PARKERSBURG - A study in the C8 health project found children with higher levels of C8 in their blood tend to also have higher cholesterol, but the data doesn't prove whether C8 caused it, the report said.
The study, filed Friday in Wood County Circuit Court by the C8 Science Panel, says researchers found higher levels of C8 are significantly associated with high levels of cholesterol. Earlier research tied C8 exposure to high cholesterol levels in adults.
This study was led by collaborators to the Science Panel, including West Virginia University, Stephanie Frisbee, Anoop Shankar, Sarah Knox and Alan Ducatman.
''These investigators have access to the same de-identified data set originating from the C8 Health Project as we do,'' the Science Panel said in the report. ''All three Science Panel members are co-authors on the report being submitted to the journal and concur with its findings.''
Those conducting the study found serum perfluorooctanoic acid (PFOA or C8) has been associated with total cholesterol and other lipids in some studies of exposed workers.
The study population consisted of 12,476 residents under age 18 living at some point in six water districts contaminated by C8 who participated in the large health survey in 2005-2006. The average level of PFOA in the serum was 69 ng/ml while the average level of PFOS, a related chemical, was 23 ng/ml.
''The PFOA levels were much higher than the U.S. population average level of about 5 ng/ml, while the PFOS levels were similar to the average level for the U.S. population,'' the report said. ''In multivariate models adjusting for other factors (age, body mass index, sex, fasting status prior to blood collection), higher PFOA and PFOS were each significantly associated with higher total cholesterol and LDL cholesterol. There were no consistent trends between PFOA and either HDL or triglycerides. Higher PFOS was associated with higher HDL, but showed no trend with triglycerides.''
Only modest associations between PFOA and PFOS and some lipids in children have been seen, the study said.
''Interpretation of these results is made difficult by the cross-sectional design of our study, which prohibits knowing whether an increase in cholesterol (or LDL cholesterol) may have followed or preceded an increase in PFOA or PFOS,'' the report said. ''The mechanism by which these chemicals might be related to cholesterol in humans is not known. These data alone cannot prove whether the PFOA and PFOS differences in these children caused the observed shift in cholesterol, or whether there is another explanation.''
Another explanation could be that there is an unknown exposure or another substance in the blood that correlates both with increased lipids and with increased retention of C8 and PFOS in the blood, according to the report.
The Science Panel is conducting more definitive studies to try to determine which of these possibilities is more likely.
''The fact that both PFOA and PFOS were associated with increases in cholesterol may indicate an association with this chemical class (perfluorinated compounds) in general, rather than specifically either PFOA or PFOS,'' the report said. ''These findings for total cholesterol and LDL cholesterol in children are similar to a previous finding in adults in this same population.''
The research was conducted as part of a settlement of a class-action lawsuit brought by Ohio and West Virginia residents against DuPont Co. The residents allege exposure to ammonium perfluorooctanoate from DuPont's Washington Works plant. Also known as PFOA or C8, the chemical is used to make Teflon.
