eerie Ane Us eG) Nie 0) Lidia) Eee ten 11 
Most Everything You Wanted to Know 
About Chlorinated Hydrocarbons 
(But Were Afraid to Ask the Manufacturers) 
Compiled by MRS. LEE JENS 
Chairman, Pesticides Committee 
Illinois Audubon Society 
Chlorinated hydrocarbons move through the environment by water run- 
off, volatization from soil, co-distillation with water and on dust particles 
and the food chain. They are persistent and do not break down in years 
(except for methoxychlor). Insects become resistant to them, but preda- 
tors (including man) do not. When insects become resistant, the problem 
is worse than ever because the predatory and parasitic enemies of the 
pest have been destroyed by the pesticides. Chlorinated hydrocarbons 
are nerve poisons. The liver’s enzymes which are produced to detoxify DDT 
have an unfavorable effect on the body’s hormones, such as thinner egg- 
shells in bird’s eggs. Chlorinated hydrocarbons simplify the biotic com- 
munity making it much less stable and much more given to outbreaks of 
pests—nature’s balance is disrupted seriously. They have done great dam- 
age to valuable wildlife. Long term effects on man have not been adequat- 
ely studied. Ecologists are worried about possible effect on soil organisms 
responsible for the nitrogen cycle essential to life on earth. They are non- 
selective. 
DDT: The best known of the chlorinated hydrocarbons. Stored in fat of 
bodies and in organs high in fatty substances, including adrenal glands, 
kidneys, liver and thyroid gland. Builds up to quite high levels. Scientists 
do not agree on how high. Found in bodies all over the world, even where 
there has been no treatment for great distances. Passes from one creature 
to another by food chain. Turns up in milk of man and other animals. 
Minute quantities reduce photosynthesis in ocean aglae which jis source of 
half our oxygen. Believed to be responsible for the serious decline in some 
kinds of wildlife such as the bald eagle. 
Dieldrin: The next best known of the chlorinated hydrocarbons. As is DDT, 
dieldrin is found all over the world. It is five times more toxic than DDT 
to vertebrates when swallowed and forty times more toxic when absorbed 
through the skin in solution. It has caused appalling destruction of wild- 
life. 0.5 to 1.5 lbs. per acre killed all rodents and rabbits. Only 0.2 lbs. per 
acre killed all birds. Used in Japanese beetle programs extensively. 
Aldrin: Like dieldrin, aldrin is extremely toxic. It changes to dieldrin in 
residue. A quantity only as large as an aspirin tablet can kill 400 quail. 
Even at one ounce per acre, one square foot is toxic enough to kill one 
quail adult or 16 juvenile quail Also used extensively in large scale Japan- 
ese beetle programs. 
Endrin: Most toxic of the chlorinated hydrocarbons. Five times as poisonous 
as dieldrin. 
Heptachlor: Has especially high capacity for storage in fat. Four times as 
toxic as DDT. Residues in soil change to heptachlor epoxide which is four 
