著者

片木 敏行 於勢 佳子

出版者

Pesticide Science Society of Japan

雑誌

Journal of Pesticide Science (ISSN:1348589X)

巻号頁・発行日

vol.40, no.3, pp.69-81, 2015-08-20 (Released:2015-08-20)

参考文献数

176

被引用文献数

6 48

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The toxic effects of pesticides on earthworms, one of the most important bioindicators in the terrestrial environment, are closely related to their body burden determined by uptake, metabolism and excretion processes. Not only the passive diffusion via the outer skin from a dissolved fraction of pesticide but also the ingestion of contaminated soil and food governs the uptake process, with each contribution controlled by either the hydrophobicity of the pesticide or the soil organic matter. Although the available information is limited, earthworms are likely to metabolize pesticides via hydrolysis and oxidation (Phase I) followed by conjugation (Phase II), and low bioaccumulation is observed as a result for most pesticides. The acute toxicity in the soil exposure can be partly explained by the dissolved fraction of pesticide in pore water, but the contribution of dietary uptake and metabolism should be further studied to correctly evaluate pesticide toxicity.

著者

宮本 貢 藤原 彰子 田中 仁詞 片木 敏行

出版者

日本農薬学会

雑誌

Journal of Pesticide Science (ISSN:1348589X)

巻号頁・発行日

vol.38, no.4, pp.173-180, 2013-11-20 (Released:2013-11-20)

参考文献数

37

被引用文献数

5

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Acute aquatic toxicity of eight major metabolites of the pyrethroid insecticide metofluthrin, potentially formed via oxidation and ester cleavage in the environment, was examined using three representative species, fathead minnow (Pimephales promelas), Daphnia magna and green alga (Pseudokirchneriella subcapitata). All metabolites showed a wide range of toxicity but were more than a hundredfold and tenfold less toxic than metofluthrin to pyrethroid-sensitive (fish and daphnid) and -insensitive (algal) taxa, respectively; 0.44 to >120 mg/L (fish 96-hr LC50), 6.3 to >120 mg/L(daphnid 48-hr EC50), and 2.6 to >110 mg/L (algal 96-hr EyC50). The structural modification via ester cleavage and/or oxidation was found to significantly control the acute aquatic toxicity of the metabolites. The decreased lipophilicity in the metabolites generally resulted in much less acute toxicity, the extent of which was dependent on an introduced functional group such as formyl as a toxicophore and carboxyl causing a higher acidity.

著者

小高 理香 菅野 輝美 片木 敏行 瀧本 善之

出版者

日本農薬学会

雑誌

日本農薬学会誌 (ISSN:03851559)

巻号頁・発行日

vol.27, no.3, pp.235-241, 2002-08-20

参考文献数

28

被引用文献数

2

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フェニトロチオン及びそのオキソン体のフランスの湖水及び日本の池水-底質系での好気的な代謝試験を行った.系への通気方法がフェニトロチオンの代謝経路に与える影響を見るために, 水層中に穏やかに通気するかまたは水表面上に空気を流す方法で実験を行った.いずれの方法においても代謝経路はほぼ同じであったが水-底質間の放射能分布に若干の違いが認められた.水中通気による嫌気雰囲気の減少から, フェノール体と二酸化炭素の生成量が増加し還元的代謝が減少した.フランスと日本の水-底質系でのフェニトロチオンの代謝に顕著な差異は認められず主にP-O-アリール結合の開裂によるフェノール生成, ニトロ基のアミノ基への還元とそれに続く.アセチル化により分解された.オキソン体の生成(<1%)は主要な分解経路ではなく, 速やかにP-O-アリール結合が開裂しフェノール体に分解された.