Monday, October 1, 2012
Rachel Carson: Reacting to Experts
Rachel Carson: Reacting to Experts: Much to the American chemical industry's dismay, Carson published Silent Spring in 1962. Trained as a marine biologist, she voiced concern about the effects of DDT (and Dieldrin) on birds and fish (anything that laid eggs). Throughout the 1940s and 1950s, DDT and Dieldrin were widely used by American farmers as insecticides. They especially killed fire ants, gypsy moths, lice and mosquitoes (which carried diseases like typhus and malaria). In fact, these insecticides proved so effective that the United States Department of Agriculture (USDA) ("the experts") began large-scale aerial spraying programs over American farmlands. Carson believed the potential downsides (long-term consequences) of these insecticides had not been properly studied. Having worked for the U.S. Bureau of Fisheries, she witnessed the negative impact of DDT firsthand. And because birds and fish were turning up dead in areas that received aerial spraying, the Kennedy administration's Interior Secretary Stewart Udall began to pay serious attention to the controversy that Silent Spring had caused. But the mammalian toxicity of DDT was actually quite low, as its effects on humans were not overly noxious. The primary problem with DDT was its bio-accumulation, which meant it remained in the soil (and sat on crops as a residue). Therefore, Congress banned DDT in 1972, yet other insecticides with lower bio-accumulations simply replaced it.