拟除虫菊酯类农药的免疫毒性研究进展

拟除虫菊酯类杀虫剂因其高效、对哺乳动物低毒和易降解等特性已被广泛使用,目前对其生态毒理学的研究主要集中在神经及内分泌干扰、发育和生殖毒性方面,而关于其免疫毒性的研究也越来越受到了关注。文章对拟除虫菊酯类农药的免疫毒性及其分子机制研究进展进行了总结,主要从免疫器官、免疫细胞、免疫分子和免疫功能等方面综述了此类杀虫剂对不同生物的免疫毒性及其可能的分子机制,同时总结了拟除虫菊酯类杀虫剂暴露与免疫相关疾病发生的关联,以期为拟除虫菊酯类农药免疫毒性的进一步探究提供参考。     

试论拟除虫菊酯类农药在水稻田中的应用

拟除虫菊酯类农药具有高效、广谱、残留较低等特点,但由于其对鱼类等水生生物毒性高,以及可能导致稻飞虱再猖獗等原因,我国禁止其在水稻田使用。本文论述了拟除虫菊酯类农药在稻田使用时对水生生物的毒性、稻飞虱再猖獗、害虫抗药性和天敌的影响,并对拟除虫菊酯类农药在水稻田中使用的可行性提出了建议。     

气相色谱法分析拟除虫菊酯类农药简介

近年来国产拟除虫菊酯类农药如戊酸氰醚酯(S-5602)、戊酸醚酯(S-5439)、二氯苯醚菊酯,进口的拟除虫菊酯类农药如溴氰菊酯、氯氰菊酯、百树菊酯、氟氰菊酯、戊酸氰醚酯等,均有一定的数量。因此检定拟除虫菊酯类农药的质量是一个新课题。     

菊酯类农药对水田生物影响研究进展

拟除虫菊酯类农药是一个重要的杀虫剂类别,对有害昆虫具有良好的触杀作用.但是,在中国一直被禁止应用于水田害虫防治.本文综述了菊酯类农药对各种水田生物的急性和慢性作用机制、影响因子,提出拟除虫菊酯类农药能否在水田应用需要进行深入系统的研究论证.     

菊酯类农药在稻田使用初探(二)——拟除虫菊酯类农药在稻田使用的环境安全性研究

本文研究拟除虫菊酯类农药在稻田使用对水生生物、天敌、稻飞虱再猖獗以及对施药人员健康的影响 ,并研究菊酯类农药在作物和土壤中的残留 ,从而评价拟除虫菊酯类农药在稻田使用对环境的安全性     

拟除虫菊酯农药在茶园应用的安全性评价

采用田间模拟施药与气相色谱法研究了７种拟除虫菊酯在茶园生态环境中的降解动态,茶叶加工过程中的消解和泡茶过程中浸出率及其主要影响因子。根据实验结果推算出通过饮茶进入人体的农药量,结合农药的毒理特性,对拟除虫菊酯在茶园生态环境中应用的安全性进行了综合评价。结果表明,拟除虫菊酯类农药在茶园中应用的安全性显著高于有机磷农药,在拟除虫菊酯农药之间,其安全性也有较大差异。本研究不仅为茶园用农药的选择提供了依据     

菊酯类农药在稻田使用初探（二）——拟除虫菊酯类农药在稻田？…

本文研究拟除虫菊酯类农药在稻田使用对水生生物、天敌、稻飞虱再猖獗以及对施药人员健康的影响,并研究菊酯类农药在作物和土壤中的残留,从而评价拟除虫菊酯类农药在稻田使用对环境的安全性。     

加强对八氯二丙醚管理势在必行

1背景八氯二丙醚(octachlorodipropyl ethers又称S-421,S-2)是1959年由BA SF和日本Sankyo公司开发而成[1]。是广谱性增效剂,由于效果好,价格低廉,对拟除虫菊酯类、氨基甲酸酯类和有机磷类农药均具有增效作用。我国从上世纪80年代起将其与拟除虫菊酯类农药一起用于蚊香,其目的是     

使用拟除虫菊酯类农药十注意

使用拟除虫菊酯类农药十注意周伯瑜周枫（湖北孝感师专４３２１００拟除虫菊酯类农药杀虫效果比天然除虫菊好，药性较稳定，药效期也较长，受到农户的欢迎。属于拟除虫菊酯类农药种类较多，常用的有氰戊菊酯（速灭杀丁）、溴氰菊酯（敌杀死）、氯氰菊酯（灭百可）、氟氯氰...     

拟澳洲赤眼蜂对拟除虫菊酯类农药抗性比较试验

广东省利用赤眼蜂防治甘蔗螟虫,从五十年代开始就建立了赤眼蜂站,防治螟虫效果良好,防治面积不断扩大。拟除虫菊酯类杀虫剂是近年来发展起来的一类杀虫效果高对人畜毒性较低的农药。这类农药使用广泛,但如果多年连续使用,容易使某些害虫产生抗药性。我们在实验室用目前几种较常用的杀灭菊酯、中西除虫菊酯等对拟澳洲赤眼蜂卵期进行处理,不断提高药液浓度,了解赤眼蜂是否对拟除虫菊酯类农药产生抗性?以祈为抗性天敌的改良、遗传提供依据。     

Unusual features of the toxic action of dimethoate on Periplaneta americana and their causes

Dimethoate and its oxygen analog dimethoxon take more than six times longer than diazoxon (whose speed of action is more typical of organophosphorus insecticides in general) to cause irreversible symptoms of poisoning in cockroaches, although all are equally toxic to the insects if enough time is allowed. Dimethoxon was 200 times less active than diazoxon, both against cockroach cholinesterase and in electrophysiological tests against the central nervous systems of cockroaches. Other tests established that neither restricted penetration into the nervous system nor detoxication within it contributed to the weak neurotoxicity of dimethoxon. This weak neurotoxicity is compensated for by relatively high stability to detoxication, enabling dimethoxon to persist long enough within insects to achieve high overall toxicity and explaining why its overal toxicity is similar to that of diazoxon, which is more rapidly detoxified by the insects.     

Acute and delayed neurotoxicity of leptophos analogs

Nineteen O-halogenated-phenyl O-methyl phenylphosphonothionates were evaluated for acute toxicity (LD₅₀) to the female house fly Musca domestica L. and to the male Swiss white mouse, and for delayed neurotoxicity to the White Leghorn hen. The electron-withdrawing power of the phenyl substituents (Σσ^? values) correlate with the LD₅₀ values to house fly and mouse, with departures from linearity attributable to the steric hindrance of di-ortho-Cl substitution and by variations in the accessibility of the anionic site of acetylcholinesterase in the two species. The relationship with delayed neurotoxicity is less predictable although it clearly depends on suitable electron-withdrawing capacity. Delayed neurotoxicity also relates to a high degree of lipophilicity and prolonged residence time of the inhibitor in the nerve axon.     

The toxicity of cyromazine to Chironomus zealandicus (chironomidae) and Deleatidium sp. (leptophlebiidae)

The toxicity of cyromazine and a commercial formulation, ‘Vetrazin’®, to Chironomus zealandicus (thummi) Hudson and Deleatidium sp. was investigated. Under acute test conditions, the LC₅₀ values for each species were quite comparable. For C. zealandicus, the value varied according to instar, 100–400 mg litre^?1 for second- and third-instar to 1000–10000 mg litre^?1 for older fourth-instars. For the one size class of Deleatidium tested (c.10 mm long), the value was 300–400 mg litre^?1. High control mortalities of C. zealandicus limit that species' usefulness as an acute bioassay candidate. Under chronic test conditions, cyromazine showed a high toxicity to eggs or early-instar larvae of C. zealandicus. The maximum acceptable toxicant concentration for cyromazine against C. zealandicus was approximately 17.5 μg litre^?1. The possibility of water contamination at this level is discussed. Whole-of-life chronic tests with C. zealandicus indicated that the most susceptible stage was in the egg or soon after larval emergence. These results highlight the dangers of using short-term acute toxicity results to formulate environmental exposure limits for modern pesticides that do not have dysfunction of the nervous system as their mode of action.     

Inhibition of neurotoxic esterase and acetylcholinesterase by organophosphorus compounds in selected ectothermic vertebrates

The sensitivity of brain acetylcholinesterase and neurotoxic esterase to inhibition by several organophosphorus compounds was studied in selected ectothermic vertebrates. These enzymes are associated with organophosphorus compound acute and delayed toxicity, respectively. In addition, the susceptibility of several of these species to delayed neurotoxicity induced by organophosphorus compounds was studied. Larvae of the gray treefrog, Southern leopard frog, and narrow-mouthed toad were exposed dermally to tri-o-tolyl phosphate or phenyl saliginen cyclic phosphate (PSCP); no symptoms of delayed neurotoxicity were observed in any of these animals up to 2 weeks after metamorphosis. No symptoms of delayed neurotoxicity were seen in juvenile bullfrogs exposed to multiple ip doses of PSCP. The specific activity of neurotoxic esterase was highest in the larval bullfrog, with juvenile channel catfish and adult mosquitofish demonstrating intermediate levels. The larval Southern leopard frog, adult Northern leopard frog, juvenile green treefrog, and adult marine toad exhibited extremely low activities. The specific activity of acetylcholinesterase was highest in the juvenile channel catfish. Neurotoxic esterase in the larval bullfrog was more sensitive to organophosphate inhibition than that in either fish. PSCP was a more potent neurotoxic esterase inhibitor than leptophos-oxon. The juvenile channel catfish had the acetylcholinesterase most sensitive to organophosphate inhibition. Under the conditions tested, no evidence of in vivo sensitivity to the organophosphate-induced delayed neurotoxicity phenomenon was observed.     

丁香菌酯对平突船卵溞的毒性效应

丁香菌酯是中国自主研发的甲氧基丙烯酸酯类杀菌剂，为明确其对水生生物的毒性，本研究采用半静态试验法，分别检测了丁香菌酯对平突船卵溞的急性和慢性毒性。急性毒性试验结果表明，丁香菌酯对平突船卵溞的48 h-EC₅₀值为202 μg/L，属于高毒；慢性毒性试验结果表明，丁香菌酯对平突船卵溞初次产溞时间、产胎数、单雌产溞数及21 d体长等指标均有显著影响，对初次产溞数和蜕壳数影响不显著，以繁殖量为指标，其无可观察效应浓度 (NOEC) 为0.22 μg/L，最低可观察效应浓度 (LOEC) 为 0.67 μg/L。研究表明，丁香菌酯胁迫对平突船卵溞的生长和繁殖有一定的抑制效应。该结果可为合理评价丁香菌酯对水生生态系统的风险提供参考。     

手性农药毒性机制的对映体选择性

综述了手性农药在急性毒性、慢性毒性、细胞毒性、藻类与植物毒性及生物体富集方面的对映体选择性差异。大量研究显示,手性农药的不同对映异构体对于非靶标作用体的毒性存在显著差异,这种选择性差异既取决于手性农药的对映异构体,同时又与作用的受体相关。探讨了手性农药毒理学研究的重点和发展方向——在对映体水平上对手性农药的毒理机制进行全面深入的研究,对于评价农药对健康的风险及生产绿色高效的单一或复合的对映体农药具有指导意义。     

The effect of some Frescon analogs on the aquatic snail,Lymnaea stagnalis: I. Effect on the isolated central nervous system

Frescon (N-triphenylmethyl morpholine) is a strong neurotoxic agent when applied to the in vitro brain of Lymnaea stagnalis. Ten Frescon analogs were tested in order to determine their degree of neurotoxicity. Nine of the ten analogs were found to be neurotoxic to a greater or lesser degree. Triphenylmethanol (a hydrolysis product of Frescon), however, did not exhibit neurotoxicity. These results form part of an investigation to determine the plausibility of the snail central nervous system being a target for Frescon action.     

生物防治黄曲霉毒素污染研究进展

黄曲霉毒素（aflatoxin,AFT）是由黄曲霉（Aspergillus flavus）和寄生曲霉（A. parasiticus）产生的一类强致癌真菌毒素。生物防治是防治黄曲霉毒素污染的经济和有效方法之一,近年来,生物防治黄曲霉毒素污染的研究取得较大进展,并在生产上得到广泛应用。本文就近年来生物防治黄曲霉毒素方面的研究进行综述。     

甲草胺对非靶标生物的毒理学研究进展

甲草胺是一种选择性芽前除草剂,在20世纪末期被广泛应用于防治大豆、花生、水稻田等一年生禾本科及阔叶杂草。目前,甲草胺由于其致畸性及内分泌干扰活性已被多国禁用。文章综述了甲草胺进入环境后对非靶标生物的毒理学研究进展,主要包括急性毒性、慢性毒性和氧化应激效应等,旨在为甲草胺生态环境风险评估提供数据资料。     

Comparing ecological risks of pesticides: the utility of a Risk Quotient ranking approach across refinements of exposure

Environmental risk assessment of pesticides and other chemicals often uses the Risk Quotient (RQ) method to characterize risk quantitatively. An RQ is calculated by dividing an environmental exposure value by a toxicity end-point value. Tier 1 RQs, which are characterized by highly conservative toxicity and exposure assumptions, are used primarily for screening out negligible risks in regulatory decision making. It has been argued that the tier 1 RQ approach is valuable for making direct comparisons of quantitative risk between pesticides. However, an outstanding question is whether relative risks among pesticides would change if refinements of exposure are incorporated into the RQ calculations. This study tested that hypothesis. Aquatic ecological risk assessments were conducted for 12 herbicide and 12 insecticide active ingredients used on agricultural crops in the USA. The pesticides were chosen because surface-water monitoring data for them were available as part of the United States Geological Survey's National Water-Quality Assessment Program (NAWQA). Ecological receptors and effects evaluated were aquatic non-vascular plants (acute risk), aquatic vertebrates (acute risk) and aquatic invertebrates (acute risk) for the herbicides and aquatic vertebrates (acute and chronic risk) and aquatic invertebrates (acute and chronic risk) for the insecticides. The data indicate that there were significant statistical correlations between numerical rankings of tier 1 RQs and RQs using refined environmental exposures. The results support the hypothesis that numerical ranking of RQs for the purpose of comparing potential ecological risks is a valid approach because the rankings are significantly correlated regardless of the degree of exposure refinement.