Study in Denmark links PFBA chemicals with severe COVID

Researchers in Denmark say they think they’ve demonstrated a link between patients who experience more severe cases of COVID-19 and the exposure to perfluorobutanoic acid (PFBA) in those same patients.

If they’re right – the paper is still under peer review – the findings may prove to be the latest to demonstrate a relationship between the coronavirus infection and the impacts of environmental pollution. That’s already been seen in a French study, published in October, that suggests a link between endocrine-disrupting chemicals including the perfluorinated alkylate substances (PFAS) and severe COVID infection.

PFBA is one of those chemicals but when it builds up in the human body, it accumulates in the lungs.

Both the Danish researchers and a United States team have pointed to underlying damage from pollution in the lungs, which makes clear sense when talking about particulate matter. The PM2.5, or airborne particles with a diameter of 2.5 micrometers or less, can enter a person’s lungs and make them less able to cope with the COVID infection. That may mean higher COVID mortality rates and the potential for higher rates of the infection’s spread in environmentally marginalized communities.

But the new preprint paper from Denmark finds perhaps a more subtle but no less troubling correlation between severe COVID and concentrations of PFBA, among those chemicals in the long-scrutinized PFAS family. This class of synthetic polymers, including PFOS and PFOA, is implicated in human health risks, with decades’ worth of chemicals from various PFAS products – plastics, nonstick coatings, raincoats – now nearly ubiquitous in the planet’s water, soils and plants.

The PFBA was one of five PFAS compounds, all known to have immunotoxic properties, that researchers led by Dr. Philippe Grandjean at the University of Southern Denmark evaluated. They looked at 323 plasma samples from known COVID-positive patients, provided by the Danish National Biobank at the Statens Serum Institut and Odense University Hospital. The samples came from people ages 30 to 70 years old.

After adjusting for other factors, the researchers determined that the higher PFBA concentrations were linked with more severe COVID-19 disease outcomes. But none of the other four PFAS compounds showed a similar link, and some were even associated with lower risk of severe COVID outcomes.

“This finding may at first seem surprising, as this PFAS has a short elimination half-life in the blood and is often considered of less importance to health,” the authors note. In fact, the PFBA is a shorter chain polymer that was developed as a safer, more environmentally friendly alternative to other PFAS chemicals.

“Given the persistence of the PFASs in general, the unique retention of PFBA in lung tissue may offer a clue to interpreting the findings in this study,” the Danish scientists said.

What’s more, the findings may point to a better understanding of how well vaccines may perform because of the presence of PFAS chemicals. The authors note previous research in both children and adults that found elevated PFAS exposure is associated with lower antibody responses to vaccinations.