Distribution and elimination of hexachlorobenzene, octachlorostyrene and decachlorobiphenyl in rainbow trout, Salmo gairdneri

In two experiments rainbow trout, Salmo gairdneri, were injected intraperitoneally with an oil solution containing hexachlorobenzene (HCB) and octachlorostyrene (OCS), or a mixture of chlorinated hydrocarbons extracted from fish in a contaminated area. HCB and OCS were determined by gas chromatography in fat, liver and muscle, and decachlorobiphenyl (DCB) was determined in fat. The water temperature was 7°C and both experiments lasted for 37 wk. In most cases significant correlations were observed between the logarithm of the concentrations of HCB, OCS and DCB, and time from the start of the experiment. The fish increased their body weight during the experiments. Therefore a simple correction of the concentrations was accomplished. From the weight-corrected concentrations the apparent half lives were calculated to be: HCB in liver, 81 days; OCS in liver, 143 days; and HCB in fat, 146 days. In fat the weight-corrected concentrations of OCS increased with time. The biological half life was calculated to be of the order of 60–70 days for HCB and 90–120 days for OCS. The elimination of OCS in rainbow trout at 7°C seems to be slightly lower than in the rat.