Blood in children and adults across the country contains a byproduct of chemicals used to keep dozens of household products and clothing clean and dry.
Results of the blood tests are buried in an archive of industry studies at the U.S. Environmental Protection Agency, which is increasingly concerned about a family of chemicals used to manufacture some of the nation’s most popular and widely used products.
The products are marketed as marvels of modern chemistry that repel stains on carpets and furniture, make water bead on raincoats and blue jeans and keep food from sticking to pots and packaging.
But after more than a half century of use without government regulation, manufacturers are trying to figure out how chemicals used to make them have built up in the blood of people as young as 2 and as old as 96.
Federal regulators want answers after concluding last month that one of the chemicals, used by DuPont to make Teflon, might cause developmental and reproductive problems in girls and women of childbearing age.
EPA scientists also are concerned about studies that link the DuPont chemical to a variety of other health problems, including cancer and liver damage in animals.
“The fact that DuPont can’t tell us where it’s coming from means we should be suspect of every potential source, including Teflon,” said Kristina Thayer, senior scientist at the Environmental Working Group, a nonprofit research organization that is urging the government to ban the chemicals.
DuPont says the chemicals are safe and are not dangerous to humans.
At issue is a family of perfluorochemicals that break down in the body or the environment to a chemical called ammonium perfluorooctanoate, also known as C8 or PFOA.
C8 doesn’t break down and accumulates in human blood, according to industry studies.
DuPont has used C8 since the early 1950s to manufacture Teflon. Chemical cousins of C8 are used in a variety of other coatings, known as fluoropolymers and fluorotelomers, that are designed to resist water, grease and stains.
The EPA says more study is needed, but the agency is moving ahead with a process that could lead to the first government regulations of C8 and its chemical cousins.
In a November briefing for the EPA, DuPont scientists told the agency that people might be exposed to the chemicals by ingesting them or absorbing them through the skin. Potential sources include clothing, carpets, cleaning products, food-wrap paper, medical fabric and paints, according to a company presentation.
Details presented by DuPont during the briefing were removed from the EPA’s public files after the company said the documents would reveal confidential business information. More studies are being conducted, but in a summary, the company said one of its concerns was that the products might break down as they age and suffer wear and tear.
DuPont says nearly all of the C8 used to make Teflon is removed during the manufacturing process. About 3 percent remains in unnamed products made with Teflon by other companies, according to a June 2000 letter to the EPA from Gerald Kennedy, DuPont’s chief toxicologist.
Company officials stress that cookware sold under the Teflon brand does not contain C8.
Three Canadian scientists came to a different conclusion in a study published in July 2001 in the scientific journal Nature. The study identified C8 as one of the chemicals released when fluoropolymers, such as Teflon, decompose as they are repeatedly heated.
The study is among several documents that the Environmental Working Group has posted on a Web site (www.ewg.org/reports/pfcworld) that advises people to avoid products containing perfluorochemicals.
DuPont says the group’s concerns are unfounded. Though C8 builds up in blood, the company says its research shows the chemical is not dangerous to humans. DuPont has created its own Web site (www.c8inform.com) that says the chemical is safe.
“PFOA (C8) has been wrongfully represented as a health risk when, in fact, it has been used safely for more than 50 years with no known adverse effects to human health,” said Richard J. Angiullo, vice president and general manager of DuPont’s fluoroproducts division.
Company documents show that DuPont officials have been concerned for years about animal tests that link C8 to health problems. In a 1997 summary of test results, DuPont said company scientists still didn’t understand how C8 caused cancer in animals, “and therefore relevance to humans cannot be completely ruled out.”
C8 and related chemicals were widely used for decades without drawing attention from federal regulators. That changed in the late 1990s after 3M, once the leading manufacturer of the chemicals, informed the EPA that its own tests had detected them in blood samples collected from around the country, and in foods such as apples, bread, green beans and ground beef.
Regulators initially were concerned about a compound that 3M used in its line of Scotchgard stain repellants. The EPA shifted its focus to C8 after 3M announced in May 2000 that it would stop making all perfluorochemicals, citing their persistence in the environment.
DuPont once relied upon 3M for nearly all of the C8 used to manufacture Teflon and related coatings at its Washington Works plant west of Parkersburg, W.Va. DuPont now makes the chemical in Fayetteville, N.C.
The Dispatch reported in February that DuPont has known since the early 1980s that C8 has contaminated public drinking water in communities near the Washington Works plant.
Ohioans didn’t know until last year that they were being exposed to the chemical through water and air.
EPA scientists are concerned about three studies conducted by 3M last year that found both the Scotchgard compound and the Teflon compound in human blood across the nation.
3M’s studies relied upon blood drawn from children ages 2 to 12 in 23 states, including Ohio; and the District of Columbia; adult blood donors in Boston, Charlotte, Hagerstown, Md., Los Angeles, Minneapolis/St. Paul and Portland, Ore.; and senior citizens in Seattle.
Average levels of C8 detected in all three studies were between 4 parts per billion and 5 parts per billion. The highest levels of C8 (56.1 parts per billion) were found in children, leading 3M researchers to speculate that children are exposed more frequently because they play on carpets treated with stain repellants.
“We’re still not sure how it’s getting into people’s blood,” said Rick Renner, a 3M spokesman.
None of the industry studies filed with the EPA identifies specific products made with the chemicals. However, a manual for researchers hired by 3M instructs them to prevent contamination of field samples by avoiding use of products — including some packaging — that contain perfluorochemicals.
Examples in the manual include new clothing, water-resistant clothing, microwave popcorn, fast food, chicken sandwiches, french fries, pizza, bakery items, beverages, candy, cookies and candy bars.