Two experts on the possible cancer-causing effects of chemicals disagreed sharply last night in a debate at the Kennedy School Forum on the role the government should play in the regulation of carcinogens.

Samuel S. Epstein, professor of occupational and environmental medicine at the University of Illinois and author of the recently published book, "The Politics of Cancer," said the government is hindered in its attempt to regulate carcinogens because industries have withheld data on worker exposure.

"There is a record of criminality in industry," he said. "They'll use any tactics from Watergatism to appealing to inflation to avoid giving us the data we so desperately need," he added.

Ronald A. Lang, executive director of the Synthetic Organic Chemical Manufacturer's Association said independent scientists, not government legislators, should be making decisions on carcinogens.

Lang agreed that the government should regulate carcinogenic chemicals but said that the large gray area between what the government should regulate and what it shouldn't had to be defined. "How to you separate the wheat from the chaff?" he said.

"We have been encouraging them to get involved in the public policy debate, but they are afraid to," Lang said. "We have been encouraging them to get involved in the public policy debate, but they are afraid to," he said. "We had to go to other countries to get people to speak out because the grants our scientists are getting prevent them from publicly disagreeing with the government."