Factors affecting the bioconcentration of hexachlorocyclohexanes in early life stages of oncorhynchus mykiss

A commercial mixture of ?-, ?-, ?-, and ?-hexachlorocyclohexane (-HCH) isomers has been tested for bioconcentration on early life stages of Oncorhynchus mykiss. Experimental results were elaborated by means of BIOCON, an interactive program for personal computers that provides bioconcentration factors (BCFs) and kinetic uptake and depuration coefficients as well as their standard deviations. The comparisons performed on a statistical basis evidenced few differences among the bioconcentration capability of larval stages, contrary to what was observed in previous studies with other chemicals. In the early juvenile stage, ?- and ?-HCH are characterized by higher BCFs than the ?-isomer. The role of lipids is also investigated. The total lipid content seems to play a major role in influencing bioaccumulation parameters but cannot thoroughly explain BCF variability, which must be ascribed to other factors such as life stage and lipid composition.