DuPont Co. workers at two Delaware locations have the chemical PFOA in their blood at levels far higher than the general public, according to documents submitted to the Environmental Protection Agency.

The results, from workers at the company’s Experimental Station near Wilmington and a DuPont Performance Elastomers plant in Newark, suggest blood levels of perfluorooctanoic acid that could cause health problems, according to a scientist with an environmental group that has sought to raise the alarm on PFOA and related chemicals.

A DuPont spokesman said the samples were “on the lower end” of workers exposed to PFOA, and industry studies have shown no health effects from exposure to the chemical.

PFOA, also known as C8, has been the subject of scientific and regulatory scrutiny in the last decade. DuPont, which makes PFOA at a facility in North Carolina, uses the chemical as a manufacturing aid in Teflon and other products, and it appears in trace amounts in products like fire-fighting foams and grease-resistant food packaging.

The chemical is long-lived in the environment and has been found in the blood of people across the world at low levels. DuPont and other companies have committed to phasing out PFOA no later than 2015, under a voluntary EPA program.

In November, DuPont tested nine workers at a plant in Tralee Industrial Park in Newark that makes Kalrez rubber parts, used for sealing applications. The testing was part of a voluntary program to evaluate DuPont industrial hygiene controls, and it was the first time workers at the facility had been tested, said DuPont spokesman Dan Turner.

The nine workers had an average PFOA level of 458 parts per billion — about 100 times higher than the level seen in an average American. The results ranged from a low of 137 parts per billion to a high of 1,240.

At the Experimental Station, DuPont’s central research and development campus, the company tested blood levels of three different groups of workers.

One group of 12 workers had an average PFOA level of 421 parts per billion, with levels ranging from 10 parts per billion to 1,480. Another group of six workers had an average level of 324 parts per billion, with results ranging from 8 parts per billion to 1,270. A third group of three workers had an average PFOA level of 20 parts per billion.

DuPont last year submitted testing data from workers at the Chambers Works plant in Deepwater, N.J., where workers make products including fluorotelomers used in food packaging and fire-fighting foams. Those data showed average PFOA blood levels ranging from 15 to 2,163 parts per billion in different groups of workers, and individual levels as high as 4,400 parts per billion.

Studies submitted to EPA

DuPont submitted the studies under a federal law that requires chemical makers to disclose new information about potential health or environmental risks of their chemicals. Turner said the company periodically submits such studies to the EPA to “err on the side of being overly conservative.”

Turner said the typical pathway of exposure for workers at both facilities is inhalation. At the Kalrez facility, workers process a polymer that contains PFOA as a residual component, and researchers at the Experimental Station work with such products in a lab setting.

Turner said DuPont’s goal is to minimize workers’ exposure to PFOA. But regardless, he said, studies from DuPont and other companies on their workers have shown no health effects.

“It is amazing to me that they are still saying that,” said Olga Naidenko, a senior scientist with Environmental Working Group, a longtime critic of DuPont’s handling of information about PFOA.

Naidenko pointed to recent studies linking high levels of PFOA to fertility problems. “That’s clearly a health effect,” she said. “It’s impossible to call it otherwise.”

As part of a settlement in a lawsuit against DuPont, a court-appointed panel of three scientists is studying the chemical’s effect on about 70,000 West Virginia and Ohio residents who live near DuPont’s Washington Works plant, where Teflon is made.

The panel recently reported a possible connection between PFOA and birth defects and high blood pressure in pregnant women, although the scientists downplayed the findings as “weak relationships.”