Kinetics of bioaccumulation and clearance of isomeric hexachlorocyclohexanes

Bioaccumulation experiments were performed on the hexachlorocyclohexane isomers alpha-HCH, beta-HCH, gamma-HCH and delta-HCH, testing them simultaneously. Bioaccumulation factors (BCFs) were calculated from the uptake rate constant (k1) and the clearance rate constant (k2) as: BCF = k1/k2. The BCFs of alpha-HCH (1100 +/- 175) and gamma-HCH (920 +/- 131) were similar. The BCFs of beta-HCH (1520 +/- 276) and delta-HCH (1640 +/- 269), also similar, were significantly higher than those of the alpha- and gamma-isomers.