Abstract |
Analysis of 1,549 water samples shows that the Red Cedar River, Michigan, is highly contaminated with DDT and DDT metabolites (TDE and DDE). The river becomes progressively more contaminated in a downstream direction and shows seasonal variations. Pesticides in bottom samples show the amount of long term contamination, whereas those in the suspended matter (that retained by a 5 micron filter) show the amount of pesticide being carried on a short term basis. The largest amount of pesticide contamination entering the Red Cedar River comes through waste water treatment plants. (WRSIC abstract) |