CHARLESTON, W.Va. -- Mid-Ohio Valley children with higher exposures to C8 showed a 50 percent increased risk of thyroid disease, according to the latest report from a three-scientist panel examining the toxic chemical's potential health effects.
The C8 Science Panel also reporting finding increases in thyroid hormones in children exposed to two related chemicals, the panel said in a three-page report filed Thursday morning in Wood Circuit Court.
The latest findings come on the heels of a West Virginia University scientific paper that raised questions about C8's possible impacts on thyroid function and another report that found a 25 percent increase in thyroid problems among members of the general U.S. population with higher C8 exposures.
"Taken together, these new findings suggest that normal thyroid function may be affected by exposure to one or more of the family of perfluoroalkyl acids," the Science Panel said in its new status report.
Science Panel members are working to implement a key provision of a $107.6 million class-action settlement between DuPont and about 70,000 residents whose drinking water was polluted by C8 from the company's Washington Works plant south of Parkersburg.
Panel members Kyle Steenland, David Savitz and Tony Fletcher were appointed to study C8 and determine if there is a "probable link" between exposure and illness. If they conclude there is, DuPont could be on the hook for up to $235 million for future medical monitoring for area residents.
The panel has published peer-reviewed papers and separate reports to the court that found C8 exposure associated with a variety of adverse health effects, ranging from high cholesterol and hypertension to birth defects and learning disorders in children. So far, though, panelists have not filed a report in which they either find or rule out a "probable link" between such problems and C8 exposure.
C8 is another name for perfluorooctanoate acid, or PFOA. In West Virginia, DuPont 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 agree on 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.
In their latest work, the Science Panel compared two measures of thyroid hormones -- thyroid-stimulating hormone, or TSH, and total thyroxine, or TT4 -- to levels of C8 in the blood of 10,725 children ages 1 to 18 and to estimates of their mothers' C8 levels at the time of pregnancy.
"Disturbances to the thyroid system, particularly in children, may have a number of negative effects, as thyroid hormones play important roles in regulating metabolism, growth and development, especially in normal brain maturation and development," the panel said in its three-page report.
The report cautioned that the increased risk of thyroid disease was based on a small number of cases with "borderline statistical significance" and that the results "are not sufficient to prove that PFOA is leading to increased thyroid disease." It also said that C8 concentrations and thyroid hormone levels were measured at the same time, making it impossible to know which came first.
The Science Panel has not yet published these results in a peer-reviewed journal, and its reports to the court do not include complete data, making it difficult for other scientists to comment on the results or the panel's commentary about them.Reach Ken Ward Jr. at kw...@wvgazette.com or 304-348-1702.