微板吸光法测定9种农药对斜生栅藻的抑制毒性

以斜生栅藻(Scenedesmus obliquus)为指示生物,96微孔板为暴露反应载体,SpectraMax M5酶标仪为吸光度测试设备,建立了测定毒物对藻生长抑制毒性的微板吸光法.论文系统研究了微板吸光法中斜生栅藻的可见吸收光谱和生长曲线以及pH和暴露时间对藻生长的影响,同时应用该方法成功测定了环嗪酮、阿特拉津、西草净、扑灭通、苯嗪草酮、敌草快、草甘膦7种除草剂和磷胺、甲胺磷2种杀虫剂对斜生栅藻的剂量-效应曲线(DRC).通过对剂量-效应数据进行非线性最小二乘模拟,获得了这些农药的半数效应浓度EC50及置信区间.对比标准锥形瓶栅藻毒性试验,微板吸光法具有测试简便快速,所需样品体积少,便于多次平行毒性测试等优点.     

Lethal and sublethal effects of four essential oils on the egg parasitoids Trissolcus basalis

The essential oils from leaves of Schinus molle var. areira, Aloysia citriodora, Origanum vulgare and Thymus vulgaris have showed potential as phytoinsecticides against the green stink bug, Nezara viridula. In this work were evaluated their toxicological and behavioral effects on the parasitoid Trissolcus basalis, a biological control agent of this pest insect. Essential oils were obtained via hydrodestillation from fresh leaves. Insecticide activity in T. basalis females was evaluated in direct contact and fumigation bioassays. Behavioral effects were evaluated in olfactometer bioassays. To evaluate the residual toxicity, females of the parasitoids were exposed to oil residues; in these insects, the sublethal effects were evaluated (potential parasitism and survivorship of immature stages). The essential oils from O. vulgare and T. vulgaris proved to be highly selective when used as fumigant and did not change parasitoid behavior. After one week, the residues of these oils were harmless and did not show sublethal effects against T. basalis. According with these results, essential oils have potential applications for the integrated management of N. viridula.     

Effects of two organophosphorus insecticides on some biochemical constituents in the nervous system and liver of rabbits

Abstract

Male Baladi rabbits were acutely and sub‐chronically intoxicated with cyanofenphos and profenophos. The levels of cholesterol, triglycerides, B‐lipoproteins and total proteins were determined in the serum, brain, spinal cord and sciatic nerve of rabbits. Moreover, the activities of alkaline phosphatase, acid phosphatase and glutamic‐pyruvic transaminase were determined in the liver of the animals. The whole Studie revealed that the biochemical constituents were highly affected by the tested insecticides. Also, the liver function suffered from adverse effects of the tested insecticides.     

Anthropogenic and naturally-produced organobrominated compounds in bluefin tuna from the Mediterranean Sea

In the present study, bioaccumulation potential of two pyrethroid insecticides, bifenthrin and permethrin, was measured using a Lumbriculus variegatus sediment bioaccumulation test. Two sediments differing in their physical characteristics and two different aging periods were tested. Desorption rates measured by Tenax extraction suggested that pyrethroids were bioavailable to L. variegatus, however bioavailability varied among chemicals, sediments and aging time, and was greater for permethrin than bifenthrin. The relatively low biota-sediment accumulation factor (BSAF) values resulted from the extensive biotransformation of pyrethroids by L. variegatus. Biotransformation capacity of L. variegatus to permethrin was further studied with a water-only exposure, and the percentage parent compound dropped to 36.0% after 14 d. These results indicated sediment-associated pyrethroids were bioavailable to L. variegatus, however bioaccumulation was limited because L. variegatus was capable of biotransforming the pyrethroids.     

我国微生物农药的应用现状

对微生物农药的概念、种类及其作用机理进行了综述，其中重点介绍了微生物农药的分类，同时对我国目前使用的几类微生物农药的研究应用状况进行了阐述，并提出微生物农药现存的问题及其解决方案，指出微生物农药的发展前景是乐观的。     

Organophosphorus insecticide residues in farm ditches of the Lower Fraser Valley of British Columbia

Abstract

Farm ditches flowing into three important rivers in the Lower Fraser Valley of British Columbia, Canada, were sampled periodically at seven locations from July to December in 1991, to determine the occurrence and levels of seven organophosphorus (OP) insecticides. Based oh sales records for the year, the uses of OP insecticides in this area were as follows: malathion > diazinon > parathion > dimethoate > azinphos‐methyl > fensulfothion, but no sales of chlorfenvinphos. Residues of parathion, diazinon, fensulfothion, dimethoate and chlorfenvinphos were detected at levels ranging from 1 ‐ 7,785 >μg/kg in cropped soils collected from areas adjacent to the sites for sampling ditch water and sediments. Malathion and azinphos‐methyl were not detected in any of the substrates studied, demonstrating their rapid degradation in the environment. Diazinon and dimethoate were consistently found in ditch water at seven locations, with an average concentration of 0.07 μg/L and 0.27 μg/L, respectively. Fensulfothion and parathion, with an average concentration of 0.08 μg/L and 0.17 μg/L, respectively, were sporadically found in ditch water at two locations. In ditch sediments, diazinon was detected at three locations and fensulfothion at two. The average concentrations of these two insecticides were 16 μg/kg and 9 jug/kg, respectively. The potential impact on aquatic organisms of these OP insecticides in ditches is discussed.     

Pesticides residues in vegetables in and around Delhi

This article presents the development of a multiresidue method forthe estimation of 30 insecticides, 15 organochlorineinsecticides and 6 organophosphorus insecticides, 9 syntheticpyrethriods and 2 herbicides and their quantificationin vegetables. The monitoring study indicates that though allthe vegetable samples were contaminated with pesticides, only31% of the samples contained pesticides above the prescribedtolerance limit.     

Insecticide Contamination of Jamaican Environment. IV. Transport of the Residues Coffee Plantations in the Blue Mountains to Coastal Waters in Eastern Jamaica

A survey of 120 coffee farmers in the Portland watershed revealed that they lacked training in pesticide application, and had no concept of the transport of residues in the environment and their impact on non-target organisms.Residues of organochlorine (OC) and organophosphorous compounds (OP) were monitored monthly for over a year in plantation soil, and water, sediment and fauna of three rivers and coastal waters of Portland watershed by gas chromatography. OP residues were not detected in any sample while OC residues were below detection levels in Rio Grande. The mean concentration ± standard error of residues detected in water (g L^_1), sediment (ng g^_1) and fauna (ng g^_1 in wet weight) were: -endosulfan 2.7 ± 1.29, 3.8 ± 0.15 and 15.9 ± 1.61, respectively, in Spanish River, 1.56 ± 0.43, 24.3 ± 16.44 and 9.0 ± 1.86, respectively, in Swift River; 0.40 ± 0.02, 1.77 ± 0.68 ± 12.63, respectively, in sea coast; -endosulfan, 1.2 ± 0.48, 0 and 8.1 ± 1.99, respectively, in Spanish River, 1.9 ± 0.49, 0.75 ± 0.32 and 11. ± 4.32, respectively, in Swift River; 0, 5.1 ± 0.30 and 30.9 ± 15.96, respectively, in sea coast; endosulfan sulphate, 0.12 ± 0.12, 4.8 ± 1.62 and 10.0 ± 2.02, respectively, in Spanish River, 3.6 ± 0.95, 3.1 ± 0.56 and 7.9 ± 1.29, respectively, in Swift River and 0, 3.9 ± 2.17 and 24.0 ± 14.67, respectively, in sea coast.Dieldrin residues were detected only once in water (0.2 ± 0.03) and sediment (0.02 ± 0.003) of Spanish River, water (0.76 ± 0.09) of Swift River and sediment (0.1 ± 0.005) of sea coast; pp DDE was found twice in water (3.1 ± 1.53) and sediment (0.1 ± 0.007) of Swift River and water (0.8 ± 0.22) and sediment (6.14 ± 0.41) of sea coast. Arochlor was detected only twice (0.011 and 0.153) in water of Spanish River.     

基因工程技术在降解农药中的应用

综述基因工程技术:基因重组、原生质体融合、利用外源基因、降解酶和固相反应器等在降解农药中的研究进展,提出几种高效基因工程降解菌的构建策略和构建手段。     

Identification of urinary metabolites in rats administered the fluorine-containing pyrethroids metofluthrin,profluthrin, and transfluthrin

The major metabolites in urine of rats administered the fluorine-containing pyrethroids transfluthrin, profluthrin, and metofluthrin, which are used widely recently as mosquito repellents or mothproof repellents, were identified to establish biological indexes for evaluating the absorption amounts of these pyrethroids in the general population. A single dose of 300?mg?kg^?1 body weight of each pyrethroid was separately administered intraperitoneally to male Sprague-Dawley rats and urine samples were collected until 24 hours after the administration. The metabolites identified by gas chromatography-mass spectrometry were as follows: 2,3,5,6-tetrafluorobenzyl alcohol, 2,3,5,6-tetrafluorobenzoic acid, and 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylic acid (DCCA) for transfluthrin; 4-methyl-2,3,5,6-tetrafluorobenzyl alcohol, 4-methyl-2,3,5,6-tetrafluorobenzoic acid, 4-hydroxymethyl-2,3,5,6-tetrafluorobenzyl alcohol (HOCH₂–FB–Al), and 2,2-dimethyl-3-(1-propenyl)-cyclopropanecarboxylic acid (MCA) for profluthrin; 4-methoxymethyl-2,3,5,6-tetrafluorobenzyl alcohol, HOCH₂–FB–Al and MCA for metofluthrin. In addition, several compounds estimated to be metabolites were detected as follows: hydroxylated DCCA and its lactone for transfluthrin; 4-hydroxymethyl-2,3,5,6-tetrafluorobenzoic acid (HOCH₂–FB–Ac), hydroxylated MCA and its lactone for profluthrin; 4-methoxymethyl-2,3,5,6-tetrafluorobenzoic acid, HOCH₂–FB–Ac, hydroxylated MCA, and its lactone for metofluthrin. The pyrethroids administered underwent metabolic reactions such as ester hydrolysis and oxidation, and most of the metabolites were excreted as their conjugates into urine. These findings should be useful as basic data for evaluating the health effects of exposure to pyrethroids for the general population.