C8 study raises questions about thyroid impacts
CHARLESTON, W.Va. -- A new West Virginia University study cautions that exposure to the toxic chemical C8 may affect the function of the thyroid gland and says more research on the matter is needed.
The study, published in the latest edition of the Journal of Toxicological Sciences, found that C8 exposure was associated with elevations of one thyroid hormone and decreased uptake of another. Through these hormones, the thyroid helps control how quickly the body uses energy and makes proteins and controls how sensitive the body is to other hormones.
WVU researcher Sarah Knox and other authors examined thyroid test data from the C8 Health Project -- a review of C8 involving 70,000 Mid-Ohio Valley residents -- and reported "evidence for disruption of thyroid function related" to C8.
The authors noted that the absence of one key piece of data -- measurements of a blood protein that binds with thyroid hormones -- made it difficult to figure out exactly what the findings mean for thyroid function.
Still, they wrote, "the pattern of findings reported here is clinically disturbing."
Earlier this year, another study by researchers at the University of Exeter tested the blood of 4,000 U.S. adults and found the 25 percent with the highest C8 levels had twice the incidence of thyroid problems.
The C8 Science Panel, a three-person committee also looking into the chemical's effects, is still working on its study of possible impacts on the thyroid gland.
C8 is another name for perfluorooctanoic acid, or PFOA. In West Virginia, DuPont Co. has used C8 since the 1950s as a processing agent to make Teflon and other nonstick products, oil-resistant paper packaging and stain-resistant textiles.
DuPont and other companies have reduced their emissions and agreed to a voluntary phase-out of the chemical, but researchers remain concerned about a growing list of possible health effects and about the chemical's presence in consumer products, as well as continued pollution from waste disposal practices.
Reach Ken Ward Jr. at firstname.lastname@example.org or 304-348-1702.