You may have heard of PFAS, or per- and polyfluoroalkyl substances, a group of chemicals that are used in many household and industrial products such as nonstick cookware, waterproof clothing, stain-resistant carpets, and food packaging. These chemicals are also known as “forever chemicals” because they are very persistent in the environment and in our bodies, and they can take decades to break down.

But did you know that exposure to these chemicals may also increase your risk of certain types of cancer? A study published in the Journal of Exposure Science and Environmental Epidemiology² found that women who had higher levels of some PFAS in their blood were more likely to have a history of cancer, especially melanoma, ovarian, and uterine cancer.

The study used data from the National Health and Nutrition Examination Survey (NHANES), a large survey conducted by the Centers for Disease Control and Prevention (CDC) that collects health and environmental information from a representative sample of the U.S. population. The researchers analyzed the blood samples of 48,000 people who participated in NHANES from 2005 to 2018, and compared the levels of 18 different PFAS and phenols (another group of chemicals that includes bisphenol A, or BPA) to their self-reported cancer history.

The results showed that women with higher exposure to PFDE, a long-chained PFAS compound, had double the odds of a previous melanoma diagnosis, and women with higher exposure to two other long-chained PFAS compounds, PFNA and PFUA, had nearly double the odds of a prior melanoma diagnosis. The researchers also found a link between PFNA and a prior diagnosis of uterine cancer, and between phenols such as BPA and 2,5-dichlorophenol (a chemical used in dyes and also found as a by-product in wastewater treatment) and prior ovarian cancer diagnoses.

The researchers noted that these findings are consistent with previous studies that have suggested that PFAS and phenols may disrupt hormone function in women, which is one possible mechanism that increases the risk of hormone-related cancers. However, they also cautioned that the study does not prove causation, and that more research is needed to confirm the associations and to explore the biological mechanisms behind them.

The study also highlighted the need to consider PFAS and phenols as whole classes of environmental risk factors for cancer risk in women, rather than focusing on individual chemicals. This is because these chemicals are often found together in the environment and in our bodies, and they may have additive or synergistic effects on our health.

The study also pointed out the challenges of assessing the exposure and health effects of these chemicals, given that they are constantly changing and evolving. For example, some of the PFAS compounds that were measured in the study have been phased out or replaced by newer ones, which may have different properties and health impacts. Therefore, the researchers called for more comprehensive and updated biomonitoring data and exposure assessment methods to better understand the current and future risks of these chemicals.

The study was conducted by researchers from the University of California, San Francisco (UCSF), the University of Southern California (USC), and the University of Michigan, who are part of the NIEHS-funded P30 centers that focus on environmental health sciences. The lead author of the study, Amber Cathey, is an assistant research scientist in the Department of Environmental Health Sciences at the University of Michigan School of Public Health. The senior author of the study, Max Aung, conducted the research while at the UCSF Program on Reproductive Health and the Environment and is now an assistant professor of environmental health at USC Keck School of Medicine. Aung is also an alumni of the University of Michigan School of Public Health.

(1) Exposure to PFAS chemicals doubles the odds of a prior cancer diagnosis ….

(2) PFAS Exposure and Risk of Cancer – NCI.

(3) Thyroid cancer: Study links ‘forever chemicals’ to higher risk.

(4) ‘Forever chemical’ exposure linked to higher cancer odds in women.