海産魚を用いる有害化学物質の生物濃縮試験法の確立に関する研究 ＩＩ 試験魚の大きさによるα‐ヘキサクロロシクロヘキサンの生物濃縮特性の変化

Abstract

Experiments on bioconcentration and elimination of α-hexachlorocyclohexane (α-HCH) were carried out by using six sizes of Sillago japonica ranging from 0.59 to 10.45g, five sizes of Pagrus major ranging from 1.25 to 9.87g and two sizes (0.16 and 0.34g) of Rudarius ercodes. Changes of bioconcentration factor (BCF), uptake rate constant (k1) and elimination rate constant (k2) caused by an increase in body weight of these fish species were studied. k2 declined with an increase in body weight of three fish species. On the other hand, BCF, which is expressed as k1/k2, did not change with an increase in body weight of these fish. These results suggested that k1 as well as k2 depends on the size of fish and declines with an increase in body weight, and also suggested that the size of fish is not an important factor in the determination of BCF. The present study indicated that a suitable body weight of test fish for the bioconcentration experiment is 2-5g for S. japonica and 2-10g for P. major, and that the size of test fish should be selected exactly in experiments on the kinetics of uptake and elimination of hazardous chemicals.