农业地区人群膀胱癌死亡率与环境中农药暴露的相关性

分析农业地区人群膀胱癌死亡率与环境中农药暴露是否存在相关关系。方法收集沈阳市六个郊区县的农药资料和膀胱癌死亡资料，用SPSS(10.0)统计软件进行spearsman等级相关及线性回归分析。结果农业用途和杀菌剂及其它种类的农药使用密度与膀胱癌死亡率显著正相关。按性别分析，男性膀胱癌死亡率与农业用途、杀菌剂及其它种类的农药使用密度显著正相关；而女性膀胱癌死亡率只与畜牧业用途的农药使用密度显著相关。线性回归分析显示男性与农业用途和其它种类、女性与畜牧业用途的农药使用密度存在线性依存关系。结论农业地区人群膀胱癌死亡率与环境中农药暴露存在相关关系。     

The Complex Role of Lactic Acid Bacteria in Food Detoxification

Toxic ingredients in food can lead to serious food-related diseases. Such compounds are bacterial toxins (Shiga-toxin, listeriolysin, Botulinum toxin), mycotoxins (aflatoxin, ochratoxin, zearalenone, fumonisin), pesticides of different classes (organochlorine, organophosphate, synthetic pyrethroids), heavy metals, and natural antinutrients such as phytates, oxalates, and cyanide-generating glycosides. The generally regarded safe (GRAS) status and long history of lactic acid bacteria (LAB) as essential ingredients of fermented foods and probiotics make them a major biological tool against a great variety of food-related toxins. This state-of-the-art review aims to summarize and discuss the data revealing the involvement of LAB in the detoxification of foods from hazardous agents of microbial and chemical nature. It is focused on the specific properties that allow LAB to counteract toxins and destroy them, as well as on the mechanisms of microbial antagonism toward toxigenic producers. Toxins of microbial origin are either adsorbed or degraded, toxic chemicals are hydrolyzed and then used as a carbon source, while heavy metals are bound and accumulated. Based on these comprehensive data, the prospects for developing new combinations of probiotic starters for food detoxification are considered.     

Methamidophos,dichlorvos, O‐methoate and diazinon pesticides used in Turkey make a covalent bond with butyrylcholinesterase detected by mass spectrometry

Organophosphorus pesticides used most commonly in Turkey include methamidophos, dichlorvos, O‐methoate and diazinon. These toxic chemicals or their metabolites make a covalent bond with the active site serine of butyrylcholinesterase. Our goal was to identify the adducts that result from the reaction of human butyrylcholinesterase with these pesticides. Highly purified human butyrylcholinesterase was treated with a 20‐fold molar excess of pesticide. The protein was denatured by boiling and digested with trypsin. MS and MSMS spectra of HPLC‐purified peptides were acquired on a MALDI‐TOF‐TOF 4800 mass spectrometer. It was found that methamidophos added a mass of +93, consistent with addition of methoxy aminophosphate. A minor amount of adduct with an added mass of +109 was also found. Dichlorvos and O‐methoate both made dimethoxyphosphate (+108) and monomethoxyphosphate adducts (+94). Diazinon gave a novel adduct with an added mass of +152 consistent with diethoxythiophosphate. Inhibition of enzyme activity in the presence of diazinon developed slowly (15 h), concomitant with isomerization of diazinon via a thiono‐thiolo rearrangement. The isomer of diazinon yielded diethoxyphosphate and monoethoxyphosphate adducts with added masses of +136 and +108. MSMS spectra confirmed that each of the pesticides studied made a covalent bond with serine 198 of butyrylcholinesterase. These results can be used to identify the class of pesticides to which a patient was exposed.     

Organophosphorus pesticide exposure decreases sperm quality: association between sperm parameters and urinary pesticide levels

Several studies have suggested that human semen quality has declined over the past decades and some of them have associated it with occupational exposure to pesticides. However, most of these studies have not been associated with a reliable exposure level and have been designed mostly as cross-sectional studies. The present work evaluates, in a longitudinal follow-up study, the effect of organophosphate pesticides (OP) at three occupational exposure levels on semen quality. In addition, the study examined the association between OP urinary levels and sperm parameters in exposed and unexposed workers. A total of 139 semen samples from 52 volunteers were assessed. Urinary OP levels were measured by gas-liquid chromatography.The results revealed that the poorest semen quality was found among the subjects with the highest OP exposure and the highest urinary OP levels. Seasonal variations in sperm concentration and sperm count were registered.The results showed a significant decrease in total sperm count among subjects with the highest exposure to OP. Further studies assessing the effects of OP on male reproductive health should be controlled by the variability in human sperm parameters, sperm seasonality, spermatogenesis time and the changing OP exposure level in men highly exposed to OP.     

有机氯农药残留量的气相色谱检测方法研究

建立了西洋参中有机氯农药残留量的气相色谱的分析方法。样品以丙酮提取，在NaCl存在下，以二氯甲烷进行液液分配，提取液以浓H2SO4净化，采用SE－54弹性石英毛细管柱，GCECD检测有机氯（六六六，DDT异构体及七氯，艾氏剂）农药的残留量，最低检测浓度为3．2×10－2ng／g～1．4ng／g，添加回收率在80％～133．18％，并对北京及东北产西洋参药材进行了实际残留量测定。     

分散固相萃取技术结合超高效液相色谱-高分辨质谱法测定蜂蜜中三嗪类农药残留

目的:采用分散固相萃取技术(DSPE),建立蜂蜜中21种三嗪类农药残留的同时测定分析方法。方法:用15%氯化钠水溶液溶解蜂蜜后,以1%甲酸乙腈进行盐析提取,提取液经DSPE净化后,采用超高效液相色谱-高分辨质谱(UHPLCHRMS)进行外标法定量检测。结果:21种三嗪类农药在各自浓度范围内具有较好的线性相关系数(r0.999)。目标化合物在低、中、高3个浓度下的平均回收率为73.9%~110.4%(RSD 1.5%~9.6%),定量限(LOQ)为1~10μg·kg-1。结论:该方法灵敏度高、准确性好,适合蜂蜜样品中21种三嗪类农药的快速准确定量分析。     

血清中16种有机磷农药GC/MS/MS检测方法的研究

目的应用GC/MS/MS建立测定血清中敌敌畏、氧化乐果等16种有机磷农药的分析方法。方法首先做GC/MS全扫描分析,确定16种化合物的母离子,然后比较不同碰撞诱导裂解(CID)电压时二级质谱中特征离子的峰面积大小以及信噪比,对CID电压进行优化,从而确定各化合物的色谱质谱条件。样品用Oasis HLB小柱进行固相萃取后,用乙酸乙酯洗脱,浓缩后再用乙酸乙酯定容后上机测定。结果在0～1000ng/ml范围内,16种化合物的线性相关系数均大于0.995,加标回收率在75%～129%之间,RSD<10%;日内和日间相对标准偏差小于15%(n=6)。除敌敌畏的检测限为55ng/ml外,其余待测物均检出限均小于2ng/ml。结论该方法灵敏度高、准确性好,适合于血清中有机磷农药的分析测定。     

A Current Review of Cypermethrin-Induced Neurotoxicity and Nigrostriatal Dopaminergic Neurodegeneration

Cypermethrin, a class II pyrethroid pesticide, is used to control insects in the household and agricultural fields. Despite beneficial roles, its uncontrolled and repetitive applications lead to unintended effects in non-target organisms. Cypermethrin crosses the blood-brain barrier and induces neurotoxicity and motor deficits. Cypermethrin prolongs the opening of sodium channel, a major site of its action, leading to hyper-excitation of the central nervous system. In addition to sodium channel, cypermethrin modulates chloride, voltage-gated calcium and potassium channels, alters the activity of glutamate and acetylcholine receptors and adenosine triphosphatases and induces DNA damage and oxidative stress in the neuronal cells. Cypermethrin also modulates the level of neurotransmitters, including gamma-aminobutyric acid and dopamine. It is one of the most commonly used pesticides in neurotoxicology research not only because of its variable responses depending upon the doses, time and routes of exposure and strain, age, gender and species of animals used across multiple studies but also owing to its ability to induce the nigrostriatal dopaminergic neurodegeneration. This article describes the effect of acute, chronic, developmental and adulthood exposures to cypermethrin in experimental animals. The article sheds light on cypermethrin-induced changes in the central nervous system, including its contribution in the onset of specific features, which are associated with the nigrostriatal dopaminergic neurodegeneration. Resemblances and dissimilarities of cypermethrin-induced nigrostriatal dopaminergic neurodegeneration with sporadic and chemicals-induced disease models along with its advantages and pitfalls are also discussed.     

Comparison of Farmers in the Agricultural Health Study to the 1992 and 1997 Censuses of Agriculture

Abstract

Context: The Agricultural Health Study (AHS) is a large, prospective cohort study in the states of Iowa and North Carolina that has been developed to better understand how pesticides and other agricultural exposures relate to the occurrence of cancer and other diseases.

Purpose: This report compares the characteristics of AHS farmers to the Census of Agriculture to evaluate the generalizability of AHS findings.

Methods: We restricted the AHS to private pesticide applicators who enrolled in Iowa (n = 31,065) and in North Carolina (n = 17,239) between 1993 and 1997, and who identified themselves as living or working on a farm. We compared their self-reported data with data from the 1992 and 1997 Censuses of Agriculture.

Findings: AHS farmers in Iowa are younger; live or work on larger farms; more frequently apply herbicides, insecticides, and fungicides; and are more likely to raise beef cattle and swine, and grow corn, soybeans, hay, and oats. AHS farmers in North Carolina are also younger, live or work on larger farms, more frequently reported growing crops commonly seen in the state, and are more frequent pesticide users. However, animals raised are similar to those in the North Carolina Census of Agriculture.

Conclusions: AHS farmers likely represent the higher end of pesticide usage in both states in part because AHS farmers have larger farms. Since the health effects of pesticides are best ascertained among pesticide users with the greatest exposure, the AHS cohort should prove to be a valuable resource for health effects research.     

Pesticide-related Illness and Injuries among Banana Workers in Costa Rica: A Comparison between 1993 and 1996

Abstract

An intervention program considerably decreased systemic poisonings on banana plantations in Costa Rica in the early 1990s. Nevertheless, pesticide safety continues to be controversial .To examine the determinants of acute pesticide related illness on banana plantations, the authors surveyed occupational injuries and illness among banana workers in the Atlantic Region of Costa. Rica that were reported during 1993 and 1996 to the National Insurance Institute. Incidence rates were calculated for categories of pesticides and types of medical problems, for all and subgroups of banana workers. Between 1993 and 1996, an overall 35% decrease in injuries was observed, attributable to a marked decline in topical injuries (3.3 vs 1.9 per 100 workers), whereas systemic poisonings remained the same (0.7 per 100 in both years). The decrease concerned selectively milder skin contlltioris, indicating underreporting of less severe health effects. In both years, paraquat was the pesticide most frequently associated with injuries, mostly skin and eye lesions. Workers at highest risk per unit time of exposure were nematocide applicators, herbicide applicators, and cleaners of packing plants. Despite control measures, further reduction of systemic illness had not been achieved. The decrease of topical injuries may be partly explained by improved work conditions, but possible underreporting hinders interpretation. Pesticide related illness on banana plantations is a persistent problem.