DDT

is an , first synthesized in 1874 by . In 1939 discovered that DDT is an effective . In WW II, from 1943 to 1945, DDT was used to kill mosquitos and lice to effectively limit the spread of and . In the 1950s and 1960s, DDT was widely used to control insects. However, DDT is a — harmful to birds and mammals and readily by s and s. During the 1970s and 1980s, many countries banned the agricultural use of DDT.