior

[00:52:14] [SPEAKER_01]: carbon and fluorine

[00:52:15] [SPEAKER_01]: it's supposed segments

[00:52:16] [SPEAKER_01]: are supposed to behave

[00:52:17] [SPEAKER_01]: a certain way

[00:52:18] [SPEAKER_01]: and elute from your column

[00:52:21] [SPEAKER_01]: at a certain time

[00:52:22] [SPEAKER_01]: and if you get those hits

[00:52:25] [SPEAKER_01]: which are not related

[00:52:27] [SPEAKER_01]: to any of the standard PFAS

[00:52:29] [SPEAKER_01]: you still know you have

[00:52:30] [SPEAKER_01]: you are dealing with a PFAS compound

[00:52:32] [SPEAKER_01]: and sometimes

[00:52:33] [SPEAKER_01]: there are libraries

[00:52:35] [SPEAKER_01]: more inclusive libraries

[00:52:36] [SPEAKER_01]: that you can compare

[00:52:37] [SPEAKER_01]: the structure

[00:52:38] [SPEAKER_01]: and you can deduce

[00:52:39] [SPEAKER_01]: what exact structure

[00:52:41] [SPEAKER_01]: that compound has

[00:52:42] [SPEAKER_01]: and you have a cast number

[00:52:44] [SPEAKER_01]: and you have a name

[00:52:45] [SPEAKER_01]: for that compound

[00:52:46] [SPEAKER_01]: sometimes you may not be able

[00:52:47] [SPEAKER_01]: to do that

[00:52:48] [SPEAKER_01]: but forensically

[00:52:49] [SPEAKER_01]: it's still important information

[00:52:51] [SPEAKER_01]: because you compare sample

[00:52:52] [SPEAKER_01]: between them

[00:52:53] [SPEAKER_01]: and with sources

[00:52:55] [SPEAKER_01]: or suspected sources

[00:52:56] [SPEAKER_01]: so that is an expensive technique

[00:53:00] [SPEAKER_01]: I wouldn't say it's less reliable

[00:53:02] [SPEAKER_01]: but it's less used

[00:53:03] [SPEAKER_01]: so potentially it may be

[00:53:06] [SPEAKER_01]: challenging in the court of law

[00:53:08] [SPEAKER_01]: more than the other techniques

[00:53:10] [SPEAKER_01]: but I think as an independent

[00:53:12] [SPEAKER_01]: line of evidence

[00:53:13] [SPEAKER_01]: along with other techniques

[00:53:16] [SPEAKER_01]: it could be very useful

[00:53:18] [SPEAKER_01]: rather than just used by itself

[00:53:20] [SPEAKER_01]: and the last thing

[00:53:21] [SPEAKER_01]: I want to point out

[00:53:23] [SPEAKER_01]: is that the regulators

[00:53:25] [SPEAKER_01]: and regulatory agencies

[00:53:28] [SPEAKER_01]: are more and more

[00:53:30] [SPEAKER_01]: inclined

[00:53:32] [SPEAKER_01]: to use these non-conventional

[00:53:34] [SPEAKER_01]: PFAS techniques

[00:53:36] [SPEAKER_01]: and it's not just

[00:53:38] [SPEAKER_01]: total organic fluorine

[00:53:40] [SPEAKER_01]: which is used

[00:53:41] [SPEAKER_01]: by many or is required to be used

[00:53:44] [SPEAKER_01]: but also the non-target analysis

[00:53:46] [SPEAKER_01]: and that's how for example

[00:53:49] [SPEAKER_01]: I saw a paper

[00:53:50] [SPEAKER_01]: I can make it available

[00:53:53] [SPEAKER_01]: in I think it was in New Jersey

[00:53:55] [SPEAKER_01]: at the location

[00:53:56] [SPEAKER_01]: where there were two chemical

[00:53:57] [SPEAKER_01]: manufacturers of PFAS

[00:54:00] [SPEAKER_01]: and I see it was Solvay and Chemur

[00:54:05] [SPEAKER_01]: and they use this

[00:54:07] [SPEAKER_01]: EPA used non-target analysis

[00:54:09] [SPEAKER_01]: and they did find a class of PFAS

[00:54:13] [SPEAKER_01]: that was not known before

[00:54:15] [SPEAKER_01]: and was associated to one of these sources

[00:54:17] [SPEAKER_01]: and not with the other

[00:54:18] [SPEAKER_01]: and that's how they were able

[00:54:21] [SPEAKER_01]: to distinguish what was coming

[00:54:23] [SPEAKER_01]: from one source versus the other

[00:54:25] [SPEAKER_01]: very interesting and clearly

[00:54:28] [SPEAKER_01]: practical applications

[00:54:31] [SPEAKER_01]: and also in California

[00:54:32] [SPEAKER_01]: I think in some poor communities

[00:54:38] [SPEAKER_01]: small utilities, water utilities

[00:54:42] [SPEAKER_01]: they conduct a study

[00:54:45] [SPEAKER_01]: using these two techniques

[00:54:46] [SPEAKER_01]: TOF and the non-target analysis

[00:54:49] [SPEAKER_01]: and they compare the data

[00:54:51] [SPEAKER_01]: with the targeted analysis

[00:54:52] [SPEAKER_01]: they found huge discrepancy

[00:54:55] [SPEAKER_01]: like you know

[00:54:56] [SPEAKER_01]: targeted analysis was not able to capture

[00:54:58] [SPEAKER_01]: more than half or even less

[00:55:00] [SPEAKER_01]: of the PFAS that were out there

[00:55:02] [SPEAKER_01]: and based on that

[00:55:03] [SPEAKER_01]: I think California Water Board

[00:55:06] [SPEAKER_01]: recently announced a secure funds

[00:55:08] [SPEAKER_01]: to apply these non-conventional

[00:55:10] [SPEAKER_01]: PFAS techniques

[00:55:12] [SPEAKER_01]: to a larger amount of water utilities

[00:55:15] [SPEAKER_01]: so you know

[00:55:16] [SPEAKER_01]: I think it's coming

[00:55:17] [SPEAKER_01]: and not just in the forensic realm

[00:55:20] [SPEAKER_00]: Now that's interesting

[00:55:22] [SPEAKER_00]: You gave lots of interesting information there

[00:55:25] [SPEAKER_00]: I appreciate it

[00:55:25] [SPEAKER_00]: You kind of touched on the subjects

[00:55:28] [SPEAKER_00]: about you know the method challenges

[00:55:30] [SPEAKER_00]: and overcoming analytical techniques

[00:55:32] [SPEAKER_00]: a couple of things

[00:55:33] [SPEAKER_00]: I wanted to ask you about

[00:55:34] [SPEAKER_00]: and you could probably address them

[00:55:35] [SPEAKER_00]: and you just kind of even talked

[00:55:37] [SPEAKER_00]: about there about two different facilities

[00:55:39] [SPEAKER_00]: that had a commingling

[00:55:41] [SPEAKER_00]: of release materials

[00:55:42] [SPEAKER_00]: You know you talked about states

[00:55:45] [SPEAKER_00]: and you talked about EPA

[00:55:46] [SPEAKER_00]: and federal methods

[00:55:49] [SPEAKER_00]: and you talked about interlab variability

[00:55:52] [SPEAKER_00]: You know how do you mesh all that together

[00:55:55] [SPEAKER_00]: when states may be using ASTM methods

[00:55:58] [SPEAKER_00]: versus federal that's using EPA

[00:55:59] [SPEAKER_00]: and then you have different labs

[00:56:01] [SPEAKER_00]: that may have different internal

[00:56:03] [SPEAKER_00]: I'll say SOPs

[00:56:06] [SPEAKER_00]: reporting liniments or what have you

[00:56:07] [SPEAKER_00]: How are you able to

[00:56:10] [SPEAKER_00]: more accurately or better

[00:56:13] [SPEAKER_00]: kind of look at the data

[00:56:15] [SPEAKER_00]: that is produced from these evaluations

[00:56:17] [SPEAKER_00]: and help it to assist

[00:56:20] [SPEAKER_00]: in other identification

[00:56:23] [SPEAKER_00]: or differentiation

[00:56:25] [SPEAKER_00]: and delineation

[00:56:26] [SPEAKER_00]: for site contamination issues

[00:56:29] [SPEAKER_00]: How can you mesh all that together

[00:56:32] [SPEAKER_00]: with so many I'll say

[00:56:34] [SPEAKER_00]: other variable factors

[00:56:37] [SPEAKER_01]: No, that's a good point

[00:56:39] [SPEAKER_01]: I would say specificity is a key

[00:56:41] [SPEAKER_01]: specificity

[00:56:42] [SPEAKER_01]: When you're talking about PFAS

[00:56:44] [SPEAKER_01]: highly specific

[00:56:45] [SPEAKER_01]: There is not silver bullet

[00:56:47] [SPEAKER_01]: There is not one measure for all

[00:56:50] [SPEAKER_01]: Ideally you would want the same lab

[00:56:53] [SPEAKER_01]: to have handled and tested your samples

[00:56:56] [SPEAKER_01]: across the years

[00:56:57] [SPEAKER_01]: in a forensic investigation

[00:56:59] [SPEAKER_01]: Ideally

[00:56:59] [SPEAKER_01]: However, I would not be much concerned

[00:57:02] [SPEAKER_01]: with a standard EPA method

[00:57:04] [SPEAKER_01]: Now before the method 1633

[00:57:07] [SPEAKER_01]: was available like a couple of years ago

[00:57:11] [SPEAKER_01]: In order to analyze environmental samples

[00:57:14] [SPEAKER_01]: Laborato

[00:57:15] [SPEAKER_01]: It was really like the Wild West out there

[00:57:17] [SPEAKER_01]: You know

[00:57:19] [SPEAKER_01]: Laboratories were using

[00:57:22] [SPEAKER_01]: the drinking water technique 537.1

[00:57:26] [SPEAKER_01]: and just modify that technique

[00:57:28] [SPEAKER_01]: And that was the only way to do it

[00:57:30] [SPEAKER_01]: I mean it's not the laboratory's fault

[00:57:32] [SPEAKER_01]: I mean they

[00:57:33] [SPEAKER_01]: That was the only way to handle

[00:57:35] [SPEAKER_01]: the data

[00:57:35] [SPEAKER_01]: and to report the data

[00:57:36] [SPEAKER_01]: There was no EPA standard method available

[00:57:39] [SPEAKER_01]: And in that situation

[00:57:41] [SPEAKER_01]: So if your data comes prior to 2021

[00:57:44] [SPEAKER_01]: I would say or so

[00:57:46] [SPEAKER_01]: Then you have to check the lab sheets

[00:57:49] [SPEAKER_01]: discuss with the lab

[00:57:51] [SPEAKER_01]: The type of modification

[00:57:52] [SPEAKER_01]: If different labs analyze your sample at a site

[00:57:57] [SPEAKER_01]: In order to

[00:57:59] [SPEAKER_01]: When you want to compare the data

[00:58:00] [SPEAKER_01]: Make sure you understand

[00:58:02] [SPEAKER_01]: How the labs modified that technique

[00:58:06] [SPEAKER_01]: When they sample

[00:58:08] [SPEAKER_01]: When they analyze your sample

[00:58:10] [SPEAKER_01]: How did they handle the samples

[00:58:13] [SPEAKER_01]: And if you don't see any specific differences

[00:58:17] [SPEAKER_01]: Then you should be good to go

[00:58:18] [SPEAKER_01]: If there are differences

[00:58:20] [SPEAKER_01]: Then probably you need to consult a chemist

[00:58:22] [SPEAKER_01]: and make sure those differences

[00:58:24] [SPEAKER_01]: Would not affect or bias the final result

[00:58:27] [SPEAKER_01]: So it's all case by case

[00:58:29] [SPEAKER_01]: The standard methods

[00:58:31] [SPEAKER_01]: Right now I think are pretty good

[00:58:34] [SPEAKER_01]: And the best way to do it

[00:58:36] [SPEAKER_01]: Is get a well-established commercial lab

[00:58:38] [SPEAKER_01]: That has

[00:58:41] [SPEAKER_01]: That is certified

[00:58:42] [SPEAKER_01]: You know

[00:58:42] [SPEAKER_01]: They could be certified by states

[00:58:44] [SPEAKER_01]: They could be EPA certified

[00:58:46] [SPEAKER_01]: And then you can't go wrong

[00:58:47] [SPEAKER_01]: I don't think so

[00:58:50] [SPEAKER_00]: Sure and then you kind of

[00:58:52] [SPEAKER_00]: Brought up a good point there

[00:58:55] [SPEAKER_00]: Of having the certified laboratory

[00:58:59] [SPEAKER_00]: And typically I have seen this a few times

[00:59:02] [SPEAKER_00]: And I'll get you to kind of give your thoughts on it too

[00:59:04] [SPEAKER_00]: You know in recent years

[00:59:05] [SPEAKER_00]: There have been a lot of environmental labs

[00:59:08] [SPEAKER_00]: I see it from the exposure side

[00:59:09] [SPEAKER_00]: And the environmental side

[00:59:10] [SPEAKER_00]: That have been acquired by larger labs

[00:59:13] [SPEAKER_00]: They become under the umbrella of other ones

[00:59:15] [SPEAKER_00]: And they have to operate differently

[00:59:17] [SPEAKER_00]: Have you seen any issues with

[00:59:19] [SPEAKER_00]: The acquisition of any laboratories

[00:59:21] [SPEAKER_00]: And transformation of what they were to now

[00:59:24] [SPEAKER_00]: As compared to the data analysis

[00:59:26] [SPEAKER_00]: Or methods that they may have used back then

[00:59:28] [SPEAKER_00]: To what they are currently using

[00:59:30] [SPEAKER_00]: Based on what is required by them

[00:59:31] [SPEAKER_00]: By the overall new lab that they are

[00:59:35] [SPEAKER_01]: Yes well that's a good point

[00:59:37] [SPEAKER_01]: I personally cannot think of any particular example

[00:59:42] [SPEAKER_01]: I know that there is a trend in environmental industry

[00:59:46] [SPEAKER_01]: And environmental commercial lab industry

[00:59:49] [SPEAKER_01]: To say so to that large laboratories

[00:59:52] [SPEAKER_01]: Have acquired in recent years

[00:59:55] [SPEAKER_01]: Many smaller laboratories

[00:59:57] [SPEAKER_01]: I cannot think of a particular issue

[00:59:59] [SPEAKER_01]: I don't think it will be an issue

[01:00:01] [SPEAKER_01]: And even the same lab

[01:00:04] [SPEAKER_01]: I think it's possible over the years

[01:00:06] [SPEAKER_01]: To change the ways they modify a method

[01:00:08] [SPEAKER_01]: So just the fact that it's the same lab

[01:00:11] [SPEAKER_01]: Does not 100% sure that the same modifications were done

[01:00:17] [SPEAKER_01]: Or the same exactly same procedures were done

[01:00:19] [SPEAKER_01]: Across the years

[01:00:20] [SPEAKER_01]: So it's always good to check, to double check

[01:00:24] [SPEAKER_00]: That's fair

[01:00:25] [SPEAKER_00]: Yeah

[01:00:26] [SPEAKER_00]: And one thing I like that you said

[01:00:29] [SPEAKER_00]: I'll ask you to talk about this a little more

[01:00:31] [SPEAKER_00]: Is and I always talk about it in what I do

[01:00:34] [SPEAKER_00]: Is there is not a one size fits all scenario

[01:00:37] [SPEAKER_00]: It's going to be very specific for your scenario

[01:00:40] [SPEAKER_00]: I've seen a lot of people say

[01:00:41] [SPEAKER_00]: Well, I've seen this

[01:00:43] [SPEAKER_00]: And this is the way they do it here

[01:00:44] [SPEAKER_00]: I just might as well do it the same way

[01:00:46] [SPEAKER_00]: And can you kind of discuss the necessity

[01:00:49] [SPEAKER_00]: Of having an individualized assessment of the scenario

[01:00:53] [SPEAKER_00]: Or the site or contamination issue

[01:00:55] [SPEAKER_00]: Because just because they seem similar on the surface

[01:00:59] [SPEAKER_00]: Doesn't mean underneath the surface they are going to be

[01:01:03] [SPEAKER_01]: Yes, what you mentioned

[01:01:05] [SPEAKER_01]: It's absolutely right for any contaminants

[01:01:08] [SPEAKER_01]: That's ideal

[01:01:09] [SPEAKER_01]: You want to have a site-specific approach

[01:01:11] [SPEAKER_01]: But this is absolutely critical for PFAS

[01:01:15] [SPEAKER_01]: And the main reason would be

[01:01:16] [SPEAKER_01]: Because PFAS are unlike any other contaminants

[01:01:20] [SPEAKER_01]: In the fact that we have all these polyfluorinated PFAS

[01:01:25] [SPEAKER_01]: That will eventually transform into perfluorinated PFAS

[01:01:30] [SPEAKER_01]: So now you may be understanding your source maybe

[01:01:35] [SPEAKER_01]: And you can look in the literature related to

[01:01:38] [SPEAKER_01]: The source that you're having

[01:01:40] [SPEAKER_01]: Maybe it has been reported

[01:01:42] [SPEAKER_01]: It has been analyzed

[01:01:43] [SPEAKER_01]: You understand it

[01:01:44] [SPEAKER_01]: But every environment is different

[01:01:47] [SPEAKER_01]: And you need to make sure that

[01:01:51] [SPEAKER_01]: Whatever data you are using from the literature

[01:01:54] [SPEAKER_01]: For example, people are providing information

[01:01:57] [SPEAKER_01]: On the transformation PFAS

[01:02:00] [SPEAKER_01]: Coming from various individual polyPFAS

[01:02:03] [SPEAKER_01]: And you can find that information

[01:02:05] [SPEAKER_01]: I had presented it in several of my presentations

[01:02:09] [SPEAKER_01]: And it's useful in general

[01:02:11] [SPEAKER_01]: But is it applicable for your site conditions

[01:02:14] [SPEAKER_01]: Because all these transformations are done in the lab

[01:02:17] [SPEAKER_01]: So keep an eye on that

[01:02:20] [SPEAKER_01]: Secondly, there is this cross-contamination issue

[01:02:25] [SPEAKER_01]: And I discuss in some of my past presentations

[01:02:28] [SPEAKER_01]: I'm still learning about it myself

[01:02:30] [SPEAKER_01]: And when we talk about cross-contamination

[01:02:32] [SPEAKER_01]: People think of sampling

[01:02:34] [SPEAKER_01]: There could be cross-contamination when you sample

[01:02:37] [SPEAKER_01]: But in general it's not a big issue

[01:02:39] [SPEAKER_01]: And it is easily captured by using QC data

[01:02:45] [SPEAKER_01]: And field blanks and equipment blanks and so on

[01:02:48] [SPEAKER_01]: However, when we are dealing with

[01:02:51] [SPEAKER_01]: For example, storage material

[01:02:53] [SPEAKER_01]: Transport and storage

[01:02:55] [SPEAKER_01]: Particularly storage for AFFFs

[01:02:57] [SPEAKER_01]: Let's assume a company has used legacy AFFF

[01:03:02] [SPEAKER_01]: For a long time

[01:03:04] [SPEAKER_01]: And at some point they switched to modern AFFF

[01:03:08] [SPEAKER_01]: And they did not particularly change or clean

[01:03:12] [SPEAKER_01]: Their equipment and their storage

[01:03:15] [SPEAKER_01]: There could be enough left

[01:03:18] [SPEAKER_01]: In the specific storage container

[01:03:20] [SPEAKER_01]: Drum, whatever it is

[01:03:22] [SPEAKER_01]: Tank to contaminate the modern AFFF

[01:03:27] [SPEAKER_01]: And when the modern AFFF is building the environment

[01:03:29] [SPEAKER_01]: It may retain the signature of a legacy AFFF

[01:03:33] [SPEAKER_01]: And if you're not carefully checking the exact source

[01:03:37] [SPEAKER_01]: Get a sample from that tank that was built

[01:03:41] [SPEAKER_01]: Then you may miss it

[01:03:42] [SPEAKER_01]: And it was reported

[01:03:43] [SPEAKER_01]: You don't have time

[01:03:45] [SPEAKER_01]: Maybe we do another podcast on this

[01:03:48] [SPEAKER_01]: It was reported in various locations

[01:03:52] [SPEAKER_01]: It may happen

[01:03:53] [SPEAKER_01]: And it may hugely influence the fingerprint you get

[01:03:56] [SPEAKER_01]: Another scenario would be

[01:03:59] [SPEAKER_01]: You have a modern AFFF that's built at an airport

[01:04:02] [SPEAKER_01]: And this happened in real life

[01:04:04] [SPEAKER_01]: And the regulatory body requires you to clean to a certain level

[01:04:11] [SPEAKER_01]: You clean to a certain level

[01:04:12] [SPEAKER_01]: You check the PFAFs that are regulated

[01:04:15] [SPEAKER_01]: Carboxylate, sulfurase to a certain level

[01:04:17] [SPEAKER_01]: And that's fine

[01:04:20] [SPEAKER_01]: But if you don't check, for example

[01:04:25] [SPEAKER_01]: Certain PFAFs

[01:04:28] [SPEAKER_01]: It's because they are not regulated

[01:04:29] [SPEAKER_01]: Or maybe because you don't expect them to be in modern AFFF

[01:04:33] [SPEAKER_01]: Such as sulfonates

[01:04:35] [SPEAKER_01]: They still may be there

[01:04:36] [SPEAKER_01]: And they may be there due to cross-contamination

[01:04:39] [SPEAKER_01]: Or maybe it could be an older release

[01:04:40] [SPEAKER_01]: That you are encountering in deeper soil

[01:04:43] [SPEAKER_01]: So there are extremely many confounding issues with PFAFs

[01:04:49] [SPEAKER_01]: You have to be very specific

[01:04:51] [SPEAKER_01]: You have to understand

[01:04:52] [SPEAKER_01]: And even like talking to people who handle PFAFs

[01:04:56] [SPEAKER_01]: What happened

[01:04:58] [SPEAKER_01]: Try to get a sample that's representative for really what was built

[01:05:02] [SPEAKER_01]: Rather than assume that what was built had a certain fingerprint

[01:05:07] [SPEAKER_01]: Or a certain composition

[01:05:09] [SPEAKER_01]: And take into account all the scenarios

[01:05:12] [SPEAKER_01]: And I would end with like

[01:05:14] [SPEAKER_01]: My company I'm right now consulting with Unsafe

[01:05:18] [SPEAKER_01]: And we have a strong PFAS team that is looking at PFAS

[01:05:23] [SPEAKER_01]: But regardless of contaminants

[01:05:25] [SPEAKER_01]: I really like that my company always have this

[01:05:29] [SPEAKER_01]: I would say T3 approach

[01:05:33] [SPEAKER_01]: Like SYNC SYNC through

[01:05:35] [SPEAKER_01]: And I think it goes for any aspect of life

[01:05:38] [SPEAKER_01]: Any aspect of environmental investigations

[01:05:41] [SPEAKER_01]: And it is critical for PFAS

[01:05:45] [SPEAKER_01]: SYNC SYNC through sampling, analysis

[01:05:49] [SPEAKER_01]: And what you do with the data

[01:05:53] [SPEAKER_00]: I think that's great

[01:05:55] [SPEAKER_00]: And I always tell people

[01:05:58] [SPEAKER_00]: Individuals like yourself are the experts in this

[01:06:01] [SPEAKER_00]: In what you're doing

[01:06:01] [SPEAKER_00]: And it's important to go out there

[01:06:04] [SPEAKER_00]: And have you on the ground

[01:06:06] [SPEAKER_00]: Talking to people

[01:06:07] [SPEAKER_00]: Understanding the scenario

[01:06:09] [SPEAKER_00]: Sometimes people say

[01:06:10] [SPEAKER_00]: Well do you really need to come out and do a side inspection

[01:06:13] [SPEAKER_00]: Can't we just tell you what's going on

[01:06:15] [SPEAKER_00]: And that is not helpful

[01:06:16] [SPEAKER_00]: That only gets me bits and pieces of the information

[01:06:19] [SPEAKER_00]: I'm going to be missing things

[01:06:20] [SPEAKER_00]: I think it's critical that people like yourself

[01:06:23] [SPEAKER_00]: Are able to go out and evaluate

[01:06:26] [SPEAKER_00]: And you say think things through

[01:06:28] [SPEAKER_00]: Know everything

[01:06:29] [SPEAKER_00]: Identify it

[01:06:30] [SPEAKER_00]: Especially if you're under some kind of regulatory review

[01:06:35] [SPEAKER_00]: From an EP or otherwise

[01:06:38] [SPEAKER_00]: You're up against something

[01:06:39] [SPEAKER_00]: Where they have something that says

[01:06:41] [SPEAKER_00]: You have to clean up to this level

[01:06:42] [SPEAKER_00]: You need to understand

[01:06:43] [SPEAKER_00]: Is it rational to clean to this level

[01:06:46] [SPEAKER_00]: Is it physically feasible to clean to this level

[01:06:48] [SPEAKER_00]: It has to be all thought through

[01:06:50] [SPEAKER_00]: And I think you put it great the way you did

[01:06:52] [SPEAKER_00]: So based on kind of what we've discussed today

[01:06:57] [SPEAKER_00]: Identifying the PFAS

[01:06:58] [SPEAKER_00]: And the way to identify them in the environment

[01:07:00] [SPEAKER_00]: Can you kind of give us a synopsis

[01:07:02] [SPEAKER_00]: Of what your thoughts overall are

[01:07:04] [SPEAKER_00]: From the environmental contamination identification issue

[01:07:08] [SPEAKER_00]: And kind of also kind of discuss

[01:07:11] [SPEAKER_00]: What can people do to

[01:07:13] [SPEAKER_00]: The prevalence of the material

[01:07:15] [SPEAKER_00]: What can people do to reduce their risk

[01:07:18] [SPEAKER_01]: Yes, no, that's great

[01:07:20] [SPEAKER_01]: That's a good point

[01:07:22] [SPEAKER_01]: Well, I think first of all

[01:07:24] [SPEAKER_01]: PFAS are very different

[01:07:25] [SPEAKER_01]: We haven't seen them before

[01:07:27] [SPEAKER_01]: If something was working with other contaminants

[01:07:29] [SPEAKER_01]: So from an environmental perspective

[01:07:31] [SPEAKER_01]: It doesn't mean it will work with PFAS

[01:07:34] [SPEAKER_01]: They are so different from everything we have seen

[01:07:37] [SPEAKER_01]: If sampling is not a big deal

[01:07:39] [SPEAKER_01]: With other contaminants

[01:07:40] [SPEAKER_01]: It could be a huge deal with PFAS

[01:07:43] [SPEAKER_01]: And again, that could be a subject by itself to discuss

[01:07:46] [SPEAKER_01]: How can you very well miss hot spots of PFAS

[01:07:49] [SPEAKER_01]: Just by sampling

[01:07:50] [SPEAKER_01]: And not considering specific properties

[01:07:54] [SPEAKER_01]: That PFAS have and that accumulation

[01:07:57] [SPEAKER_01]: And interfaces and so on

[01:07:59] [SPEAKER_01]: So that is very, very, very important

[01:08:04] [SPEAKER_01]: With PFAS

[01:08:05] [SPEAKER_01]: Again, I said specificity

[01:08:07] [SPEAKER_01]: I would say

[01:08:11] [SPEAKER_01]: The first time when we see compounds regulated

[01:08:15] [SPEAKER_01]: Potentially regulated as a class

[01:08:17] [SPEAKER_01]: And eliminated as a class

[01:08:19] [SPEAKER_01]: I would say these anthropogenic compounds

[01:08:23] [SPEAKER_01]: Because they are not produced in nature

[01:08:26] [SPEAKER_01]: Have background values such as metals

[01:08:28] [SPEAKER_01]: When we're dealing with heavy metals

[01:08:30] [SPEAKER_01]: We have to understand the background

[01:08:32] [SPEAKER_01]: Because they are everywhere

[01:08:33] [SPEAKER_01]: And they come from rocks

[01:08:35] [SPEAKER_01]: As far as I know

[01:08:37] [SPEAKER_01]: There is not a general issue of background values

[01:08:40] [SPEAKER_01]: For a chlorinated solvent

[01:08:42] [SPEAKER_01]: Or a petroleum product

[01:08:46] [SPEAKER_01]: So PFAS

[01:08:47] [SPEAKER_01]: When we're dealing with investigating PFAS

[01:08:49] [SPEAKER_01]: First of all, do not assume they are similar

[01:08:51] [SPEAKER_01]: With everything else you have seen

[01:08:53] [SPEAKER_01]: So be prepared for the unexpected

[01:08:56] [SPEAKER_01]: Be very specific

[01:08:58] [SPEAKER_01]: Define the background of the environment

[01:09:01] [SPEAKER_01]: Because right now they are in every environment

[01:09:03] [SPEAKER_01]: We have to understand what's the background

[01:09:05] [SPEAKER_01]: And you cannot clean below that background

[01:09:08] [SPEAKER_01]: It does not make sense

[01:09:10] [SPEAKER_01]: Also, the risk should be evaluated

[01:09:14] [SPEAKER_01]: On a case-by-case basis

[01:09:16] [SPEAKER_01]: As toxicologists you may know better

[01:09:19] [SPEAKER_01]: Be very specific

[01:09:22] [SPEAKER_01]: We see the trends

[01:09:23] [SPEAKER_01]: It's not like

[01:09:24] [SPEAKER_01]: My PFAS ISO companies

[01:09:26] [SPEAKER_01]: Consider that their PFAS is okay

[01:09:30] [SPEAKER_01]: Maybe they have some studies

[01:09:31] [SPEAKER_01]: Or maybe it's so different

[01:09:33] [SPEAKER_01]: From everything we know

[01:09:34] [SPEAKER_01]: That it probably will never be analyzed for

[01:09:39] [SPEAKER_01]: Well, there will always be

[01:09:41] [SPEAKER_01]: We see this approach

[01:09:43] [SPEAKER_01]: That PFAS would be

[01:09:46] [SPEAKER_01]: Regulated as a class

[01:09:48] [SPEAKER_01]: And you may be responsible and litigated

[01:09:51] [SPEAKER_01]: For having that PFAS

[01:09:52] [SPEAKER_01]: That is so unusual

[01:09:53] [SPEAKER_01]: That will never show up in any test

[01:09:55] [SPEAKER_01]: Except total organic fluoride

[01:09:57] [SPEAKER_01]: So as a company

[01:09:59] [SPEAKER_01]: Never assume that

[01:10:01] [SPEAKER_01]: Because it's secret

[01:10:03] [SPEAKER_01]: Nobody would know

[01:10:04] [SPEAKER_01]: And this PFAS is fine

[01:10:05] [SPEAKER_01]: It's different from everything else

[01:10:07] [SPEAKER_01]: Not be analyzed

[01:10:08] [SPEAKER_01]: Well, EPA can always come and analyze

[01:10:10] [SPEAKER_01]: And find what it is

[01:10:11] [SPEAKER_01]: But also it could be regulated as a class

[01:10:14] [SPEAKER_01]: So that's what I see

[01:10:15] [SPEAKER_01]: I think stay away from PFAS from now on

[01:10:18] [SPEAKER_01]: For the company

[01:10:19] [SPEAKER_01]: It's a big deal

[01:10:20] [SPEAKER_01]: It's not easy

[01:10:21] [SPEAKER_01]: But that's a message

[01:10:23] [SPEAKER_01]: And for environmental people

[01:10:24] [SPEAKER_01]: Be specific

[01:10:26] [SPEAKER_01]: Understand and learn every day

[01:10:28] [SPEAKER_01]: It's something that we keep learning

[01:10:30] [SPEAKER_01]: We keep being better

[01:10:32] [SPEAKER_01]: Be open to things

[01:10:34] [SPEAKER_01]: That may not be the way they are

[01:10:37] [SPEAKER_01]: I work at so many military sites

[01:10:39] [SPEAKER_01]: Some people may say

[01:10:40] [SPEAKER_01]: I work at so many airports

[01:10:42] [SPEAKER_01]: I'm an expert

[01:10:43] [SPEAKER_01]: I know

[01:10:43] [SPEAKER_01]: Well, it might be different in this case

[01:10:45] [SPEAKER_01]: Because maybe you have another source

[01:10:48] [SPEAKER_01]: On top of what you have

[01:10:50] [SPEAKER_01]: Because maybe you don't have that petroleum association

[01:10:52] [SPEAKER_01]: Maybe you have a chlorine solvent

[01:10:54] [SPEAKER_01]: That comes there

[01:10:55] [SPEAKER_01]: Maybe your site has been treated differently

[01:10:58] [SPEAKER_01]: And the way it's treated for other contaminants

[01:11:00] [SPEAKER_01]: May influence PFAS fate and transport

[01:11:02] [SPEAKER_01]: So it has to be very specific

[01:11:04] [SPEAKER_01]: Now as a person that

[01:11:07] [SPEAKER_01]: I suppose I have PFAS

[01:11:09] [SPEAKER_01]: I have to take measures

[01:11:11] [SPEAKER_01]: For an everyday person

[01:11:14] [SPEAKER_01]: That wants to try to reduce the exposure to PFAS

[01:11:19] [SPEAKER_01]: I think there are a few obvious things

[01:11:21] [SPEAKER_01]: That people can do

[01:11:23] [SPEAKER_01]: But they're obvious to me

[01:11:24] [SPEAKER_01]: They are not obvious to everybody

[01:11:26] [SPEAKER_01]: So I would say first

[01:11:27] [SPEAKER_01]: Start with filtering your water

[01:11:29] [SPEAKER_01]: Get a water filter

[01:11:30] [SPEAKER_01]: Even the can that

[01:11:33] [SPEAKER_01]: You found at Walmart

[01:11:35] [SPEAKER_01]: Could be very good

[01:11:36] [SPEAKER_01]: Because they have these carbon filters

[01:11:38] [SPEAKER_01]: Maybe not the best

[01:11:39] [SPEAKER_01]: But you don't even have to install anything on your sink

[01:11:43] [SPEAKER_01]: Just get that water filter

[01:11:45] [SPEAKER_01]: And filter your water

[01:11:47] [SPEAKER_01]: They are fast

[01:11:47] [SPEAKER_01]: They are cheap

[01:11:49] [SPEAKER_01]: And you never know

[01:11:51] [SPEAKER_01]: Maybe your water utility has not detected PFAS so far

[01:11:55] [SPEAKER_01]: But it might get detected a month from now

[01:11:58] [SPEAKER_01]: Or a year from now

[01:11:59] [SPEAKER_01]: And so on

[01:12:00] [SPEAKER_01]: So you want to be very cautious

[01:12:03] [SPEAKER_01]: Don't eat popcorn

[01:12:05] [SPEAKER_01]: Don't eat microwave popcorn

[01:12:07] [SPEAKER_01]: I used to eat

[01:12:08] [SPEAKER_01]: I love popcorn

[01:12:09] [SPEAKER_01]: I did not eat it too often

[01:12:12] [SPEAKER_01]: Maybe once a week or so

[01:12:13] [SPEAKER_01]: I treated myself with a microwave popcorn

[01:12:15] [SPEAKER_01]: But I didn't know

[01:12:16] [SPEAKER_01]: Now I know

[01:12:17] [SPEAKER_01]: I stay away

[01:12:18] [SPEAKER_01]: So microwavable popcorn

[01:12:20] [SPEAKER_01]: They have PFAS in them

[01:12:22] [SPEAKER_01]: Obviously that popcorn is subjected

[01:12:24] [SPEAKER_01]: That you know the paper

[01:12:25] [SPEAKER_01]: They're in the paper

[01:12:27] [SPEAKER_01]: You cook them in a paper

[01:12:28] [SPEAKER_01]: It's subjected to high heat

[01:12:30] [SPEAKER_01]: So stay away from that

[01:12:33] [SPEAKER_01]: I would say get an air filter

[01:12:35] [SPEAKER_01]: That is always good for any type of contaminants

[01:12:39] [SPEAKER_01]: Some PFAS are volatile

[01:12:41] [SPEAKER_01]: They are in the air

[01:12:42] [SPEAKER_01]: Some are just in the air particles

[01:12:43] [SPEAKER_01]: In particular matter

[01:12:45] [SPEAKER_01]: Having an air filter in your house

[01:12:47] [SPEAKER_01]: It's a very good way

[01:12:49] [SPEAKER_01]: Try to minimize

[01:12:50] [SPEAKER_01]: I would say outdoor equipment

[01:12:52] [SPEAKER_01]: That's fine

[01:12:53] [SPEAKER_01]: You don't go outdoor every day

[01:12:54] [SPEAKER_01]: Unless you

[01:12:55] [SPEAKER_01]: If you go every day

[01:12:56] [SPEAKER_01]: Try not to wear waterproof things

[01:12:59] [SPEAKER_01]: Get as little as possible

[01:13:01] [SPEAKER_01]: Don't wash them all the time

[01:13:03] [SPEAKER_01]: Because that's a way

[01:13:04] [SPEAKER_01]: That PFAS may go into the environment

[01:13:08] [SPEAKER_01]: And particularly cosmetics

[01:13:10] [SPEAKER_01]: Being a woman

[01:13:11] [SPEAKER_01]: We all like creams and cosmetics

[01:13:13] [SPEAKER_01]: Stay away from anything that's waterproof

[01:13:15] [SPEAKER_01]: No, we don't need waterproof mascara

[01:13:18] [SPEAKER_01]: Everything may still have some PFAS in them

[01:13:20] [SPEAKER_01]: But the waterproof are almost guaranteed

[01:13:23] [SPEAKER_01]: They will have PFAS

[01:13:25] [SPEAKER_01]: And any common sense approach

[01:13:29] [SPEAKER_01]: Try to inform yourself

[01:13:30] [SPEAKER_01]: For example, Google alerts are very good

[01:13:33] [SPEAKER_01]: If you put a Google alert on PFAS

[01:13:36] [SPEAKER_01]: On your email

[01:13:37] [SPEAKER_01]: You may get useful information

[01:13:39] [SPEAKER_01]: What's new?

[01:13:40] [SPEAKER_01]: What's out there?

[01:13:41] [SPEAKER_01]: Apple news could be very good

[01:13:42] [SPEAKER_01]: Just keep informed

[01:13:44] [SPEAKER_01]: I learn every day

[01:13:45] [SPEAKER_01]: So I guess that's my message

[01:13:48] [SPEAKER_01]: There could be many other small things

[01:13:50] [SPEAKER_01]: But for the most part

[01:13:52] [SPEAKER_01]: That's how you stay away from PFAS

[01:13:54] [SPEAKER_01]: As much as you can

[01:13:57] [SPEAKER_00]: Awesome

[01:13:58] [SPEAKER_00]: Thank you very much

[01:13:59] [SPEAKER_00]: Dr. Iwanda Petros-Shour

[01:14:00] [SPEAKER_00]: Thank you so much for joining us today

[01:14:02] [SPEAKER_00]: We greatly appreciate your insight

[01:14:04] [SPEAKER_00]: And expertise on this matter

[01:14:06] [SPEAKER_00]: So thank you

[01:14:08] [SPEAKER_01]: Oh, I appreciate the invitation

[01:14:10] [SPEAKER_01]: I'm always happy to talk

[01:14:12] [SPEAKER_01]: And who knows

[01:14:14] [SPEAKER_01]: Maybe we'll have some interesting news

[01:14:17] [SPEAKER_01]: In the future

[01:14:17] [SPEAKER_01]: I'll keep you posted

[01:14:18] [SPEAKER_01]: I want to learn from toxicologists like you

[01:14:22] [SPEAKER_01]: Because it's all a matter of

[01:14:25] [SPEAKER_01]: Multidisciplinary approach

[01:14:27] [SPEAKER_00]: Awesome

[01:14:28] [SPEAKER_00]: We'd love to have you back

[01:14:29] [SPEAKER_00]: Thank you so much

[01:14:30] [SPEAKER_01]: All right

[01:14:31] [SPEAKER_01]: Well, thank you

[01:14:32] [SPEAKER_00]: Thank you for listening to the

[01:14:34] [SPEAKER_00]: Exposure Scientist podcast

[01:14:36] [SPEAKER_00]: You can connect with us at our website

[01:14:39] [SPEAKER_00]: exposureconsulting.com

[01:14:40] [SPEAKER_00]: Where you can book a private consultation

[01:14:42] [SPEAKER_00]: And send in any questions

[01:14:43] [SPEAKER_00]: Regarding any episodes

[01:14:44] [SPEAKER_00]: Or our guests

[01:14:46] [SPEAKER_00]: See you on the next episode