Early life exposure to PFAS associated with common childhood leukemia

Early exposure to PFAS, a group of widely used compounds known as "forever chemicals," was associated with a higher risk of acute lymphoblastic leukemia, the most common childhood cancer, according to University of California, Irvine Joe C. Wen School of Population & Public Health researchers.

The findings were published recently in the Journal of Exposure Science & Environmental Epidemiology, a Nature journal.

PFAS are found in drinking water, food and beverage containers, and everyday items like nonstick cookware and stain-resistant fabrics. They don't break down easily and can build up in the body over time.

The study adds to earlier research by the same team, which tracked PFAS exposure in drinking water among more than 40,000 California children. That work, published in Environmental Epidemiology, linked higher levels of two common PFAS chemicals, PFOA and PFOS, to increased risk of several childhood cancers, including acute myeloid leukemia and Wilms tumor.

In their new study, the researchers analyzed dried blood spots collected from newborns to get a clearer picture of early exposure. The study included 125 children diagnosed with acute lymphoblastic leukemia and 219 children without cancer, all born in Los Angeles County between 2000 and 2015, and identified through the California Linkage Study of Early-onset Cancers.

Among 17 PFAS detected in the newborn blood, PFOA and PFOS showed up at the highest levels. Children with higher levels had increased odds of developing leukemia, though the estimates were not precise. Risk also appeared to rise with combined exposure to the two chemicals.

Researchers also identified 26 additional PFAS compounds, several of which showed similar patterns, including some that have rarely been studied.

Stronger links were seen among non-Hispanic children, though researchers cautioned that those findings are preliminary due to small sample sizes.

This research moves us closer to understanding what babies are exposed to from the very start by directly measuring PFAS present at birth, rather than estimating exposure from drinking water. By capturing exposures during a critical window of development, we are gaining a clearer picture of how environmental contaminants may contribute to childhood cancer risk."

Veronica Vieira, corresponding author, chair and professor of environmental and occupational health at Wen Public Health

The study does not prove cause and effect, but it adds to growing evidence that PFAS exposure early in life may contribute to cancer risk in children.

As PFAS contamination remains widespread, researchers say more studies are needed to understand how this persistent class of chemicals, the majority of which remain largely unmonitored, may affect children's health and how exposure can be reduced at the population level.

The research was supported by a National Institutes of Health grant.

Additional authors include Natalie R. Binczewski of UC Irvine; Sheng Liu, Jeremy Koelmel and Krystal J. Godri Pollitt of Yale University; Libby M. Morimoto and Catherine Metayer of UC Berkeley; Joseph L. Wiemels of the University of Southern California; and Xiaomei Ma of the Yale School of Public Health.