PFAS forever chemicals linked to lower bone density in teenagers, especially girls

The teenage years are when the human skeleton does most of its heavy lifting. Roughly 90% of peak bone mass is built before age 20, which means anything that interferes with bone development during adolescence can have consequences that stretch across an entire lifetime. A new study has found that PFAS, a family of synthetic chemicals present in a wide range of everyday products, are doing exactly that, with measurably lower bone density recorded in teenagers who had higher PFAS levels in their blood.

The research, published in the journal eBioMedicine, analyzed data from 1,pristine848 adolescents aged 12 to 19 drawn from the U.S. National Health and Nutrition Examination Survey. Participants with higher concentrations of several common PFAS compounds, including PFOA, PFOS, and PFHxS, showed significantly lower bone mineral density scores at the spine and hip compared to those with lower exposure levels. The association held after researchers adjusted for diet, physical activity, calcium intake, and other variables that affect bone health.

Why girls appear to be more affected

The bone density reduction was present in both sexes, but the effect was more pronounced in girls. The researchers believe this comes down to estrogen. PFAS are known endocrine disruptors, meaning they interfere with how hormones function in the body. Estrogen plays a direct role in regulating bone density during puberty, and if PFAS are disrupting estrogen signaling during that window, girls face a compounded disadvantage: their hormone-driven bone-building process gets compromised at exactly the period when it matters most.

This matters beyond adolescence. Lower peak bone density in teenage girls translates to a higher baseline risk of osteoporosis and fractures in adulthood. Women already face greater osteoporosis risk than men as they age due to estrogen decline after menopause. If PFAS exposure during puberty is reducing the bone mass those women start adulthood with, the long-term fracture risk picture becomes considerably worse.

Where PFAS exposure actually comes from

PFAS, which stands for per- and polyfluoroalkyl substances, are a group of more than 12,000 synthetic chemicals that do not break down in the environment or in the human body, which is how they earned the name forever chemicals. They have been used since the 1940s in products that need to resist heat, water, and grease. Fast food wrappers, microwave popcorn bags, non-stick cookware coatings, stain-resistant carpet treatments, waterproof clothing, and firefighting foam are among the most common sources.

Contaminated drinking water is a particularly significant exposure route for children and teenagers. The U.S. Environmental Protection Agency has identified PFAS contamination in water supplies serving millions of Americans, particularly near military bases where firefighting foam has historically been used. A 2023 U.S. Geological Survey study found PFAS in approximately 45% of tap water samples tested across the country. For adolescents drinking tap water daily at home and at school, that exposure accumulates steadily over years.

The regulatory gap researchers are pointing to

The study authors called explicitly for stricter regulatory limits on PFAS in drinking water and food contact materials, arguing that current standards in many countries do not adequately account for the effects on children and adolescents. The EPA set a new maximum contaminant level for PFOA and PFOS in drinking water in April 2024, lowering it to 4 parts per trillion. Environmental health researchers have broadly welcomed that move, though some have argued the limit still needs to go lower given accumulating evidence of harm at very low concentrations.

In the European Union, a restriction proposal covering the broadest possible range of PFAS uses is under evaluation by the European Chemicals Agency. If adopted, it would be the most sweeping PFAS regulation anywhere in the world. The timeline for a final decision has not been confirmed, and industry groups have submitted objections citing economic impact and the lack of available alternatives for some industrial uses.

What parents can realistically do now

Complete PFAS avoidance is not realistic. The chemicals are too widespread. But there are specific steps that reduce exposure meaningfully. Using a water filter certified to remove PFAS, specifically those with NSF/ANSI 58 or 53 certification, addresses the drinking water route. Replacing non-stick pans with stainless steel or cast iron removes a common kitchen source. Avoiding fast food packaging and microwave popcorn bags reduces dietary exposure from food contact materials.

For teenagers specifically, ensuring adequate calcium and vitamin D intake during adolescence is unlikely to fully offset PFAS-related bone density effects based on the current evidence, but it remains the most direct available support for skeletal development. The American Academy of Pediatrics recommends 1,300 mg of calcium daily for adolescents aged 9 to 18. Most teenagers in the U.S. fall well short of that target regardless of PFAS exposure.

The eBioMedicine study is observational, so it shows association rather than confirmed causation. But the biological mechanism is plausible, the dataset is large and nationally representative, and the findings align with prior animal studies showing PFAS disrupts bone metabolism. A longitudinal follow-up tracking the same adolescents into adulthood would be the clearest way to confirm whether the lower bone density observed now translates to higher fracture rates later, and that research is already being planned by several of the study's contributing institutions.