m47.    When did we begin using pesticides?

First generation insecticides were recorded in 500 B.C. (sulfur) and used into the 15 century when arsenic, lead, and mercury (still in soils today) were discovered to be effective. In the 17^th century, nicotine sulfate from tobacco leaves were used to control insects. In the 18^th century, chrysanthemum flowers and derris plant roots were used. For hundreds of years folks have used red pepper, garlic, and lemon oils to control pests. DDT was the first man-made insecticide. Around the world, 2.3 million metric tons are used yearly, or 1 pound per person.

e15.    What was early life like?

e19.    What materials can cause water pollution?

e20.    What are environmental hazards and risks?

g19.    Where do you find air pollution?