By
1974, total freon production in the world was about 2 billion pounds
annually Most freon, even that used in refrigeration, eventually makes
its way into the atmosphere where it diffuses unchanged into the
stratosphere In stratosphere, freon is able to initiate radical chain
reactions that can upset the natural ozone balance DDT, the first chlorinated organic insecticides, was originally prepared
in 1873, but it was not until 1939 that Paul Muller of Geigy
Pharmaceuticals in Switzerland discovered the effectiveness of DDT as
an insecticide