Bioaccumulative Pesticides

Many organochlorine pesticides phased out since substantial use
began in the
1960's have properties that result in their increased
accumulation up the food
chain (bioaccumulation). Dichlorodiphenyl trichlororethane
(DDT), dieldrin, and
toxaphene are bioaccumulative pesticides that are no longer in
use in the
United States, but persist and are still detected in the
environment. Exposure
to bioaccumulative pesticides can affect nervous, reproductive,
and immune
system function. In addition, the U. S. Environmental
Protection Agency (EPA)
classifies most organochlorine pesticides as probable human
carcinogens.
Minnesota has Water Quality Standards for DDT, dieldrin, and
toxaphene, which
are measured in water in units ranging from nanograms (one
billionth of a
gram) per liter (ng/L) to picograms (one trillionth of a gram)
per liter (pg/L).