ABSTRACT
I. INTRODUCTION Recent estimates are that at least 70,000 chemicals are in commerce (Fagin et al., 1996). About 12,800 chemicals are manufactured in quantities of more than 1 million lb/year (U. S. Congress, 1985) and 50 of over 1 billion lb (Bergin and Grandon, 1984). The statistics do not end here: More than 35,000 pesticides are registered with the U. S. Environmental Protection Agency (EPA), some 3600 food additives are approved for use by the U. S. Food and Drug Administration (FDA), and more than 1500 chemicals are listed as common ingredients in cosmetics (Lowrance, 1976). Over 1200 additional compounds are incorporated into countless household products. In 1995 alone, the 100 largest U. S.-based chemical manufacturers sold more than 234 billion dollars worth of chemical products. Even the food we eat and the water we drink is suspect: About 1% of domestically grown and 3% imported food contain illegal residues, and more than 700 contaminants, including pesticides, solvents, metals, and others, have been found in public drinking water (Jacobson et al., 1991). Each year, the average American consumes about 9 lb (4.1 kg) of chemical additives other than sugar and salt (Epstein, 1978). These stark figures demonstrate convincingly that we are exposed to a bewildering array of chemicals.
