Nevertheless, the overall picture presented by the data strongly suggests that - without violating any environmental law - industries across the country are able to release cancer-causing chemicals in concentrations sufficient to pose an extraordinary risk to public health, Waxman said.
Waxman said he released the data to dramatize the need for legislation that would severely tighten federal regulations on toxic emissions.
"The seriousness of the risk before us cannot be dismissed," Waxman said. The statistics, he added, represent a "stunning demonstration of the urgency of the public-health threat" from unregulated toxic emissions.
The EPA estimates that 2.7 billion pounds of toxic chemicals are emitted annually. While federal agencies recognize more than 100 chemicals released as potentially hazardous, current EPA regulations impose ceilings on emissions of only seven of them.
Among the carcinogenic pollutants unregulated when emitted by industries into the air are butadiene, produced by rubber manufacturers; chloroform, produced by the pulp and paper industry; and ethylene oxide, produced in sterilization processes.
In evaluating harmful chemicals, the EPA generally considers a cancer risk higher than 1-in-1 million as unacceptable. The estimate reflects the risk for the most exposed person living near a source based on a lifetime of inhaling the pollutant.
The figures indicated that 205 facilities posed cancer risks that may exceed 1-in-1,000 for the most exposed individuals. Forty-five of these facilities had maximum individual risks of greater than 1 in 100, and one - a Texaco plant in Port Neches, Texas - had at least a 1-in-10 risk.
Many of the facilities listed as posing a severe cancer risk were in the ''chemical corridor" region of Texas and Louisiana, well-known as a source of toxic pollutants. Other concentrations were in the industrial Northeast and the Great Lakes area.
Reichhold Chemicals Inc., based in White Plains, N.Y., turned up on the list because of butadiene emissions at its plant in Cheswold, Del., the company said.
The EPA data showed that the Cheswold plant posed a risk of at least 1 in 100, but less than 10 in 100. Reichhold said the report was based on five- year-old information and is no longer valid.
"Also, the estimated risks have not been substantiated and are, therefore, questionable," said a Reichhold spokesman. "Reichhold's Cheswold . . . plant has reduced its emissions of butadiene substantially. We also have a continuing program to further reduce emissions at all our plants."
The West Co. of Phoenixville was cited for its plant in Jersey Shore, Lycoming County, Pa., where the company assembles medical devices such as intravenous sets. The government data indicate that the West plant has a risk of at least 1 in 1,000, but less than 1 in 100.
George Bennyhoff, the company's senior vice president for human resources and public affairs, said he believes the EPA report refers to ethylene oxide, a sterilizing agent used at the plant. He said the company complies with environmental laws.
"We have taken the initiative to improve the handling of ethylene oxide, and we have worked very closely with the state Department of Environmental Resources on the development of this system," he said.
He said the company has worked with the state for 18 months on that project.
The release of the provocative data brought an angry outcry from industry representatives.
"To imply that these estimates depict the real risks of living near one of the plants is not just exaggeration but an outright misuse of data to deliberately alarm people," the Chemical Manufacturers Association said in a statement.
An EPA spokesman, Dave Cohen, also said that the report was based on dated information and noted that one of the 205 plants listed as a severe threat no longer existed.
"For people who live around these plants, it is irresponsible for anyone to interpret these data as representing the actual risk of cancer," he said.