Exploring how ‘forever chemicals’ may harm immune function

Mounting evidence suggests that widely used chemicals called per- and polyfluoroalkyl substances (PFASs) interfere with immune system function. Experts are concerned that exposure to these chemicals could diminish the immune system’s ability to fight a host of infectious diseases, including COVID-19, according to a recent PNAS article.

People are exposed to PFASs, which have water- and grease-resistant properties, through contaminated water, food, air, and a wide range of consumer products such as nonstick cookware, waterproof clothing, stain-resistant upholstery and carpets, food packaging, and firefighting foams. They’ve been linked with a number of health problems, including thyroid disease, liver damage, and kidney and testicular cancers. PFASs are known as “forever chemicals” because they have extremely strong chemical bonds that make them highly resistant to breaking down in the environment. In 2015, national sampling detected the chemicals in the blood of nearly all Americans.

The PNAS article, published April 13, 2021, highlighted several studies conducted by Philippe Grandjean, adjunct professor of environmental health at Harvard T.H. Chan School of Public Health, that have shown links between PFAS exposure and decreased immune function.

One study, from January 2012, found that a group of children in the Faroe Islands with higher PFAS exposure had significantly less protection from vaccination for tetanus and diphtheria than would have been expected. An April 2021 study found that prenatal exposure to PFAS was associated with an increased risk that children would later be hospitalized for infectious diseases. And in a December 2020 study, Grandjean found that the presence of a PFAS called perfluorobutanoic acid (PFBA) in the blood of Danish adults infected with COVID-19 was linked with nearly double the likelihood of hospitalization, and that some of the hospitalized patients with PFBA exposure were five times more likely to progress to intensive care or death.

Read the PNAS article: How “forever chemicals” might impair the immune system

Learn more

PFAS exposure linked with worse COVID-19 outcomes (Harvard Chan School news)