Some everyday paper products are contaminated by tiny amounts of the cancer-causing chemical dioxin, but concentrations of the pollutant are too low to warrant public health concern, government and industry officials said yesterday.

The findings that trace levels of dioxin exist in products ranging from stationery to disposable diapers emerged in an ongoing industry survey of off-the-shelf items. Although dioxin causes cancer and reproductive and immune system problems in rodents, such test animals are exposed to levels of the chemical thousands of times higher than humans could absorb from the paper products, according to federal scientists.

The industry began to sample products after the Environmental Protection Agency, in a national study of dioxin, found low levels in the sludge, effluent and pulp of five paper mills and in fish caught downstream of the paper plants. The pollutant is believed to be a byproduct of the bleaching process that turns paper white.

"I'm not going to change my purchasing patterns as far as products produced with bleached paper," Jack Moore, assistant EPA administrator for pesticides and toxic substances, said at a news conference to release the study.

"There's no basis to be concerned at this time that any of these products are unsafe," he said, adding that the risks posed by such low levels "get down to negligible."

The EPA study, mandated by Congress, found dioxin levels in one-quarter of the fish caught in major U.S. water bodies, with the largest number of contaminated catches in the Great Lakes. None of the fish exceeded the safety standards set by the Food and Drug Administration, but several contained high enough levels of dioxin to warrant advisories to fishermen in Minnesota, Maine and Wisconsin.

Excessive levels of the chemical also were found at the sites of more than 100 manufacturers and formulators of now-banned pesticides that had contained dioxin.

But the most far-reaching dioxin concerns surfaced in the supplementary study by the paper industry that traced the presence of the dangerous chemical from the environment to products with which consumers have regular and intimate contact.

Dioxin is a family of chlorinated compounds of which 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is the most toxic. TCDD, the chemical found in paper, is an unintended byproduct of certain pesticides and the combustion of chemicals found in leaded gasoline and municipal sewage.

TCDD is classified by the EPA as a probable human carcinogen, although its only proven danger to humans is a disfiguring skin disease called chloracne. The herbicide Agent Orange, used in the Vietnam war, contained TCDD, and many U.S. veterans blame it for their high rate of cancer.

The industry study by a consultant of the American Paper Institute (API) found trace amounts of dioxin in two categories of products: personal care items -- such as facial tissue, toilet paper, sanitary pads and paper towels -- and paper used for communications, including stationery, typing paper, envelopes and computer paper. Paper used to wrap food and drugs also was tested, but analysts had difficulty extracting the chemical, API president Red Cavaney said in an interview.

According to Cavaney, preliminary findings of the study showed TCDD levels in the low parts per trillion (ppt) ranging from 2.1 ppt in disposable disapers to 13 ppt in writing paper.

"When you look at those levels," he said, "the industry has the utmost confidence in the safety of our products." The study is to be completed in a month.

A consultant hired by the EPA to assess the risk of TCDD has preliminarily estimated that a lifetime of daily exposure to 10 ppt in paper plates, towels, tampons and diapers increases the chances of cancer by between one in 100,000 and one in a million, according to Donald Barnes, who is science adviser to EPA's Moore.

But in paper coffee filters, the risk increases dramatically, ranging from one in 1,000 to one in 10,000, he said.

A similar chemical, tetrachlorodibenzofuran (TCDF) was discovered in larger concentrations by the industry, but Cavaney said it is believed to be much less toxic than TCDD.

Ellen Silbergeld, a toxicologist for the Environmental Defense Fund, said that despite the low levels of TCDD, the industry findings "can't be dismissed as trivial" because the chemicals accumulate in the body and persist for long periods.

She added that the extent of danger is still unclear because the industry has only tested for one of the dangerous dioxins, and she called on the EPA to ban the bleaching process at paper mills to eliminate the risk.

Moore, who noted he was told of the industry study a few days ago, said that before taking regulatory action the agency will try to gauge the extent of the problem in paper products and better understand the effects of bleaching. Barnes added that it also must be determined if people can absorb the chemical from paper, which tends to be tightly bound in the product.

Cavaney said that while all 86 of the nation's paper-bleaching mills do not use the same process, all of them contain dioxin. "Nobody has totally eliminated dioxin and created pure white paper anywhere in the world," he said.