Women exposed to toxic PFAS “forever chemicals” prior to pregnancy face an elevated risk of being unable to breastfeed early, new research finds. The study tracked lactation durations for over 800 new moms in New Hampshire and found higher PFAS exposure could cause lactation to slow or stop altogether within six months. The findings are “cause for concern” said Megan Romano, an epidemiologist at Dartmouth University and the lead author. “For all women who are exposed, there’s a little bit of a decrease in the amount of time they breastfeed beyond delivery,” Romano said. PFAS are a class of about 16,000 compounds used to make products resist water, stains and heat. They are called “forever chemicals” because they do not naturally break down and have been found to accumulate in humans. The chemicals are linked to cancer, birth defects, liver disease, thyroid disease, plummeting sperm counts and a range of other serious health problems. A 2021 study found all breast milk samples that researchers examined to contain levels in milk ranging from 50 parts per trillion (ppt) to more than 1,850 ppt. There are no standards for PFAS in breast milk, but the Environmental Protection Agency found virtually no exposure to some kinds of PFAS in water is safe, and set a legal limit of 4 ppt. Meanwhile, research from earlier this year found the chemicals reduce milk’s nutritional quality. The new study found higher exposure led to a 28% higher risk of stopping exclusive breastfeeding before six months and some stopped breastfeeding altogether. Only about one-third of US moms breastfeed beyond 12 months, though the World Health Organization and major pediatric groups recommend up to two years and beyond. The study may help explain why many US women stop breastfeeding early, though socioeconomic issues and other factors could play a role, Romano said. PFAS are known endocrine disruptors though researchers have yet to figure out the biological mechanism that causes lactation periods to shorten, Romano said. The study looked at five PFAS chemicals and found the strongest correlation among PFOS and PFOA, which are considered the most dangerous, and ubiquitous PFAS compounds. It is difficult for individuals to protect themselves because PFAS contamination is so widespread. Food and water are main exposure routes, and testing and filtering water, and eating a varied diet, can be beneficial, Romano said. She also suggested using a HEPA air filtration system in the home to reduce PFAS that may be in dust and air.