CHARLESTON, W.Va. -- Exposure to the toxic chemical C8 appears to be linked to changes in the human immune system, according to the latest findings of a scientific panel studying the chemical.

The three-person C8 Science Panel found "several significant associations" between the level of C8 in people's blood and the levels of disease-fighting antibodies.

Science panel members cautioned that they did not yet know if the changes in antibodies were caused by increased C8 or not. C8 levels and antibody levels were measured at the same time, and the panel is doing follow-up studies to try to get more answers.

"While this cannot be directly interpreted as indicating an increase in disease risk in this population, it warrants further investigation," the Science Panel said in its report, filed Thursday in Wood Circuit Court.

The panel's findings mirror those made public nearly a year ago by researchers at West Virginia University, who are examining the same data. Both studies are funded by major portions of a $107.6 million lawsuit settlement paid by DuPont Co. in a suit alleging the company poisoned Mid-Ohio Valley residents' water with C8.

In one study, the C8 Health Project, residents gave blood and detailed medical histories to try to give researchers a huge database from which to consider C8's impacts. WVU researchers are analyzing that data and have been making some preliminary findings public.

In the other study, three experts are trying to determine if C8 is linked to adverse health effects. Their conclusion will be used to decide if DuPont must fund a medical monitoring program for residents who drank contaminated water.

Previously, the Science Panel reported that people with higher levels of C8 in their blood tended to have higher cholesterol levels. The panel also reported that Parkersburg-area residents had an average of nearly six times more C8 in their blood than the average U.S. population. The panel said it has so far found no link between C8 exposure and diabetes.

In January, the Science Panel also reported that residents with higher C8 levels in their blood tended to have more uric acid, a bodily waste that has been linked to hypertension and other cardiovascular diseases.

In West Virginia, DuPont has used C8 since the 1950s at its Washington Works plant south of Parkersburg. C8 is a processing agent used to make Teflon and other nonstick products, oil-resistant paper packaging and stain-resistant textiles.

Around the world, researchers are finding that people have C8 in their blood at low levels. People can be exposed by drinking contaminated water, eating tainted food, or through food packaging and stain-proofing agents on furniture or carpet.

Evidence is mounting about the chemical's dangerous effects, but regulators have yet to set a binding limit for emissions or human exposure.

Two recent studies have linked C8 exposure to reduced fertility in women and declining sperm counts in men.

Reach Ken Ward Jr. at kw...@wvgazette.com or 304-348-1702.