MONITORING OF MUTAGENICITY IN AQUATIC BIOTA AS A TECHNIQUE FOR THE ENVIRONMENTAL ASSESSMENT

在濑户内海沿岸的5个沿着采集贻贝，用丙酮-乙腈提取其可食部分。提取液经蓝人造丝（BR）处理后，用鼠伤寒沙门氏菌YG 1024进行致突变性分析，用高效液相色谱-荧光法（HPLC-F1）进行苯并（a）芘（BaP）的检测，结果表明，49个贻贝样品中有8个样品的BaP含量大于1.0ng/g，29个样品中有17个样品的BaP含量大于1.0ng/g，回复突变体数超过溶剂对照的3倍。各组BaP水平与致突变性呈正相关。在采集贻贝的同一地点，将蓝色人造丝在海水中饥饿24小时。用甲氨酰缩合法制备了苯并（a）芘（BaP），并测定了其致突变性. 1g当量BR中苯并（a）芘的含量为0.05 ~ 19.5ng，29份样品中有17份呈阳性。再次观察到BaP的量与致突变性之间呈正相关。为了鉴定致突变性的组分，我们通过C18柱用HPLC分离贻贝和BR的样品提取物，并测定每个组分的致突变性。在贻贝的情况下，在极性组分中观察到的致突变性高于含有BaP的组分。此外，在水族箱中对日本蚬（Corbicula japonica）进行了0.058-0.224 ng/ml的BaP暴露实验。在12和24小时后，在极性组分中再次观察到升高的致突变性，但是双壳类积累的BaP水平仅比水族箱中高11-38倍。上述结果表明，监测生物群样品中的致突变性将提供一种潜在的方法，在水生环境中的致癌物质。

Mussels were harvested at 5 selected sites along the coast of Seto Inland Sea and their edible parts were extracted with acetone-acetonitrile. The extract was then subjected to blue rayon (BR) treatment and the sample thus prepared was analyzed for mutagenicity with Salmonella typhimurium YG1024 and for benzo(a)pyrene (BaP) with HPLC-Fl. Eight out of 49 mussel groups contained BaP more than 1.0 ng/g and 17 out of 29 group showed positive results, the number of revertants exceeded 3 times more than that of solvent control. A positive correlation was observed between the level of BaP and the mutagenicity in individual groups. Blue rayon was hunged for 24 hr in the sea water at the same sites where mussels were collected. The eluate with methanoammonia was condensed and also assayed mutagenicity and BaP content. The eluate from 1g equivalent BR contained 0.05 to 19.5 ng of BaP and 17 out of 29 samples showed positive results. Again a positive correlation was observed between the amount of BaP and the mutagenicity. In order to identify the attributable components to the mutagenicity, we fractionated sample extract from mussel and the eluate from BR through C18 column with HPLC and assayed mutagenicity in each fraction. In case of mussel, elevated mutagenicity was observed in the polar fraction than that contained BaP. Further Yamato-shijimi, Corbicula japonica, was experimentally exposed to BaP at 0.058-0.224 ng/ml in an aquarium. After 12 and 24 hr, an elevated mutagenicity was again observed in the polar fraction, however the bivalve accumulated merely 11-38 times higher level of BaP than that in the aquarium. The above results suggest that a monitoring of mutagenicity in biota samples will provide a potential approach to carcinogenic substances in the aquatic environment.