Document BgjoLbjmd0qpMKMNdRmvZ1M4

1800 CHEMICAL REGULATION REPORTER the acceleration of pesticide reregistration and greater pub lic acceu to health and safety data submitted by registrants. Other changes would mandate that pesticide "special reviews" be completed within 11 months of their initiation, allow any person adversely affected by a pesticide cancella tion to request a hearing, and establish oew requirements for recordkeeping. ** Assessment ERA MAY CHANGE ASSUMPTIONS TO REDUCE ^ OVERESTIMATES OP RISK, OPPICIAl TELLS AAAS BOSTON-(By a BNA Staff Editor)--The Environmental Protection Agency's current tenfold overestimates of the cancer risks posed by exposure to chemicals would be reduced drastically under changes the agency is considering, an agency official told a symposium Feb. 12. Peter Preuss, director of EPA's Office of Technology Transfer and Regulatory Support, said the agency may change several of the major assumptions it uses to calculate the risks from exposure to chemicals. Risk assessment Is an evolving process, be said, and the changes under consider ation would refine the agency's calculations of risk. Preuss made the remarks during a symposium st the American Association for the Advancement of Science annual meeting. The modifications would be based on EPA research on how wall laboratory animal data predict human cancer risks, according to Preuss. Using both toxicologic informa tion and human epidemiology oats for 44 chemicals, the agency concluded that the use of animal data alone nvaraalk. mates the risk to humans on the average of tenfold, he said. Different Assumption* Under one change being considered, EPA would switch from its assumption that a person will be exposed to a eeruin chemical 24 hoars daily for 70 yean to an estimate that a person will be expoaed two to 16 hours per day for 10 to 36 years, according to Preuss EPA also Is mulling a change in how it calculates a substance's potency, Pnuss said. The environmental agency now givet equal weight to benign and malignant tumors found in experimental animals exposed to the chemical, he explained, but in the future might use only malignant can cers for risk assessment The agency also may use the average potency of the chemical, calculated from the results of toxicologic experi ments using a variety of animal strains, he Mid. EPA currently uses a number derived only from experiments using the most "sensitive" animals-the species or strain of laboratory animal that la moat likely to dovelop cancer from the substance. If these changes are adopted, the current tenfold overestl- matlon of the cancer risk to humans would drop to a twofold overestimation of risk, Preuss said. Carcinogens Predicted To to Less Haaardoua Bruce Ames, chairman of the biochemistry department at the University of California at Berkeley and Inventor of a widely used bacteria mutation asrey, told the seminar he expects that over the coming years, carcinogens will be .found to be far more common and much ItM hasardous than now thought. Ames said it is reasonable to assume chemicals that cause cancer In laboratory animals will cause cancer in humans-- but only in people who receive the unt high dose of the substances the animals got. Cancer is a degenerative disease of old age, for both laboratory rats and people, Ames seid. "Whatever is doing us In in aging Is doing us in in cancer," he seid. Regulators should be concerned with the carcinogenic potency of a subetanee, not the mere fact that it la carcino genic, he argued. By way of example, Ames said that regulation of trichloroethylene, a solvent he --Pe* a "very weak" carcinogen, does not make senso became the chemi cal is used in place of fieauneble solvents that pose e greater danger of death to workers. Roger McClellan, director and president of the Lovelace Inhalation Toxicology Research Institute in Albuquerque, N.M., told the symposium risk assessors need to understand how a chemical affects the body at low levels of exposure. Additionally, they need to understand bow various animal species, Including humans, an similar aqd how they differ in the way they metabolise substances, be said. PuMie tnvetvement In Risk Deeiaiens Erik Rifkin, head of the Columbia, Md., consulUng firm of Rlfkin and Associates, said members of the public who are exposed to carcinogens should play a part in deciding how their risks should be managed. The public should be involved with risk decisions from the beginning, he said. Regulators should not present a risk management proposal to people Just for their reaction. Although risk management decisions would become more tedious and difficult if the public were involved, people would understand the nuances of risk assessment that regu lators find difficult to explain, Rifkin said, and would accept compromises for risk management more readily. Laymen can understand risk assessment if scientists will give them the appropriate information, he added. Rifkin criticised regulatory agencies, environmental groups, and the chemical industry for giving the public "lip service" In risk assessment, rather then encouraging people exposed to carcinogens to participate in decision-making. Those making the decisions "think they know what's beat for the puMic," ha said To help communicate how great a risk is from certain exposures to e chemical, Rifkin suggested that regulators express risk not as a single number but as a range, thus incorporating uncertainty. He also sold consistent risk as sessment methods should be developed and used in all federal and state regulatory agendas. Responding to Rlfkln's presentation, Preuss sold EPA Is trying to decentralise risk management strategies. The agaocy is encouraging its 10 refiooal offices, as well as state and local governments, to make such risk management decisions using information gathered by the Emergency Planning and Community Rlght-To-Kaow Act, Preuaa said. PeefteMto ERA POLICY ON AGREEMENT! WITH INDUETWY TO AVOID CANCELLATION HEARING! HTT !Y JUOG! The Environmental Protection Agency must follow the letter of the federal pesticides law even If the agency believes that doing so will not be the beat way to protect human health and the environment, a federal lodge told agency lawyers Feb. 13 la a caee Involving an environmen tal group's challenge to EPA's actions on the tanmltiddes chlordane and heptacblor (NCAMP v. EPA, DC DC, No. 17- 2069). Howevsr. Judge Louis F. Oberdorfer oi the U.S. District Court for the District of Columbia did sot announce a J ) 2-1S-SS Copyright O IMS by Tho hnu of National Affairs, tne. 0tO-rorsfSl/so*.M CTL017448