Tom Huang – ENVMAT

45% of U.S. Drinking Water Has PFAS — My Thoughts

Tom Huang — Sat, 28 Oct 2023 23:40:55 +0000

I saw an interesting paper about PFAS published last August and wanted to write about my thoughts. In a comprehensive study of tap water by the United States Geological Survey (USGS) containing 716 sites, it was found that 45% of tap water locations in the U.S. contain PFAS. The three most common PFAS found were PFBS, PFHxS, and PFOA.

Something that stood out to me immediately was the presence of PFBS, PFHxS, and PFOA in 15% of the samples. PFBS and PFHxS are what are known as short-chain PFASs, which I’ve talked about in previous blog posts. In short, these chemicals were introduced by chemical companies like DuPont to dodge regulatory suspicion from the government. However, these chemicals have also demonstrated the potential to cause the same negative health effects associated with long-chain PFAS. To me, the presence of short-chain PFAS in drinking water supplies indicates that not enough is likely being done to control PFAS pollution. Short-chain PFAS have only been an alternative to long-chain PFAS for about 15 years, but they have already begun to replace long-chain PFAS in the environment.

The differences in specific PFAS between water sources are also intriguing to me. About a year ago, I sent a sample of tap water from my own house to a certified lab for liquid chromatography-mass spectrometry (LC-MS) testing. The only detected PFAS was PFOA, which was present at 1.9ng/L. This experience really made me understand how much of a nightmare it is for the EPA to figure out a national standard for PFAS, especially when water sources across the U.S. can contain so great a variety of PFAS that may not all cause the same negative health effects. Based on these conclusions, I think that it’ll definitely be a while before we see enforceable national limits on PFAS.

My PFAS testing results

Sources
USGS Paper

Eliminating PFAS from Used GAC Water Filters

Tom Huang — Tue, 30 Aug 2022 02:22:48 +0000

As part of a greater government push for scientific funding of PFAS research, many projects have captured my interest. I’m here to share one of them with you today. Recently, the National Science Foundation (NSF) has awarded $250K to Dr. Onur Apul, assistant professor of environmental engineering from the University of Maine, to study how to remove PFAS from used GAC filters.

Granular activated carbon (GAC) water filters are one of the most reliable ways to remove PFAS from drinking water sources. I’ve covered this topic in previous blog posts (here’s a recent example). Once GAC filters are spent, they are usually discarded or incinerated. Both disposal options for GAC are detrimental, because they cause environmental pollution. In previous blog posts, we have discussed how PFAS tend to be extremely resistant to breaking down in the environment. Once in a landfill, PFAS will eventually find their way into the environment, contributing to human exposure. Incinerating PFAS will cause it to leak into the air.

Dr. Apul and his team hope to identify factors that lead to PFAS breakdown, which will be useful in mitigating environmental PFAS release from used filters. Additionally, if successful, Dr. Apul’s research on PFAS breakdown could be expanded to other PFAS-laden objects that are commonly discarded in landfills or incinerated, such as food packaging and other consumer waste.

GAC filters are used in water treatment plants and household plumbing to reduce, if not completely mitigate, PFAS concentrations in water at the point of entry (source)

Mitigating the release of environmental PFAS is a crucial step that can immediately lessen the effect of PFAS exposure on human populations. Although research into PFAS may be time-consuming and not conclusive, actions taken to reduce environmental PFAS concentrations is a step in the right direction.

Click here for more info

MA Firefighters Sue 3M and DuPont

Tom Huang — Tue, 30 Aug 2022 01:58:49 +0000

In February 2022, firefighters from towns throughout Massachusetts, including Worcester and Boston, sued chemical companies 3M and DuPont. The 15 firefighters allege that these chemical companies have manufactured PFAS-containing products for firefighting use that, unbeknownst to firefighters, expose them to negative health effects.

All of the firefighters mentioned in the lawsuit developed cancer, with most developing prostate cancer. According to the International Association of Fire Fighters, America’s largest firefighting union, cancer is the leading cause of death for firefighters, which is consistent with PFAS’ links to cancer.

As mentioned in a previous three-blog series covering how the public found out about PFAS, DuPont and 3M are major industrial manufacturers of PFAS. They have manufactured PFAS for a variety of uses, including non-stick applications. Because PFAS has high temperature and chemical strength, they are consistently found in firefighting gear.

PFAS is a major component of aqueous film-forming films (AFFFs). Although most fire departments have discontinued their use of AFFFs, residual PFAS may still reside on the surface of firefighting gear.

Firefighters, in training and actual firefighting, have encountered PFAS from the foam they use and their equipment (source)

While reading the suit, I noticed that the document drew upon findings previously exposed in Rob Bilott’s lawsuit against 3M and DuPont(see earlier links). It’s interesting and fitting how such a landmark case has provided a precedent and framework upon which people inflicted with health complications from PFAS can punish chemical companies which have directly led to their exposure. Of all industries other than those that directly work with PFAS manufacturing, firefighting most urgently needs workplace regulations to keep these brave people safe.

Sources
Boston.com
WGBH.org

Household PFAS Treatment

Tom Huang — Mon, 08 Aug 2022 18:41:54 +0000

As the PFAS issue becomes more prevalent in national news, an increasing amounts of homeowners want to mitigate the threat of PFAS in their water supply. Even though fluorocarbons have many different forms, there are general PFAS solutions for drinking water that exist for the average homeowner. I’ll go over which viable solutions exist, and then I’ll write about my thoughts.

State governments commonly recommend two kinds of water treatment systems: granular activated carbon (GAC) filters and reverse osmosis (RO). According to the New Hampshire Department of Environmental Sciences (NHDES), GAC is better suited for treating water at the point of entry (POE), which is the point where the water main connects to the house. The NHDES recommends this specific placement of GAC because, while the filter system can remove a significant amount of PFAS, it cannot filter out other contaminants. Therefore, RO is better applied at the point of use (POU), which is the point where water is accessed by humans for use.

Water filter system containing a GAC filter (source)

Reverse Osmosis Tank (source)

Even though GAC filters may seem inferior, a recent study (published in 2020) by Duke University found that cheap GAC dual-stage POU filters may be more effective at removing PFAS from residential water. Dual-stage filters and RO were able to remove, on average, more than 90% of PFAS from POU, while other GAC filters were less effective and had varied results.

The previously mentioned systems may not always remove all PFAS from water. In order to eliminate PFAS from a household’s water supply, a custom, comprehensive system of filters is required. The NHDES says that a water system containing the following has “proven to be effective at removing PFAS to non-detectable levels in New Hampshire and other New England states.”:

Five-micron particulate filter for pre-filtering;
Two GAC treatment vessels (two cubic feet each) in series with a test port installed after the lead treatment unit (the exact size and number of carbon vessels required depends on flow rate and flow volume associated with the home);
Five-micron particulate filter for post-filtering;
Totalizer meter;
Ultra-violet treatment system and associated controllers if untreated water from the well exhibits bacteria contamination;

Such a system would look like this! (source)

In my opinion, whether it is feasible to implement household PFAS mitigation systems all depends on cost. On Amazon, an RO POU system costs around $200, and various small household GAC systems cost $100 or more. The comprehensive filter system I mentioned earlier is difficult to price, but taking into account how household GAC filters can exceed $1000, the total price would be no lower than $2000. In addition to these PFAS treatment systems, there are water testing costs. Each lab test for a single water source will cost around $250. At the bare minimum, $500 dollars will be spent on testing, because a homeowner would need to know two things: whether their water contains detectable amounts of PFAS and whether the installed PFAS mitigation system was effective.

Sources:
NHDES website
Duke University PFAS study

EPA National Testing Strategy

Tom Huang — Wed, 03 Aug 2022 00:46:34 +0000

In October 2021, the EPA developed a new national testing strategy for PFAS that attempts to bypass some difficulties in screening for the thousands of PFAS in the environment. The EPA is now adopting a strategy of categorizing PFAS according to chemical structure and toxicity. In categorizing PFAS, EPA hopes to select a few specific PFAS that are representative of all PFAS, which allows sample testing to provide more substantive information. In this post, I’ll unpack how EPA proposes doing so.

Flowchart of EPA initial selection process for PFAS (source)

The EPA has a large database of chemicals called DSSTox, which provides extensive chemical-related data on over 800,000 compounds. From DSSTox, EPA has applied structural filters to weed out all chemicals that generally cannot be classified as PFAS. From there, EPA applies “primary structural categories,” which divide the selected PFAS into specific categories depending on chemical structure. After that, each primary category is divided into secondary categories that classify PFAS based on length. In literature, the length of PFAS have shown to affect how long they spend in the human body, in addition to adverse health effects.

Flowchart of EPA final selection process for PFAS (source)

When the PFAS has been categorized by structure, the EPA then applies filters based on whether a specific chemical has toxicity data and is industrially prevalent. On its initial selection run, the EPA selected 24 PFAS candidates that were representative of the numerous PFAS categories.

I believe that the categorization of PFAS based on structure and toxicity is a step in the right direction. Currently, official EPA drinking water testing methods analyze for ~30 PFAS, which were picked based on their industrial prevalence. In selecting specific PFAS candidates, EPA testing methods can be improved to provide more information about all PFAS in a sample, not just a select few.

Furthermore, I think that systematically categorizing PFAS by a central authority has implications beyond sample testing. If this standard of PFAS grouping is established in academia, the health effects of PFAS can be more extensively studied. In addition, adopting standards by which PFAS can be categorized will prevent chemical companies from avoiding regulations by inventing new PFAS.

For more information, check out this link.

My Opinion on the New EPA PFAS Advisory Limits

Tom Huang — Mon, 01 Aug 2022 20:47:48 +0000

Hello, blog! It’s been a while since I last posted, and I apologize for my absence. In these past six months, a few notable events have happened with PFAS, the most notable of which is the new EPA advisory limits.

On June 15th, 2022, the US Environmental Protection Agency (EPA) released new drinking water advisory limits for four specific PFAS: PFOA (0.004 parts per trillion), PFOS (0.02 parts per trillion), GenX (10 parts per trillion), and PFBS (2,000 parts per trillion). The previous 2016 advisory limits encompassed PFOA and PFOS only, limiting the sum of their concentrations in drinking water to 70 ppt. Thus, these new advisory limits are up to 17,000 times more sensitive than before. The two new PFAS, GenX and PFBS, are modern industrial alternatives to PFOA and PFOS. For the first time, the EPA is taking newer PFAS into account, and warning against their consumption. Additionally, the EPA has introduced $1 billion dollars of grant funding as part of President Biden’s Bipartisan Infrastructure Law to mitigate the impact of PFAS on a state level.

In my opinion, the EPA’s vastly more sensitive advisory limits can be seen as controversial. The EPA’s new advisory limits are thousands of times lower below the detection limits of current PFAS testing methods. The rationale behind the EPA’s decision making is that, in reality, no amount of PFAS is safe for drinking water consumption. All things considered, how are people supposed to know if their drinking water is safe for consumption if they can’t even measure its PFAS concentration down to regulatory limits? It’s contradictory to what a concentration limit should be. Additionally, publishing such a limit undermines drinking water testing in states without PFAS regulations. In the absence of an enforceable, national PFAS limit for drinking water, what standard are Americans to rely on in order to check whether their water is safe? Initially, 70 ppt was a very testable limit to check the safety of drinking water. Now, you can’t even tell whether your water is safe or not.

Nevertheless, I am excited that the EPA has taken action to target newer PFAS that pose equally serious risks to our health. The EPA is planning on proposing a national PFAS drinking water regulatory limit in Fall 2022. I look forward to hearing about where the regulatory limit lies, since the EPA has declared that no amount is safe.

Overall, I am ecstatic that a governmental effort to protect the public from PFAS is underway. With the PFAS Action Act of 2021 pending review by the Senate, we are close to reaching a status quo where PFAS is not a massive health concern to all Americans.

Find out more here: https://www.epa.gov/newsreleases/epa-announces-new-drinking-water-health-advisories-pfas-chemicals-1-billion-bipartisan

Tutorial: How to collect home samples for EPA Method 537!

Tom Huang — Mon, 31 Jan 2022 03:01:34 +0000

Last Monday (January 22, 2024), I collected water samples for LC-MS lab tests as part of my PFAS detection method research. Two (drinking water) of my five samples are to be processed through EPA Method 537.

Today, having performed multiple sample collections, I would like to walk my readers through the process of collecting water samples for EPA Method 537 with photographs.

Before collecting any samples, please make sure you have the following from the laboratory analyzing your samples:

Two sealed HDPE PFAS sample containers with TRIZMA preservative inside. Some laboratories may have fewer bottles, and may provide two more bottles. I will explain this in the procedure down below.

I spilled one of these last Monday… luckily I had a spare! Make sure to be careful not to spill the contents of the sample bottles; you only have one bottle most of the time.

Chain-of-custody form

A chain-of-custody form has pricing on it because it’s basically the initial documentation before testing can start.

Powder-free nitrile gloves

Make sure they aren’t vinyl or latex gloves!!!

A cooler filled with ice

I had gas station ice layered on top of ice packs in a cooler.

With these items gathered, we can now start preparing to take our sample.
Make sure:

You are wearing powderless nitrile gloves
- Do NOT use latex or vinyl gloves
You have not handled any aerosolized perfumes, detergents, or insect repellents before sampling
You have not touched any food packaging before sampling

Time to start the procedure!

Put gloves on. Label your sample bottles with your initials, time and date of collection, and sample name.

I did the time after sample collection to be more accurate. It’s unnecessary, though.

Run your cold tap for three minutes.

Three minutes pass excruciatingly slowly when you watch water run.

After three minutes, narrow the water flow down until you can see through it.

No bubbles are visible!

Open sample bottle and fill to its neck.

Don’t drop it!

The neck of the bottle is indicated here.

Close the cap, and shake a couple times to mix the preservative.

The preservative should disappear pretty quickly.

Depending on the laboratory, you may have more samples bottles to fill. Additionally, some laboratories may provide you a bottle filled with laboratory water and an empty bottle for the purpose of collecting a control sample. If you have extra sample bottles, repeat steps 4 and 5. If you have a laboratory water bottle, simply pour the water into the empty bottle and discard the now-empty bottle.

Place your sample bottles and control (if applicable) into your cooler.

Make sure the bottles are upright when you place them in.

Return your samples to the lab and you’re done!

I hope that this guide was helpful and instructive. If you have any questions, don’t hesitate to contact me at tomtomboy2011@gmail.com.

For more detailed instructions, visit this website.

PFAS in Food?

Tom Huang — Sun, 02 Jan 2022 23:48:34 +0000

PFAS has multiple pathways into the human body, including food, water, breathing, and (rarely) skin contact. Originating from the industrial manufacturing sector and our environment by proxy, PFASs have found their way into our bodies, mainly through food and water that have been contaminated in a variety of ways.

Diagram of PFAS pathways (Source: “A review of the pathways of human exposure to poly-and perfluoroalkyl substances (PFASs) and present understanding of
health effects” Sunderland, 2018)

PFAS pollution is directly related to our dietary intake. PFASs in the environment find their way into animals and plants, where they persist long enough to enter our bodies via consumption. PFASs can also find their way into our bodies from food packaging itself. Because PFASs are valued for their stain-resistant nature, they have seen extensive use in disposable food containers. According to FDA studies, using PFAS-contaminated soil, water, or biosolids to grow food can also cause food contamination. Currently, it is difficult to concretely connect PFAS contamination levels to adverse health effects (that is, it is difficult to ascertain what level of PFAS will cause what effects), so the FDA uses the most up-to-date scientific literature to estimate hazards.

Just like for water, the FDA has created a liquid chromatography-mass spectrometry (LC-MS) method for 16 types of PFAS in food (specifically bread, lettuce, milk, and fish), called C-010.01. The FDA has reported that this method can detect PFAS in food from 7 to 901 parts per trillion, which is very suitable for detection levels of all kinds in food. C-010.01 is apparently commercially available, but I could not find any laboratories that advertised PFAS testing for food when researching online.

Sources
https://www.fda.gov/food/chemical-contaminants-food/testing-food-pfas-and-assessing-dietary-exposure
https://supplychain.edf.org/resources/testing-for-pfas-in-food/

PFAS End of Year Recap – the current situation

Tom Huang — Thu, 30 Dec 2021 22:20:49 +0000

This year, PFAS has experienced a monumental rise in media coverage and public attention. Due to the PFAS-conscious policies of the Massachusetts Department of Environmental Protection (MassDEP) requiring PFAS testing, many towns found dangerous PFAS levels in their water sources. By May, around 20% of tested public wells contained above-regulation PFAS levels.

Communities scrambled to find ways to address their PFAS problem. Wayland, MA, resorted to handing out bottled water (with a cost of $20,000 per week) to its residents as a temporary water supply, while other towns like Wellesley fell back on their connections to the MWRA (Massachusetts Watershed Resource Association). Two major ways towns are considering dealing with this problem on the long-term side of things are either through connecting water pipes to the MWRA or installing their own expensive GAC (granular activated carbon) filters, both of which are highly expensive options that are expected to take a heavy toll on town budgets.

GAC filter (source)

The financial situation and problems of towns across Massachusetts bring to awareness a problem towards the establishment of federal regulations: not every town has the financial and logistical resources to comply with regulations. Solving the PFAS issue will require millions of dollars in financial aid to provide safe drinking water to the American people.

In the new year, I hope that more progress will be made in removing this toxic chemical from water supplies so that Americans will no longer face dreadful health effects. We need the government to intervene and put forth policies of regulation on a federal scale, so PFAS pollution can be greatly reduced and managed.

Happy New Year to All!

Sources
https://www.bostonglobe.com/2021/05/23/science/more-communities-are-finding-toxic-chemicals-their-drinking-water/

Hanscom AFB – A Potential Source of PFAS in Massachusetts?

Tom Huang — Thu, 30 Dec 2021 01:08:48 +0000

Hanscom Air Force Base is an Air Force base located in Bedford, Massachusetts, and is the headquarters for the Massachusetts National Guard. Hanscom AFB also hosts non-military activities, including firefighting training that may use aqueous film-forming foams (AFFFs), which have been mentioned earlier to contain PFAS [1].

Entrance to Hanscom AFB (source)

To summarize what has been presented in previous posts, Air Force bases are commonly a source of PFAS pollution, because they host firefighting training that uses AFFFs, a type of firefighting agent that ends up seeping into the ground and polluting groundwater. [2]

Because governments do not understand where PFAS comes from, especially in environments hundreds of miles away from chemical plants, it is important that we investigate where PFAS can potentially come from.

From personal investigation, it seems that Hanscom AFB could be a major source of PFAS pollution in Massachusetts, aside from chemical manufacturing factories. PFAS levels near military facilities can reach micrograms per liter, which are a thousand times above safe levels. Further worrying is the lack of evidence surrounding PFAS pollution in Hanscom AFB, especially when they may use AFFFs. Their 2020 Water Quality Report does not feature coverage of PFAS [3].

If PFAS pollution is not being investigated around Hanscom, even if they have phased out the use of AFFFs, then it poses a serious risk to the health of people in New England. It is a horrible oversight to ignore a major potential source of so-called “forever chemicals” that are increasingly being perceived as a threat to public health.

Sources
[1] https://www.hanscom.af.mil/News/Photos/igphoto/2002734894/
[2] https://www.mass.gov/info-details/per-and-polyfluoroalkyl-substances-pfas
[3] https://www.hanscom.af.mil/News/Article-Display/Article/2676576/2020-annual-drinking-water-quality-report/