From Reuters:

High blood levels of a man-made chemical used in non-stick coatings were associated with a raised risk of arthritis in a large new study of adults exposed to tainted drinking water.

Researchers found that people with the highest levels of perfluorooctanoate (PFOA) in their blood were up to 40 percent more likely to develop arthritis than people with lower blood levels more typical of the general U.S. population.

Dr. Kim Innes of the School of Medicine at West Virginia University and colleagues used data on nearly 50,000 adults living in areas of Ohio and West Virginia where a chemical plant had contaminated water supplies with PFOA and perfluorooctane sulfonate (PFOS), both chemicals widely used in non-stick and stain-resistant coatings.

Both chemicals are “persistent organic pollutants,” meaning they remain in the environment and in the human body for years. Both have also been shown to affect human and animal immune systems and metabolism, including functions such as inflammation that are linked with arthritis.

Arthritis is a degenerative joint disease characterized by pain, stiffness and bone damage that affects some 27 million Americans.

To see whether there was a connection between the chemicals and arthritis risk, Innes’ team looked at people being monitored as part of a larger effort known as the C8 Science Panel, established following the settlement of a 2001 class-action lawsuit against DuPont Chemical.

A DuPont plant in Washington, West Virginia, released PFOA, PFOS and other chemicals into the air, which eventually contaminated drinking water.

Overall, nearly 8 percent of the study participants were found to have arthritis. People with the top-25 percent highest blood levels of PFOA were about 20 percent more likely to have arthritis than people in the bottom-25 percent.

Once the researchers adjusted for a variety of factors including, age, weight, socioeconomic status, gender and military service, the people with the highest PFOA blood levels were 40 percent more likely to develop arthritis than those with the lowest levels.