CHARLESTON, W.Va. -- Thousands of people who drank Parkersburg city water contaminated with C8 cannot sue DuPont Co. in a class action lawsuit over the company's pollution, a federal judge has ruled.

Chief U.S. District Judge Joseph R. Goodwin has refused to certify a class of residents in a suit that sought medical monitoring for C8-related illnesses.

Click here to read Goodwin's ruling

The case is being closely watched around the country, with DuPont facing a similar lawsuit in New Jersey and two dozen state-level class action suits that allege C8 leached from Teflon-coated pans.

In a 32-page opinion issued Tuesday, Goodwin said lawyers for Parkersburg residents "presented compelling evidence exposure to C8 may be harmful to human health, and the evidence justifies the concerns expressed by plaintiffs in this case."

But the judge said he remained unconvinced the lawsuit was proper for handling as a single class action, rather than many multiple individual suits.

"I cannot certify a class based on some potential harm to the general public, rather, there must be specific injuries to each member of the proposed class," Goodwin wrote. "The fact that a public health risk may exist is more than enough to raise concern in the community and call government agencies to action, but it does not show the common individual injuries needed to certify a class action."

C8 is another name for ammonium perfluorooctanoate, or PFOA. DuPont has used the chemical 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.

CHARLESTON, W.Va. -- Thousands of people who drank Parkersburg city water contaminated with C8 cannot sue DuPont Co. in a class action lawsuit over the company's pollution, a federal judge has ruled.

Chief U.S. District Judge Joseph R. Goodwin has refused to certify a class of residents in a suit that sought medical monitoring for C8-related illnesses.

Click here to read Goodwin's ruling

The case is being closely watched around the country, with DuPont facing a similar lawsuit in New Jersey and two dozen state-level class action suits that allege C8 leached from Teflon-coated pans.

In a 32-page opinion issued Tuesday, Goodwin said lawyers for Parkersburg residents "presented compelling evidence exposure to C8 may be harmful to human health, and the evidence justifies the concerns expressed by plaintiffs in this case."

But the judge said he remained unconvinced the lawsuit was proper for handling as a single class action, rather than many multiple individual suits.

"I cannot certify a class based on some potential harm to the general public, rather, there must be specific injuries to each member of the proposed class," Goodwin wrote. "The fact that a public health risk may exist is more than enough to raise concern in the community and call government agencies to action, but it does not show the common individual injuries needed to certify a class action."

C8 is another name for ammonium perfluorooctanoate, or PFOA. DuPont has used the chemical 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 people have C8 and other perfluorochemicals, or PFCs, in their blood at low levels. Evidence is mounting about the chemical's dangerous effects, but regulators have yet to set a federal standard for emissions or human exposure.

In September 2004, DuPont agreed to a $107.6 million settlement with residents of communities around Parkersburg. The money is funding two major studies of C8's health impacts, and DuPont also installed treatment systems to get the chemical out of local water.

Then-Wood Circuit Court Judge George W. Hill had certified those communities' case as a class action. But at the time the settlement deal was made, C8 had not yet been found in the Parkersburg city water supply. Later, C8 was detected there, and a follow-up lawsuit was filed.

Under a 2005 federal, the federal courts must handle proposed class actions involve significant amounts of money or parties from different states. So the follow-up case against DuPont ended up in federal court. Goodwin was asked to allow the case to proceed on behalf of everyone who has been a Parkersburg water customer for at least one year since Nov. 1, 2005.

Lawyers for the residents presented evidence that Parkersburg city water has more C8 in it than the amount that prompted DuPont to settle the 2004 case. They also presented evidence about public health agency recommendations to limit C8 exposure, and that C8 levels in Parkersburg city residents' blood was higher than the general population.

But Goodwin found, "this direct evidence does not demonstrate the plaintiffs can commonly prove each of the proposed class members has been significantly exposed to C8.

Goodwin said comparisons to DuPont's previous settlement "did not constitute a concession by DuPont about the quantity of C8 that must be in drinking water to effect a significant exposure."

Public health agency recommendations likewise, "provide no comparison between the exposure of the proposed class and the general population," Goodwin said.

C8 blood levels of the named plaintiffs -- the individuals representing the class -- mean nothing, Goodwin said, because their lawyers did not "establish a relationship between the class' common characteristic (that is, a common source of drinking water) and the C8 levels in the named plaintiffs' blood."