Environmental quality and safety最新文献_第6页

Degradation of organophosphorus pesticides in soils with special reference to unaerobic soil conditions. 有机磷农药在土壤中的降解，特别是在非需氧土壤条件下。

Environmental quality and safety Pub Date : 1975-01-01

C Tomizawa

{"title":"Degradation of organophosphorus pesticides in soils with special reference to unaerobic soil conditions.","authors":"C Tomizawa","doi":"","DOIUrl":"","url":null,"abstract":"Organophosphorus pesticides are generally transformed by the reactions including oxidation, reduction, hydrolysis, hydroxylation, dehydrochlorination, dealkylation, methylation, isomerization, and conjugate formation. Although the degradation process of pesticides in soils is complicated, main factors may be soil constituents, soil microflora, and chemical structures of pesticides. Chemical structures are especially important for soil metabolism of organophosphorus pesticides, because the priority of the reactions mentioned above is decided. Although organophosphorus pesticides are generally hydrolyzable, the order of hydrolysis varies with chemical structures. It might be said that the slower the hydrolysis rate of the molecule, the more the possibility to be attacked by reactions other than hydrolysis. In such cases, oxidation and reduction are primarily important for the degradation of organophosphorus pesticides. Flooded soils in paddy fields give a favourable environment for the reduction of organophosphorus pesticides having labile substituents such as nitro groups. The threshold of reduction in-flooded soil is expressed as redox potential. Eh, the Eh of paddy soil fluctuates to a great extent, depending on seasons and soil types, especially organic matter content. The result of laboratory experiments with fenthion, disulfoton, Kitazin P (0,0-diisopropyl S-benzyl phosphorothiolate), edifenphos (0-ethyl S,S-diphenyl phosphorodithiolate) and amiprophos (0-ethyl 0-(2-nitro-p-tolyl) N-isopropyl phosphoramidothionate) suggested the participation of several factors mentioned above in the degradation of organophosphorus pesticides.","PeriodicalId":75827,"journal":{"name":"Environmental quality and safety","volume":"4 ","pages":"117-27"},"PeriodicalIF":0.0,"publicationDate":"1975-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12369896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Transformation of carbamate insecticides in the environment. 氨基甲酸酯类杀虫剂在环境中的转化。

Environmental quality and safety Pub Date : 1975-01-01

J Miyamoto

引用次数: 0

Environmental problems related to herbicidal use in Japan. 日本除草剂使用的环境问题。

Environmental quality and safety Pub Date : 1975-01-01

S Matsunaka, S Kuwatsuka

引用次数: 0

Inhibition of hepatic drug-metabolizing enzymes by thiophaophate insecticides and its toxicological evaluation. 硫磷类杀虫剂对肝脏药物代谢酶的抑制作用及其毒理学评价。

Environmental quality and safety Pub Date : 1975-01-01

M Uchiyama, T Yochida, K Homma, T Hongo

{"title":"Inhibition of hepatic drug-metabolizing enzymes by thiophaophate insecticides and its toxicological evaluation.","authors":"M Uchiyama, T Yochida, K Homma, T Hongo","doi":"","DOIUrl":"","url":null,"abstract":"Thiophosphate insecticides, fenitrothion, diazinon and methylparathion, inhibit hepatic drug-metabolizing enzyme activity which was assayed using aminopyrine and aniline as substrates. About 50% inhibition was observed 4 hrs after the injection of fenitrothion into mice in a dose of 25 mg/kg. The addition in vitro of thiophosphates into a reaction mixture of drug metabolizing enzyme also produced an effective inhibition and IC50 was around 10(-5)M for fenitrothion. DDVP and oxygenated metabolite of fenitrothion did not show any inhibiting effect either in vitro or in vivo. The inhibition of thiophosphates in vitro was competitive while the kinetics of in vivo inhibition was shown as non-competitive. The drug metabolism in the rat liver preparation was also inhibited by thiophosphate in vitro, but in vivo treatment to male rats resulted in only slight inhibition. Female rats exhibited the similar response as mice. The administration of fenitrothion to mice prolonged the hexobarbital sleeping time and, consequently, suppressed the oxidative metabolism of parathion in liver preparation. These effects reveal that the biological half life of thiophosphate insecticides could be altered by the mode of administration or by co-existing thiophosphates.","PeriodicalId":75827,"journal":{"name":"Environmental quality and safety","volume":"4 ","pages":"109-16"},"PeriodicalIF":0.0,"publicationDate":"1975-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12369895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0