Researchers: PFAS exposure linked to vaccine efficacy, children's immune systems

By Shaun Robinson

Boston University Statehouse Program

Published Mar 12, 2021 

BOSTON — A week after a study found higher levels of PFAS in Cape Cod drinking water than was previously known, scientists from Harvard University's T.H. Chan School of Public Health said exposure to the “forever chemicals” can have a negative effect on immune system development in children and is associated with some risk factors for COVID-19.

“We are late in realizing what these compounds do to the immune system, and in the meantime, these PFAS compounds have been spread globally,” Dr. Philippe Grandjean, an adjunct professor of environmental health, said during a public webinar Thursday. “I’ve never met a blood sample that did not contain PFAS. We are all exposed.”

The webinar, hosted by the town of Barnstable and the University of Rhode Island’s Sources, Transport, Exposure and Effects of PFAS program, also covered how per- and polyfluoroalkyl substances have been shown to reduce vaccine efficacy, and offered solutions for mitigating the chemicals’ effects.

Last week’s study, also from Harvard, found PFAS levels above the state maximum for drinking water in the Childs River and Quashnet River watersheds in Mashpee, as well as the Mill Creek watershed in Hyannis. Researchers used a new testing method that detected more PFAS than tests that are typically used by the state and federal government.

PFAS can be found in a wide array of everyday products, such as carpets and upholstery, waterproof clothing, waxes on hardwood floors and skis, nonstick cookware, takeout packaging, dental floss, cosmetics and paints, she said. It can also be found in drinking water, seafood and meat.

Dr. Carmen Messerlian, an assistant professor of environmental reproductive, perinatal and pediatric epidemiology, said in the webinar the chemical properties that make PFAS useful are also what make them dangerous to the human body and the environment.

For mothers, transplacental and breastfeeding passage of accumulated PFAS “is really inevitable,” Messerlian said. Young children also have been shown to have a higher exposure to PFAS because they spend time touching their mouths and are closer to dust sources on the floor, she said.

“It can affect how the child develops and grows and how their immune system — and other organs and other functions — develop over time,” she said. “We know that there could be long, generational effects.”

Overall, Messerlian said, there is “robust evidence” of a negative association between children’s antibody levels and elevated PFAS exposure.

One study, she noted, found that children with exposure to several types of PFAS compounds had a 30% greater risk of developing the common cold. Young children were more susceptible than adolescents, she said, and in some cases boys more susceptible than girls.

Grandjean said PFAS exposure also has been shown to reduce the efficacy of some vaccines in children.

He said one study found that two years after receiving the diphtheria booster shot, children lost about half of their diphtheria antibodies for every doubling of the concentration of PFAS in their blood.

The risk factors for COVID-19 are linked to some of the groups most affected by PFAS exposure, he said. Multiple studies have shown that elderly men and post-menopausal women are more likely to get the virus, and that these groups also have high concentrations of PFAS. Diabetes and obesity, both risk factors for COVID-19, are also associated with high PFAS exposure, he said.

Grandjean said it is too early to tell if PFAS exposure could reduce the efficacy of  coronavirus vaccines currently being used around the world, though it’s certainly possible.

“We need to do studies on immune responses to those different vaccinations that are currently being used to see if the antibody response is appropriate,” he said. “My suspicion is that that may not be true if people have been exposed in the past or currently to elevated amounts of PFAS.”

Reducing PFAS exposure can be difficult, Messerlian said, though one option is to eat fewer processed foods, which may be sold in wrappers or containers made with PFAS. Grandjean said some European countries have banned PFAS in food containers, a move the United States could make as well.

The U.S. also permits higher levels of PFAS in its drinking water, he said. The European Union’s standard for the tolerable weekly intake of PFAS in drinking water is 2.2 parts per trillion, he said. In Massachusetts, the standard is 20 parts per trillion, while the federal standard is 70 parts per trillion.

Amanda Hernandez, a research assistant at the Newton-based Silent Spring Institute, said in the webinar that homeowners on the Cape could take additional precautions by filtering their water using reverse osmosis or activated carbon, both of which have been shown to be effective at removing PFAS.

For more information on water treatment, specifically for private well owners, Hernandez said homeowners can visit web.uri.edu/steep. The site also has a recording of a previous webinar on PFAS and water pollution.