Industry viewpoint on thresholds for genotoxic carcinogens

Modern chemical control of pests has contributed to a dramatic improvement in public welfare since its introduction 50 years ago. Millions of lives ha ve been saved through the control of disease vectors. and millions more hav e been improved by the use of chemicals to produce an inexpensive and abund ant food supply. Hundreds of pesticidally active ingredients are in commerc ial use today, and among these are found genotoxic and nongenotoxic carcino gens. In the United States. the Environmental Protection Agency regulates c arcinogens using threshold and nonthreshold approaches depending upon the o utcome of a weight-of-evidence determination. More than one-half of all pes ticides with some evidence of carcinogenic potential are regulated by the n onthreshold approach. The limitations on product use imposed by this approa ch have restricted the number of products available to growers and to the p ublic. This restriction has had a direct impact on industry with respect to commercial success and financial returns on investment as well as an indir ect impact on the industry's ability to fund the discovery and development of new compounds. This paper explores the question of how well regulation b y the nonthreshold approach has achieved the goal of protecting public heal th, whether it does this better than the alternative use of the threshold a pproach, and whether the incremental protection it affords is a meaningful public benefit that justifies the aforementioned impacts on industry.