Don pesticides usually disappear once they are applied?
Many pesticides do break down rapidly in the environment, but others – like DDT and dieldrin – can remain toxic for 20 years or longer, continuing to kill insects and harm other organisms. The breakdown products of some pesticides – aldicarb and malathion, for instance ? can be more toxic than the parent compound. Under the hot and humid conditions found in many Third World countries, persistent pesticides apparently break down more quickly, but bioaccumulation can still take place. • Is our drinking water pesticide-free? Until pesticide residues started turning up in drinking water wells, most people believed groundwater was protected from contamination by soil and rock formations. By 1986, a total of 19 different pesticides applied in agriculture had been detected in groundwater in 24 out of the U.S.’s 50 states. Some towns must bring in bottled water from other sources because their communities drinking well is contaminated. • Aren’t pesticides only a problem in areas where the chem
