Mochida Kazuhiko, Ito Katsutoshi, Harino Hiroya, Kakuno Akira, Fujii Kazunori
National Research Institute of Fisheries and Environment of Inland Sea, Fisheries Research Agency, 2-17-5 Maruishi, Hatsukaichi, Hiroshima 739-0452, Japan.
Environ Toxicol Chem. 2006 Nov;25(11):3058-64. doi: 10.1897/05-688r.1.
We evaluated the median lethal concentrations (LC50s) of the pyrithione (PT) antifoulants copper pyrithione (CuPT) and zinc pyrithione (ZnPT) to a teleost, red sea bream (Pagrus major), and a crustacean, toy shrimp (Heptacarpusfutilirostris). The 96-h LC50 values of CuPT and ZnPT, on the basis of actual concentrations, were 9.3 and 98.2 R.g/L, respectively, for red sea bream and 2.5 and 120 microg/L, respectively, for toy shrimp. Histological observations revealed that the secondary lamellae of the gill filaments of the experimental fish were heavily damaged after exposure to the PTs, suggesting that fatal hypoxemia was one cause of death. Because CuPT and ZnPT are usually used in combination with Cu, we also estimated the joint toxicities of the PTs with Cu using the LC50 values of the PTs and those of Cu (84.4 and 113 microg/L for red sea bream and toy shrimp, respectively). The results suggested that the joint toxicity of the ZnPT and Cu mixture is more than the additive toxicities of CuPT and Cu, especially in toy shrimp. The enhancement of toxicity in the mixture was inferred to be caused by conversion of ZnPT to the more toxic CuPT in the presence of Cu.
我们评估了吡啶硫酮（PT）类防污剂吡啶硫酮铜（CuPT）和吡啶硫酮锌（ZnPT）对硬骨鱼真鲷（Pagrus major）和甲壳类动物日本沼虾（Heptacarpus futilirostris）的半数致死浓度（LC50）。基于实际浓度，CuPT和ZnPT对真鲷的96小时LC50值分别为9.3和98.2μg/L，对日本沼虾分别为2.5和120μg/L。组织学观察表明，实验鱼鳃丝的次生薄片在接触PTs后严重受损，这表明致命的低氧血症是死亡原因之一。由于CuPT和ZnPT通常与铜联合使用，我们还利用PTs和铜（真鲷和日本沼虾的LC50值分别为84.4和113μg/L）的LC50值估算了PTs与铜的联合毒性。结果表明，ZnPT与铜混合物的联合毒性大于CuPT与铜的相加毒性，尤其是在日本沼虾中。混合物中毒性增强被推断是由于在铜存在下ZnPT转化为毒性更强的CuPT所致。
