Washington ? A wide variety of food in American supermarkets is contaminated with tiny doses of toxic manmade chemical flame retardants, according to a new study of everyday groceries released Wednesday.

Samples of grocery stores’ fish, pork, duck, turkey, cheese, butter, milk, chicken, ice cream and eggs were tainted with polybrominated diphenyl ethers, known as PBDEs, according to a peer-reviewed article in the journal Environmental Science & Technology.

Because this is a relatively new health concern, no one has studied yet if PBDEs are harmful to humans and at what levels, the Environmental Protection Agency’s top toxicologist said. However, in animal tests they’ve harmed the nervous system, altered hormonal function and changed the development of reproductive organs. The federal government has ruled that one PBDE in large doses is a possible human carcinogen.

Wednesday’s finding indicates that the group of chemicals — used in carpeting, electronics and furniture — is getting into people through their food and remains in the body for several years.

Industry officials said the amounts were too small to worry about.

In the study, scientists found the chemicals in 31 of 32 common and name-brand groceries in three Dallas stores, which they said should be typical of most American supermarkets. Only nonfat milk came up clean. Scientists said animal fat was a big factor.

“It’s the first documentation that PBDEs are widespread in food that the American population would eat and that the concentrations in food are high enough for a chemical like this that it is going to persist in our bodies,” study co-author Linda Birnbaum said. She’s the EPA’s director of experimental toxicology and the president of the Society of Toxicology, a professional organization of scientists.

The amounts of PBDEs in U.S. groceries were nine to 20 times higher than those in foods in grocery stores in Spain and Japan, where not as many PBDEs are used, the study reported. This matched earlier studies of elevated PBDE levels in human breast milk, which found American amounts 10 to 100 times higher than elsewhere, said Arnold Schecter, a University of Texas environmental sciences professor who co-wrote the most recent study.

“We’re documenting it at the highest levels in the world in the United States, everywhere we look,” Schecter said.

He said there were no PBDEs in the human body 40 years ago, before use of the chemicals began.

Because health officials don’t know what levels of PBDEs are safe, Birnbaum recommends that people follow “heart-healthy” diets, which cut down on fats that store PBDEs and other toxins.

The amounts of PBDEs found in food ranged from 1 part per trillion for margarine to 3,078 parts per trillion for salmon.

Those levels are “millions of times below acceptable limits,” said Peter O’Toole, the U.S. director of the Bromine Science and Environment Forum, which represents the three chemical companies that produce these types of flame retardants. A person would have to eat 80 tons of cheese a day to ingest enough of one certain type of PBDE to be harmful, he said, basing his analysis on a National Academy of Sciences risk assessment in 2000 for that type of PBDE in the textile industry.