Seemingly everywhere you look there are articles on the dangers of PFAS. Federal and state governments, environmental groups, and the media have declared that dangerous PFAS chemicals are everywhere and present a widespread problem across the U.S. The condemnation and fearmongering are so widespread that you’d be forgiven if you question why we would even bother to write about such a black-and-white subject in the first place. But we must.
One of our society’s great challenges is understanding and determining what is fact, what is hype, and what is simply not true. I am writing about PFAS because this is a textbook example of when misinformation gets repeated enough times, it becomes mistaken for the truth, which fails to serve the public.
As I discussed in a previous article PFAS is the acronym for per - and polyfluoroalkyl substances, a large group of approximately 4,700 chemicals. In 2001 a class-action lawsuit was filed against DuPont Corporation for releasing perfluorooctanoic acid (PFOA), a PFAS used in the manufacturing of Teflon, into the environment. Although DuPont eliminated all PFOA and PFOA-related chemicals by 2015, these chemicals, which are difficult to break down, are still found at very low levels in the environment, including drinking water. Other PFAS chemicals were developed as safer replacements and are in use today; they are being lumped together with PFOA as dangerous to public health.
What is Happening?
In 2019, the EPA issued an action plan to address PFAS. Several of the items on the action plan make sense, including issuing Health Advisories (non-enforceable health goals) and regulations for PFAS found in drinking water.
However, one of the items on the action plan deserves special consideration due to its significance. The EPA stated its intent to classify PFAS as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), known generically as the “Superfund Law .”The first step in the regulatory process was carried out in January 2021, with EPA issuing an Advanced Notice of Proposed Rulemaking (ANPRM).
Under CERCLA, the EPA has the authority to respond to releases into the environment of any hazardous substance “which may present an imminent and substantial danger to the public health and welfare,” including substances that are listed or designated under other environmental laws, such as the Clean Air Act or Clean Water Acts.
EPA has never attempted to list substances as hazardous that were not listed under other environmental laws. The EPA stated in the ANPRM that its authority to do this for PFAS lies in its interpretation of “may present” in the law, indicating that Congress did not require certainty that the substance presents a substantial danger or proof of actual harm.
Thus, according to the EPA, there does not need to be any actual proof that a substance causes harm before being designated as a hazardous substance; there only needs to be proof that it may cause harm. In giving itself the authority to regulate all chemicals whether they cause harm or not, the EPA appears to create a significant regulatory expansion of administrative authority. Many feel there is no statutory basis for the EPA to consider substances “hazardous” without proof of any real harm. For example, since any substance can cause harm at a high enough dose, every chemical we use could be added to the hazardous substance list. This regulatory expansion will likely be subject to legal challenges.
Once a substance is designated as hazardous, it has widespread repercussions across the U.S. economy. The ANPRM listed 23 individual PFAS chemicals considered hazardous substances under this proposal and 16 industrial sectors that would be affected, including aviation, car washes, cleaning product manufacturers, municipal fire departments, and landfills.
Articles have appeared across the country, such as this one from Michigan talking about alarming levels of PFAS found in beef or a recent article in Consumer Reports reporting on levels of PFAS in different types of food packing, including fast-food chains like Burger King and McDonald’s. Additionally, several states and municipalities have already taken action to ban or limit PFAS. The state of Maryland recently proposed a bill inspired by the death of a firefighter from cancer that would limit exposure to PFAS in fire foam and gear
Needless to say, this issue has caught the attention of lawyers. For the past several years, firefighters have filed lawsuits primarily against the makers of products that contain PFAS, claiming that PFAS was responsible for their health problems. However, a recent article in the National Law Review stated that PFAS litigation is now moving beyond personal injury cases to lawsuits against manufacturing companies that use PFAS as a component of their products.
What Does the Science Say?
PFOA, one of the most studied PFAS compounds, is unique among environmental chemicals in that there is extensive data on its effects in humans. Numerous long-term studies have examined its impact on workers and the general population. The data from animal studies is much sparser than from humans.
“In recent decades, PFAS exposure has been linked to a growing list of problems, including immune system suppression, lower birth weight, and increased risk for some cancers.” – Consumer Reports
Let’s look at the science behind these claims:
Immune system suppression: Epidemiological (human) studies examined whether people with higher levels of PFOA in their blood had
- Decreased levels of antibodies after given vaccines – in 11 studies, 6 were negative, and 5 had mixed findings, such as differences in age groups or the vaccine type.
- Increased incidence of asthma – in 11 studies, 5 positive, 5 negative, I mixed
- Increased number of colds, flu, or other infections – in 6 studies, 1 positive, 3 negative, 2 mixed
- Increased incidence of allergic diseases – in 4 studies, mixed findings
Lower birth weight: Human studies that examined the association between levels of PFOA in mother’s blood and the risk of low-birth-weight babies. In 31 studies, 23 showed no association, and 8 demonstrated that higher PFOA levels were associated with lower birth weight
Cancer: Human studies that examined exposure to PFOA and the risk of various types of cancer. There are 14 studies in total, 7 involving work exposure to PFOA, 3 exposure from nearby facilities, and 4 exposure by the general public.
The seven occupational studies studied workers exposed to PFOA on the job and followed their health histories over the years. These comprise large numbers of workers (up to 9,000 in one study) and have the best estimates of the subject’s actual exposure to PFOA because the companies monitored the workers. The only positive results found in these studies were for prostate cancer, with positive associations only seen at the highest levels of PFOA exposure for long periods of time. The other positive results  were found in general population studies, which were much smaller and had less accurate exposure measurements.
Animal studies provide additional evidence when there are insufficient human studies. Even though there are plenty of human studies for PFOA, animal studies have shown
- PFOA reduces antibody levels in mice but not in rats. There is no consistent evidence of other immunological effects.
- Mixed results on decreases in body weight from maternal exposure to PFOA.
- No increase in cancer in rats exposed to PFOA.
I recognize there remain questions on PFAS that scientists are studying, but the evidence currently available is mixed.
Why Does it Matter?
Science must act as a guardian, alerting the public to situations of real risk. As any scientist knows, if you’re looking for “no risk,” then ban all chemicals because there is no such thing as zero risk. However, if you take a broader approach and consider the risk from exposure to the low levels of chemicals compared to their benefits, that leads to actual science-informed evaluations.
Unrealistic tradeoffs of risk and benefit have far-reaching consequences. Several states have laws prohibiting restaurants from using PFAS in food packaging. Restaurants trying to reduce PFAS use find few options. The available options are much more expensive and less functional. More serious consequences involve the removal of PFAS from fire-fighting foams and gear. Firefighters are exposed to a plethora of toxic chemicals in smoke, including cyanide, carbon monoxide, benzene, and acid gases. The risk from the PFAS in firefighters’ gear and foam is minuscule in comparison. The cost of this action may result in increased deaths from inadequate protective gear and equipment.
It is very rare to have a chemical with so much human data that shows so little adverse effect. Multiple studies did not find an association between PFOA and immune effects, developmental effects, or cancer. Yes, there are some positive studies, but a fair and accurate assessment involves examining the totality of the data and reaching a conclusion based on all studies.
The reason why PFAS is targeted as “dangerous” is two-fold. The media thrives on scary headlines. But the government-science complex, government agencies, scientists, and academicians, have created an environment where EPA is giving out millions of dollars to fund PFAS research - there is absolutely no benefit to a scientist in pointing out that the human studies indicate that these chemicals are quite safe.
In terms of the EPA’s proposal to classify all PFAS as “hazardous substances,” it is good that EPA has started with an ANPRM, the earliest step in the rulemaking process, giving the public extra time for comment and the court challenges, which are sure to follow. However, as a scientist, I believe it is not too late to present a more balanced review of the data, which is not nearly as scary as the headlines would lead us to believe.
- All cancer deaths – 5 studies, all negative
- Prostate cancer – 9 studies, 3 positive, 6 negative
- Kidney cancer - 6 studies – 2 positive, 4 negative
- Pancreatic cancer – 6 studies, all negative
- Bladder cancer – 6 studies, all negative
- Lung cancer – 3 studies, all negative
- Breast cancer – 6 studies, 2 positive, 4 negative
- Liver cancer – 4 studies, all negative
- Testicular cancer – 2 studies, both positive
Sources: ATSDR Toxicological Profile for Perfluoroalkyls. 2021. U.S. Dept. of Health and Human Services, Public Health Service.