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1.
Waters in the Great Lakes basin contain more than 400 contaminant chemicals that potentially affect fishery resources, commerce, and human inhabitants. We determined in the laboratory the effects of selected contaminants on the toxicity of the widely used lampricides TFM (3-trifluoromethyl-4-nitrophenol) and Bayer 73 (2′,5-dichloro-4′-nitrosalicylanilide) to three species of fish—rainbow trout (Salmo gairdneri), white sucker (Catostomus commersoni), and fathead minnow (Pimephales promelas). The fish were exposed to paired mixtures of lampricides and selected contaminants in standardized, acute static toxicity tests to determine the resulting type of response—less than additive, additive, or greater than additive (synergistic). As expected, the toxicities of combinations of lampricides with organic pesticides, metal, industrial or municipal pollutants, and tannic acid were mostly additive. However, the toxicity of a combination of TFM, Delnav, and malathion was synergistic, and extremely small quantities of each chemical became lethal when mixed. The concentration that produced 50% mortality was 1.64 mg/L for TFM alone but only 0.041 mg/L for TFM with the pesticides. Toxicities of the pesticides in the combination also increased commensurately. The triple combination of chemicals produced extraordinary synergism and effectively demonstrated the hazards that may result if certain chemical combinations occur in the aquatic environment. However, synergism is not the only kind of toxic action that produces hazards to aquatic organisms. All three types of toxic action are of concern because toxic units produced by contaminant chemicals add to the toxic units of applied management chemicals. Since the toxicity of the majority of chemical combinations is simply additive, this cumulative toxic action contributes more total units to aquatic environments than the extreme actions of less than additive and synergism. The toxicity of the lampricide TFM, as well as other management chemicals, is reinforced by the presence of any contaminant that contributes additional units of toxicity. Therefore, all types of cumulative toxic action should be of concern to people and agencies involved with protecting the environment. 相似文献
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本文介绍了我国水稻害虫发生的种类,主要稻虫的种群消长,对水稻危害的损失,在各个不同年代,通过研究和防治,总结出对抗虫品种评价与利用的研究发展迅速,新农药的试验开发效果明显。70年代以来,按我国稻区生态条件和稻虫为害的特点,形成了江淮、太湖平原、川西平原、洞庭湖平原和珠江三角洲五大稻区的水稻病虫综合防治技术体系,主要技术路线是以农业防治为基础,抗性品种为主体,依靠经济防治指标,协调农药防治和利用天敌 相似文献
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Between 1998 and 2002, surface water samples were collected from several sites in the Don River and Humber River watersheds, both tributaries to Lake Ontario, and analyzed for a variety of pesticides, including those used for urban lawn care. Analyses included 152 pesticide active ingredients and eight metabolites. Samples were collected during base flow periods (i.e., dry events) and rainfall events (i.e., wet events). The objectives of the study were to determine which pesticides were detectable, whether there was a difference in the detection frequency between the two watersheds and between upstream and downstream in each river, and whether precipitation influenced the frequency of detection. Eleven pesticides and one metabolite were detected in surface waters of the Don and Humber rivers or their tributaries, with approximately 72% of samples containing at least one pesticide attributable to lawn care use. The pesticides and pesticide metabolite detected in this study included 2,4-D, atrazine, bromacil, carbofuran, chlorpyrifos, cypermethrin, diazinon, dicamba, MECOPROP, metolachlor, metribuzin, and an atrazine metabolite (des-ethyl atrazine). Four pesticides exceeded federal or provincial water quality guidelines/objectives. Diazinon exceeded the provincial water quality objective in 28% of the samples taken. For the three other pesticides (atrazine, carbofuran and chlorpyrifos) exceedance of a water quality criteria occurred in less than 1% of the samples. 相似文献
4.
为分析新型低毒有机磷杀虫剂“1%双硫磷颗粒”投放对河道水质的影响,设置不同药剂投放浓度和不同反应时间的室内试验,以TP、NH3-N及S2-为目标因子,分析该药剂投放后水体污染物浓度。结果表明:不同试验组水样中S2-质量浓度均小于0.02 mg/L,NH3-N质量浓度处于0.029~0.036 mg/L之间,均达到地表水Ⅰ类标准;不同浓度药剂投放1 h后,水体TP质量浓度已达到稳定状态,且在60 h内均保持稳定,药剂投加量与水体TP质量浓度呈显著正相关(R2=0.85);不同处理组的药剂在水体中的TP释放量无明显差异,均在1.06~1.30 mg/g之间。“1%双硫磷颗粒”推荐适宜投放量不会使河道水质恶化到劣Ⅴ类,但增加药剂投放量会增加水体TP污染及富营养化风险。 相似文献
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国外农药开发现状与中间体需求(2)刘长令(化工部沈阳化工研究院,沈阳110021)三、新近开发的农药及中间体需求近几年新出现的农药类型很多,本文仅对部分类型(文献较多或参与公司较多的)予以介绍。1.吡啶系列农药吡啶类杀菌剂有已知的啶斑肟及新近开发的I... 相似文献
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国内甲胺磷生产技术进展 总被引:9,自引:0,他引:9
甲胺磷是一种广谱性有机磷杀虫剂,它是我国生产吨位最大的农药品种。本文从合成工艺路线、生产技术现状、现存技术问题及工艺改进等方面介绍了我国甲胺磷生产的技术进展。建议应有效地控制产量增加,着重收率和含量的提高。 相似文献
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利用有机磷杀虫剂敌百虫属酯类化合物在碱性条件下易水解成醇类、酚类和磷酸的性质,将水解产物醇类、酚类与具氧化性的KMnO4有色液反应使溶液的颜色发生改变,根据试液颜色的改变程度与敌百虫量的关系制成标准比色卡,用色卡法快速检测水果蔬菜中有机磷农药残留量。研究表明,该方法对敌百虫的检测灵敏度为0.058mg/kg,单个样品全过程检测只需5min,具有检测时间短、成本低、简单方便、快捷等特点,适用一般家庭或农贸市场、超市快速检测水果、蔬菜中有机磷农药残留量。 相似文献