Exposure to two common PFCs associated with increased risk of osteoarthritis

Yale School of Forestry & Environmental StudiesFeb 15 2013

A new study has linked exposure to two common perfluorinated chemicals (PFCs) with osteoarthritis. PFCs are used in more than 200 industrial processes and consumer products including certain stain- and water-resistant fabrics, grease-proof paper food containers, personal care products, and other items. Because of their persistence, PFCs have become ubiquitous contaminants of humans and wildlife. The study, published in Environmental Health Perspectives, is the first to look at the associations between perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), and osteoarthritis, in a study population representative of the United States.

"We found that PFOA and PFOS exposures are associated with higher prevalence of osteoarthritis, particularly in women, a group that is disproportionately impacted by this chronic disease," said Sarah Uhl, who authored the study along with Yale Professor Michelle L. Bell and Tamarra James-Todd, an epidemiologist at the Harvard Medical School and Brigham and Women's Hospital. The research was the focus of Uhl's Master's of Environmental Science Program at the Yale School of Forestry and Environmental Studies.

The authors analyzed data from six years of the National Health and Nutrition Examination Survey (NHANES, 2003-2008), which enabled them to account for factors such as age, income, and race/ethnicity. When the researchers looked at men and women separately, they found clear, strong associations for women, but not men. Women in the highest 25% of exposure to PFOA had about two times the odds of having osteoarthritis compared to those in the lowest 25% of exposure.

Although production and usage of PFOA and PFOS have declined due to safety concerns, human and environmental exposure to these chemicals remains widespread. Future studies are needed to establish temporality and shed light on possible biological mechanisms. Reasons for differences in these associations between men and women, if confirmed, also need further exploration. Better understanding the health effects of these chemicals and identifying any susceptible subpopulations could help to inform public health policies aimed at reducing exposures or associated health impacts.