PFAS Exposure Linked to Worse Bone Health in Young People

Exposure to per- and polyfluoroalkyl substances (PFAS) can lead to lower bone density in adolescents and young adults – particularly for those of Hispanic origin, according to a new longitudinal study published in Environmental Research.

Human health and PFAS

PFAS are sometimes known as “forever chemicals” as they do not break down in the environment. Nonetheless, they are used for a variety of applications including food packaging, cosmetics and cookware.

The chemicals have become increasingly linked with negative health outcomes such as reproductive problems and increased cancer risks. Mounting evidence now suggests PFAS are also associated with lower bone mineral density – a potential cause of bone diseases such as osteoporosis.

Bone mineral density increases during adolescence, peaking between 20–30 years of age, then gradually decreases throughout adulthood. A person’s peak bone mineral density can help predict if they will get osteoporosis later in life.

However, most studies examining the effect of PFAS on bone density have focused on non-Hispanic white participants, despite Hispanic individuals facing elevated risks of bone diseases.

“This is a population completely understudied in this area of research, despite having an increased risk for bone disease and osteoporosis,” said Vaia Lida Chatzi, professor of population and public health sciences at the Keck School of Medicine of USC and the senior author of the study.

Chatzi’s research team sought to redress this discrepancy by carrying out a longitudinal study of young participants – primarily of Hispanic origin – and analyzing the effect PFAS exposure had on their bone density.

PFAS linked to lower bone density

The researchers studied two groups of participants from the Study of Latino Adolescents at Risk of Type 2 Diabetes and the Southern California Children’s Health Study, analyzing data from 304 adolescents (aged 8–13) and 137 young adults (aged 17–22).

“Many existing studies haven’t included participants this young, but we’re now able to see that this association is already happening at a time when bones are supposed to be developing,” said Emily Beglarian, lead author of the study and doctoral student at the Keck School of Medicine.

Adolescents underwent PFAS blood testing and bone density scans, which were followed up approximately a year and a half later. On average, when baseline levels of one type of PFAS – perfluorooctanesulfonic acid (PFOS) – doubled, bone mineral density decreased by 0.003 g/cm² per year at follow-up.

Meanwhile, young adults underwent blood testing and scans then were followed up approximately four years later. When baseline levels of PFOS doubled, participants had an average of 0.032 g/cm² lower baseline bone mineral density, though no significant change was observed over time.

Understanding the effects of PFAS in more detail

Overall, the findings suggest that PFAS exposure was linked to decreased bone mineral density in adolescents over time. For young adults, although PFAS exposure was linked to lower baseline bone density, there was no significant change over time.

Stricter PFAS regulations are needed, say the researchers, as the chemicals contaminate public drinking water, food and soil across the United States, and regulation could protect high-risk communities such as Hispanics.

“PFAS are ubiquitous – we are all exposed to them,” Chatzi said. “We need to eliminate that exposure to allow our youth to reach their full potential in terms of bone development to help them avoid osteoporosis later in life.”

“It’s important to regulate PFAS as a class because we are not just exposed to one chemical, we are exposed to thousands of chemicals,” Chatzi said.

The researchers are now planning outreach efforts to help people learn how to limit their exposure, such as by avoiding non-stick pans and personal care products known to contain PFAS.

Additionally, Chatzi and colleagues aim to confirm the findings across the lifespan and in other communities throughout the US, continuing their focus on Hispanics. Understanding the biological mechanisms underpinning how PFAS affects bone health is also a priority, and the researchers are now looking for biomarkers that could warn of risks to bone health before osteoporosis develops.

Reference: Beglarian E, Costello E, Walker DI, et al. Exposure to perfluoroalkyl substances and longitudinal changes in bone mineral density in adolescents and young adults: A multi-cohort study. Environ. Res. 2023:117611. doi: 10.1016/j.envres.2023.117611

This article is a rework of a press release issued by Keck School of Medicine at USC. Material has been edited for length and content.