Widespread PFAS chemical pollution will likely make COVID-19 worse

These common household and industrial chemicals impair immune system function

Anna Robuck

Marine Science

University of Rhode Island

The COVID-19 crisis has been practically defined by uncertainty – uncertainty about its transmission, why it impacts some people more than others, and how to mitigate risk in our daily lives.  

On June 11, the US Centers for Disease Control (CDC) acknowledged one more uncertainty: we have no idea how a potent family of chemicals, called PFAS (per- and polyfluoroalkyl substances), is impacting our risk for COVID-19. What we do know about PFAS makes this acknowledgement very worrisome. Because of their unique chemical properties that allow them to repel both oil and water, PFAS are everywhere, appearing in Teflon frying pans, stain-resistant carpeting, outdoor gear, and fire-fighting foam, to name just a few.

PFAS are potent immunotoxicants, meaning they impair immune responses in both humans and animals. Research tells us PFAS reduce vaccine efficacy and antibody response in humans, at concentrations readily found in our blood. This was first documented in a study on efficacy of tetanus and diphtheria vaccines in relation to PFAS levels in children from the Faroe Islands. Infants exposed to high PFAS levels in utero had reduced antibody levels at five years old. With each doubling of PFAS in the children’s blood, the overall antibody response was cut by almost 50%. Some children were found to have antibody levels at age five that clinically qualified them for further vaccination, meaning they weren’t adequately protected from diphtheria or tetanus, even though they had already been vaccinated for these diseases as a baby. 

Further research has confirmed the association between reduced antibody responses and PFAS for multiple diseases, in mice as well as in multiple human populations

The lead author of the Faroe Islands study, Dr. Philippe Grandjean from the Harvard T.H. Chan School of Public Health, sees the link between PFAS and COVID-19 based on his previous work. “Given that PFAS are toxic to the immune system, exposure to these persistent chemicals may well worsen the consequences of a COVID-19 infection. Just like recent studies have shown that areas with more severe air pollution have more severe COVID-19 cases and greater mortality, we should also examine if the same applies to communities with PFAS-contaminated drinking water.”

Epidemiological studies reveal that PFAS exposure is associated with other immune-related maladies. These studies suggest people with higher PFAS levels have a harder time fighting off illness, get sicker than folks with lower PFAS levels, and are more likely to suffer from an autoimmune disease. 

However, we aren’t exactly certain how PFAS can cause all these immune outcomes. The immune system is complex, and many facets of its form and function are areas of active research. Our incomplete comprehension of the immune system makes pinning down how chemical exposure influences immune outcomes a challenge. Right now the best solution to mitigate the impacts of PFAS on our immune systems is to remove them from the environment. 

But, as we stare down a continually deteriorating global pandemic, our lives are practically saturated with these immune system saboteurs. Decades of reckless chemical deregulation mean that most people in the US have these compounds in their blood. PFAS are used in everyday consumer products, industrial processes, and military applications, and they make their way out of these intended uses into drinking water, agricultural products, packaged foods, air, soil, surface water, and wildlife. And they remain in the environment or living organisms indefinitely once there. PFAS have never been formally regulated at a federal level, even today. The US Environmental Protection Agency offers unenforceable drinking water guidelines, forcing states to act independently to implement their own regulations. But at a federal level we keep allowing the creation of new PFAS, even as we learn more about the toxic effects of older formulations. 

two vials of blood against a pale green background

Most people living in the United States have PFAS in their blood

Karolina Grabowska on Pexels

Right now, this grim set of circumstances has no happy ending. We know little about COVID-19 on its own, though this is rapidly evolving. And as the CDC acknowledges, we know very little about the interaction of PFAS exposure and COVID-19. But we do know that neither COVID-19 nor PFAS are going to “fade away”, and every ounce of new information about risk or impacts is vital to keep our communities healthy. More research about the relationship between PFAS and COVID-19 is desperately needed. 

But here there is some hope. We already possess tools to figure out the relationship between COVID-19 and PFAS. “PFAS exposures can be determined from the analysis of a blood sample, and we should therefore compare blood-PFAS concentrations in hospitalized patients with those who were infected but escaped any serious disease development,” says Grandjean. Now is the time to leverage these tools, particularly in support of those communities that continue to wrestle with high levels of PFAS exposure with no resolution in sight.

These resources provide more information if you’re concerned about PFAS contamination in your community:

Comment Peer Commentary

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Sree Rama Chaitanya

Molecular Biology

This is a great article, but a scary one too. After reading your article, what scares me the most is, we do not exactly know what PFAS does to our immune system. But as a molecular biologist, I have a hunch. I have quickly looked it up, and It turns out that PFAS might not be a genotoxic to human cells, but it could act as an epigenetic or gene expression modifier. And changes in gene expression or epigenetic memory could trigger a chain of unwanted events leading to immunopathologies (or autoimmune diseases). There is some level of evidence to use epigenetic or gene expression as targets for antiviral therapy. I guess more rigorous work in the future will answer these questions, having said that, right now - stay safe!
(non-scientific note: your article reminds me of Dark Waters

Simon Spichak


Great article. This research is quite troubling.

One of the unfortunate aspects of the manufacturing process is that when we replace certain chemical pollutants, often we aren’t sure whether their replacements are inert either. BPA used to be found in a lot of water bottles and plastics, since being replaced with substitutes. Recent work identified a lot of these substitutes as germline toxins, meaning that genetic changes induced by these chemicals could be passed onto a subsequent generation. It also reminds me of the troubles with leaded petrol, where researchers found that small amount of lead affected the brain and multiple organs! It’s clear more than ever, that manufacturers and companies must do their due diligence to ensure that their products are safe and non-toxic.