Introduction

D d t was first created in 18 74, but its insect killing properties were not discovered until 19 39. It was also called the insect bomb in world war two for its ability to control malaria among troops by killing mosquitoes on contact. But an american biologist started to notice that d d t had some less desirable effects. So in 19 62, rachel carson published a book titled silent spring. She declared in no uncertain terms that pesticides were harming human and animal life, in part er birds. The title of her book referred to a spring in the not too distant future where there would be no bird songs because of d d t. This is one of the nation's best seller fir