Potentially hazardous substances in surface waters

Abstract

In this paper, some initial results of a monitoring program with respect to toxic substances in the river Rhine are presented together with experimental details on the analytical methods used. The results cover the period, September 1969–March 1972.

α-Benzenehexachloride (α-BHC), γ-BHC or lindane, and hexachlorobenzene (HCB) are nearly always present in the Rhine. The concentration of these substances in the river is about ten times as high as in typically “agricultural” surface waters. Endosulfan, an insecticide which had been found in the river Rhine in several “waves” during the years 1969 and 1970, has been rarely found in that river since July, 1970. The other organochlorine pesticides and their metabolites (heptachlor, -epoxide, aldrin, dieldrin, endrin and DDT-complex) have occasionally been found, but only in low concentrations. Polychlorinated biphenyls (PCB's) have not yet been found in detectable amounts, i.e. <0.5 μg/liter. Cholinesterase inhibitors are always present in the Rhine, and their occurrence is typical for the Rhine and its tributaries.