What You Should Know About PFAS

"In the eight decades since they were created, so-called forever chemicals have reached remote corners of the Arctic and been detected in the open ocean and the tissue of animal species as diverse as polar bears and pilot whales.

Also known as PFAS, or per- and polyfluoroalkyl substances, they can stay in the environment for years without breaking down.

Nearly everyone in the U.S. is believed to have some level of PFAS in their blood, according to the Centers for Disease Control and Prevention.

Scientists are still studying the effects of human exposure to PFAS. Here's what to know.

Routes of ingestion

People can ingest PFAS through food or water, or encounter them in consumer products. More than 2,800 locations in the U.S. have found PFAS in the drinking water, according to the Environmental Working Group, a nonprofit that tracks the chemicals.

"If people are in a place that has high contamination, then water is going to be important," said Phil Brown, an environmental sociologist at Northeastern University in Boston who has studied the chemicals. "But for the average person who doesn't have high levels of contamination, food is very often considered to be the most primary route."

PFAS might pass to food from packaging, or produce and dairy could have PFAS from PFAS-tainted sludge used as a fertilizer, Dr. Brown said.

Evidence so far suggests that ingested PFAS is absorbed from the intestine, and can travel to the liver, pass into bile and get stored in the gallbladder, said Jamie DeWitt, an environmental toxicologist at East Carolina University. When bile enters the small intestine during digestion, the PFAS gets reabsorbed into the bloodstream.

Are PFAS harmful?

The U.S. lacks comprehensive national testing of PFAS in blood, which makes it difficult to know who is most exposed, according to Jane Hoppin, an environmental epidemiologist at North Carolina State University.

The CDC's blood-monitoring effort wouldn't capture contamination hot spots where people are more highly exposed to PFAS, she said. That is one reason PFAS health harms are difficult to assess.

Scientists have found links between PFAS and a handful of health problems, including high cholesterol, a decreased immune response to vaccines, and an increased risk of kidney cancer, according to a 2022 report published by the National Academies of Science, Engineering and Medicine.

Many studies have examined PFAS and occurrence of ulcerative colitis, thyroid disease, and breast and testicular cancer, suggesting a link between the chemicals and an increased risk of each disease, said the National Academies report.

Risks to pregnancy?

PFAS exposure is linked to an increased risk of high blood pressure during pregnancy, according to the National Academies report. PFAS blood levels in mothers are also linked with low birth weight.

Fetuses and infants are generally more vulnerable to harmful chemicals than adults because their brain and critical organs are rapidly developing, according to Laurel Schaider, an environmental-health expert at the Silent Spring Institute in Newton, Mass.

PFAS can pass through the placenta of a pregnant woman to the growing fetus, and PFAS can be transmitted to infants through breast milk, the report said." [1]

1. U.S. News: What You Should Know About PFAS
Subbaraman, Nidhi.  Wall Street Journal, Eastern edition; New York, N.Y. [New York, N.Y]. 15 Mar 2023: A.3.