Pesticides represent an important economic commodity and a very broad class of chemicals. Each year massive amounts of pesticides are produced industrially and are used in agriculture and forestry, as well as in and around the home. Survey projections indicate that the worldwide market for pesticides this year will be close to $10 billion (Anonymous, 1977). Accumulating evidence suggests that pesticides pervade our environment so extensively that the likelihood of accidental exposure in many urban areas is about equal to that in rural farming communities. The U.S. Environmental Protection Agency estimates that each year over 45,000 persons in the U.S. are poisoned by pesticides (Pimentel and Pimentel, 1979), and the World Health Organization estimates that worldwide there are more than 500,000 poisonings each year, with mortality in excess of 1% (WHO, 1973). Pesticides are therefore widespread and widely used in our environment and consequently are an important topic in any discussions about environmental quality and public health.