Possible teratogenic and carcinogenic effects of pesticides on human health are discussed. A study of cancer and adverse reproductive outcomes among floriculture workers in Bogota, Colombia, is described. There are approximately 13,000 floriculture workers exposed to pesticides in Bogota. More than half of these are females, most of whom are of child bearing age. The number of cancer outcomes was found to be small; however, almost 600 infants with major malformations were found. It is noted that the floriculture industry in Bogota uses around 100 pesticides, fungicides, nematocides, and similar substances. Studies of captan (133062), the primary fungicide used in Bogota, are discussed. Captan was also chosen for study because one of its metabolites has a structure that resembles thalidomide. Approximately 24,000 kilograms per year of captan are used. Studies of captan metabolism in rats are described. Rats were administered captan at a dose of metabolites was investigated. All captan metabolites were completely excreted within 8 hours of dosing. Around 5 percent of the dose was excreted as unchanged captan. No captan was found in adipose tissue or sera. It is concluded that pesticide spraying poses serious problems to humans. A case of organophosphate poisoning in United States Department of Agriculture inspectors at Miami International Airport (Florida) who were poisoned merely by opening boxes of sprayed plants is also mentioned.