四种除草剂对泥鳅红细胞遗传毒性的研究

采用红细胞微核和核异常测试法,研究了除草剂精禾草克、氟乐灵、扫茀特,2-甲-4氯钠水剂对泥鳅红细胞核的遗传毒性.结果表明,4种除草剂单独作用时均不同程度地引起微核细胞率和核异常细胞率等遗传指标的上升(P<0.05或P<0.01). 低浓度的除草剂对泥鳅红细胞的联合诱变作用比高浓度的除草剂明显.除草剂浓度与微核率或核异常率无显著相关,不表现剂量-效应关系.扫茀特的诱变效应大于其它3种除草剂.4种除草剂联合作用时具拮抗性. 图1 表5 参20     

三种除草剂对VA菌根真菌的侵染和植物生长的影响

用不灭菌的壤质黄潮土,在盆栽条件下研究了三种除草剂对VA菌根侵染和植物生长的影响。结果表明,三种除草剂的影响程度依次为绿麦隆>二甲四氯>氟乐灵;对菌根侵染的影响只出现在植物生长早期。接种VA菌根后,菌根侵染率、植物生长量、氮磷吸收量都显著大于不接种的对照植物。     

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。     

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.     

Concurrent Exposure Assessments of Atrazine and Metolachlor in the Mainstem, Major Tributaries and Small Streams of the Chesapeake Bay Watershed: Indicators of Ecological Risk

The goals of this study were to: (1) measure atrazine and metolachlor concentrations during both high and low use periods in the Chesapeake Bay's mainstem/major tributaries, smaller tributaries and representative small agricultural streams during 1995 and 1996; (2) compare these exposure data with toxicity benchmarks for each herbicide to predict ecological risk and (3) use in-stream fish community data collected in the streams to provide supportive data for ecological risk characterization. Spatially, atrazine (<0.10–98 g/L) and metolachlor (<0.10–68 g/L) concentrations were highest in the streams, followed by the small tributaries (<0.10–11 g/L atrazine; <0.10–8.6 g/L metolachlor) with the lowest concentration in the mainstem Bay/larger tributaries (<0.10–0.22 g/L atrazine; <0.10–0.24 g/L metolachlor). Temporally, concentrations of both herbicides were greatest in all three types of habitats in the late spring and early summer. Concentrations of atrazine and metolachlor were very low or non-detectable in all habitats sampled from early August to mid-April. Toxicity benchmarks of 20 g/L for atrazine based on an ecological No Observed Effect Concentration (NOEC) for microcosm/mesocosm studies and an acute 10th percentile of 53 g/L for metolachlor (protection of ninety % of the species) based on laboratory toxicity data were selected to assess annual and seasonal ecological risk. Both of these toxicity benchmarks were conservative estimates of ecological risk designed to protect the trophic group (plants) most sensitive to these herbicides. Based on a comparison of these toxicity benchmarks with two years of exposure data, the ecological risk from both atrazine and metolachlor exposure in the mainstem Chesapeake Bay/large tributaries, small tributaries and representative agriculturally dominated streams was generally judged to be low. During one 72-h stream rain event in 1995, the atrazine toxicity benchmark (20 g/L) was exceeded during part of the event. However, long-term permanent ecological effects are not expected based on the documented recovery potential of the most sensitive trophic group (plant communities) to the concentrations of atrazine reported and the transient nature of the atrazine pulses. Fish communities at the stream sites receiving the highest concentrations of both herbicides were judged to be healthy based on an Index of Biotic Integrity (IBI) developed for Maryland's coastal plain.     

Systematic review and meta-analysis of glyphosate exposure and risk of lymphohematopoietic cancers

This systematic review and meta-analysis rigorously examines the relationship between glyphosate exposure and risk of lymphohematopoietic cancer (LHC) including NHL, Hodgkin lymphoma (HL), multiple myeloma (MM), and leukemia. Meta-relative risks (meta-RRs) were positive and marginally statistically significant for the association between any versus no use of glyphosate and risk of NHL (meta-RR = 1.3, 95% confidence interval (CI) = 1.0–1.6, based on six studies) and MM (meta-RR = 1.4, 95% CI = 1.0–1.9; four studies). Associations were statistically null for HL (meta-RR = 1.1, 95% CI = 0.7–1.6; two studies), leukemia (meta-RR = 1.0, 95% CI = 0.6–1.5; three studies), and NHL subtypes except B-cell lymphoma (two studies each). Bias and confounding may account for observed associations. Meta-analysis is constrained by few studies and a crude exposure metric, while the overall body of literature is methodologically limited and findings are not strong or consistent. Thus, a causal relationship has not been established between glyphosate exposure and risk of any type of LHC.     

饮用水中苯基脲除草剂的分子印迹固相萃取方法研究

以N-（4-异丙基苯基）-N-亚丁基脲分子印迹聚合物为吸附剂,建立了饮用水中苯基脲除草剂的分子印迹固相萃取方法。上样后固相萃取柱依次用2．5mL0．1mol／L盐酸和2．5mL去离子水淋洗,然后氮气吹干,再用1mL含8％乙腈的甲苯溶液淋洗,最后用2mL甲醇洗脱。将建立的方法用于自来水中异丙隆、非草隆、甲氧隆、绿麦隆、枯莠隆、灭草隆、伏草隆、草不隆等8种苯脲类除草剂的测定,除伏草隆和草不隆的回收率较低外,其余6种除草剂的回收率均〉60％。