Effects of Contaminants on Toxicity of the Lampricides TFM and Bayer 73 to Three Species of Fish

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.     

中国水稻害虫发生与防治研究进展

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     

Occurrence of Lawn Care and Agricultural Pesticides in the Don River and Humber River Watersheds (1998–2002)

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.     

我国给水内分泌干扰物问题

文章介绍了内分泌干扰物的危害，内分泌干扰物的分类，我国给水中内分泌干扰物的污染现状以及给水工作中有关内分泌干扰物的问题。     

传统法制备嗪草酮印迹聚合物

农药嗪草酮应用广泛,它的残留问题引起了人们的普遍关注,发展快速准确的检测方法势在必行。而分子印迹技术因其独特的优点使它成为痕量残留快速检测的一种较好的方法。采用传统法制备嗪草酮印迹聚合物,以甲基丙烯酸(MAA)为功能单体,N,N-亚甲基双丙烯酰胺为交联剂,甲苯为溶剂,在50℃时聚合得到选择性、吸附性最佳的印迹聚合物。     

国外农药开发现状与中间体需求（2）

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...     

几种农药对芒果树白蛾蜡蝉的药效试验

比较测定了10%吡虫啉可湿性粉剂、20%好年冬乳油和48%乐斯本乳油等3种药剂在常规用量下对芒果上发生的白蛾蜡蝉的防治效果。结果表明,乐斯本1000倍液和好年冬1500倍液对白蛾蜡蝉具有较好的速效性,药后1 d的防效分别为80.44%和73.98%;吡虫啉2000倍液对白蛾蜡蝉具有较好的持效性,药后7 d的防效仍然达79.61%;认为使用吡虫啉防治白蛾蜡蝉的适宜浓度为1500~2000倍。     

超临界流体萃取脱除人参中痕量有机氯农药

The feasibility of removal of the organochlorine pesticides residues of hexachlorocyclohexane(BHC) from radix ginseng with supercritical CO2 was explored. Some factors, such as extraction pressure, extraction temperature, and kinds of co-solvents were investigated. The experimental results indicate that it is possible to reduce BHC residues in radix ginseng to the level of 0.1×10-6 with supercritical CO2 in the presence of suitable amount of co-solvent, such as water.     

国内甲胺磷生产技术进展

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。     

2,6-二氯-4-三氟甲基苯胺的研究进展

2，6－二氯－4－三氟甲基苯胺可以作为制备高效、低毒、低残留农药和新型高效除草剂的中间体，其重要性日益为有机化学家和农药生产企业所重视。本文介绍合成该化合物的各种方法对各自的优缺点进行了比较，并对由其合成的各种农药、除草剂的特性和用途进行了综述。