国外有机磷农药神经发育毒性研究

有机磷农药目前占我国农药使用量的80%以上,长期低水平暴露对婴幼儿神经系统发育的影响不容忽视。有机磷农药毒作用机制研究甚多,众多研究表明,乙酰胆碱酯酶除水解乙酰胆碱外,还可能作为一种可分泌到胞外调控细胞增殖与轴突生长的神经营养因子,在神经系统发育的关键时期影响神经细胞的生长、分化和脑的正常功能。本文就近年来国外有机磷农药神经发育毒性研究概况及进展作一综述。     

117 国外有机磷农药神经发育毒性研究

有机磷农药目前占我国农药使用量的80%以上,长期低水平暴露对婴幼儿神经系统发育的影响不容忽视.有机磷农药毒作用机制研究甚多,众多研究表明,乙酰胆碱酯酶除水解乙酰胆碱外,还可能作为一种可分泌到胞外调控细胞增殖与轴突生长的神经营养因子,在神经系统发育的关键时期影响神经细胞的生长、分化和脑的正常功能.本文就近年来国外有机磷农药神经发育毒性研究概况及进展作一综述.     

有机磷农药的联合毒性研究进展

有机磷农药应用广泛,其使用量占我国农药总量的80%以上.人群可通过多种途径(水、空气、膳食)同时或相继暴露于两种或多种有机磷农药.多种有机磷农药在体内共存,产生联合毒性,对人体健康造成严重危害.该文阐述了有机磷农药的联合暴露对人体健康可能产生的不良影响,包括神经毒性、生殖毒性、致癌作用,并分析了有机磷农药产生联合毒性的机制;根据国内外对有机磷农药联合暴露的研究现状,提出了我国在有机磷农药联合毒性方面应开展的研究工作.旨在推动我国食品中农药残留风险性评估体系的建立以及为食品中农药残留限量标准的制定提供理论支持,保障食品的安全.     

我国农药使用状况和农药对健康的影响研究

随着世界各国农业的飞速发展，农药在农业中扮演着越来越重要的角色。我国农药市场的农药种类繁多，农药的使用量逐年增加，喷洒农药的过程中农民缺乏安全防护意识，蔬菜水果及环境中农药残留问题严重，对人体健康构成了严重威胁。文章介绍了我国农业生产中使用的农药种类、数量及使用情况，分析了农药对人体健康的影响，探讨了农药在农产品和环境中残留的问题及相关研究进展，为开展相关研究提供参考依据。     

有机磷农药生物标志物的研究进展

生物标志物 (biomarker)常常被用来监测毒性物质的接触水平、毒性反应及预测可能的毒性作用 ,其应用越来越受到重视。本文主要介绍了有关有机磷农药的生物标志物。有机磷农药具有高效、低毒和低残留的优点而广泛用于农业生产。根据氧原子或硫原子的不同 ,可分成不同亚类。目前在有机磷农药接触的生物监测中 ,胆碱酯酶可用作效应生物标志物 ,尿中的代谢产物是接触生物标志物 ,对氧磷酶是易感性生物标志物。神经毒酯酶(NTE)常用来作为迟发性神经病的生物标志物 ,由于只有少数有机磷农药能引起此病 ,所以本文未作详细介绍。1　胆碱酯酶作为生…     

孕期低水平铅暴露与儿童发育行为学的关系

近年来的研究表明,即使血铅水平在10 μg/L以下,也会影响儿童的神经发育,故目前美国国家疾病预防控制中心不再认为10 μg/L为儿童血铅水平的安全阈值。由于胎儿神经系统易受外界因素的影响,因此孕期低水平铅暴露对儿童神经发育的损害逐步受到重视,本文就孕期低水平铅暴露与儿童发育行为学的关系进行综述。     

035 血、尿中有机磷农药及其代谢产物检测方法的研究进展

有机磷农药(OP)为有机磷酸酯类化合物,因具有低毒和低残留的优点而被广泛用作农业杀虫剂、杀菌剂、除草剂、植物生长调节剂等,目前OP占我国农药使用量的70%以上.长期低剂量接触可引起迟发性神经疾病,严重时可诱变和致癌.预防和处理OP引起的环境污染和食品污染等问题,首先需要及时、准确地检测有机磷,而评价人群OP的暴露剂量最有效的办法就是对人体体液中OP及其代谢产物进行直接监测.     

血、尿中有机磷农药及其代谢产物检测方法的研究进展

有机磷农药（OP）为有机磷酸酯类化合物，因具有低毒和低残留的优点而被广泛用作农业杀虫剂、杀菌剂、除草剂、植物生长调节剂等，目前OP占我国农药使用量的70％以上。长期低剂量接触可引起迟发性神经疾病，严重时可诱变和致癌。预防和处理OP引起的环境污染和食品污染等问题，首先需要及时、准确地检测有机磷，而评价人群OP的暴露剂量最有效的办法就是对人体体液中0P及其代谢产物进行直接监测。     

有机磷农药联合毒性研究进展

有机磷类农药是我国使用量较大的农药,近年来有机磷农药的联合毒性受到广泛关注。文章归纳了有机磷农药的联合毒性对人体健康的影响,包括遗传毒性、致癌作用、生殖毒性、神经毒性、免疫毒性等,并对其可能的作用机制进行综述;为建立和完善高效、科学的有机磷农药使用方法和有机磷农药联合暴露的风险性评价提供相应的毒理学依据。     

有机磷农药的雌性生殖毒性研究进展

有机磷农药广泛应用于农业生产和居住环境。由于发现有机磷农药暴露与胎儿神经管畸形、内脏畸形等出生缺陷有关,故其生殖毒性及其机制的研究成为近年来环境医学领域关注的热点。本文综述了有机磷农药对雌性生殖系统的毒性作用、对性周期和性行为的影响以及对生殖结局的毒性作用,并探讨其产生生殖毒性的可能机制。     

长期接触低剂量有机磷农药对人体健康影响的研究进展

有机磷农药（OPs）是我国使用量最大的一类农药之一，广泛使用于水果、蔬菜、烟草、棉花等作物。近年来，由OPs引起的急性中毒事件已逐步减少，而长期低剂量暴露OPs对人体健康的危害逐渐引起了人们的重视。越来越多的研究发现长期低剂量暴露OPs与人体肿瘤的发生，不良生殖结局，神经及神经行为功能的异常有密切关系。     

Impact of low-level exposure to organophosphates on human reproduction and survival

Despite their widespread and longstanding use for the public good, organophosphate (OP) pesticides have led to many adverse effects on human health. Environmental exposure to OPs and adverse reproductive outcomes in men and women working on or living near farms are increasingly reported worldwide. The aim of the current review is to determine whether exposure to OPs, at levels lower than that which results in clinical manifestations of acute OP poisoning, leads to an adverse impact on fertility, growth and development, and to highlight possible effects for further investigation. There is evidence of impaired fertility due to a reduction in semen quality and possibly lower testosterone levels in exposed males. There is also evidence of impairment of fetal growth and development brought about by prenatal exposure to OPs. Paraoxonase gene (PON1) activity in the fetus and during early childhood makes the fetus and child more vulnerable to OP poisoning, suggesting that OP exposure has a greater impact on fetal and infant growth and development than on adults when exposed to the same concentrations of pesticides. This review raises concerns that exposure to OP pesticides at levels currently regarded as safe adversely affect human reproductive function and survival.     

The Hazards of Organophosphates

ABSTRACT

The study examines aspects of the toxicological and occupational hygiene assessment of organophosphates (OPs) related to the use of sheep dips in the UK. Scientific and agricultural literature produced in the past revealed a range of potential hazards to humans from these veterinary pesticides but health and safety standards failed to address those hazards. The results of the research raise questions about the validity of past risk assessments of OPs in the UK; indicate significant under-reporting of adverse health effects in humans associated with exposure to OPs in sheep dipping; reveal shortcomings in the approval and monitoring of veterinary medicines from an occupational health and safety perspective.     

农药混剂联合毒性评价

用Ｈａｒｒｉｓ法研究了３类杀虫剂（有机磷,拟除虫菊酯和氨基甲酸酯）的二元混剂对大鼠的急性毒性联合作用,涉及的有机磷类农药有：甲基对硫磷,乐果,甲胺磷,辛硫磷,敌敌畏,丙溴磷,马拉硫磷,水胺硫磷;拟除虫菊酯类农药有：高效氯氰菊酯,氰戊菊酯,甲氰菊酯,溴氧菊酯：氨基甲酸酯类农药有：灭多威,异丙威,速灭威等。     

Qat chewing and pesticides: a study of adverse health effects in people of the mountainous areas of Yemen

Chewing qat leaves, Cathula Edulis, is now a very common behaviour among the people of the mountainous areas of Yemen. For about the past 20 years, in tandem with national development, qat chewing has been rapidly expanding, and the use of chemical pesticides in qat production has been increasing. In this study, the adverse effects on human health of qat chewing combined with pesticide use were investigated. Results of interviews and questionnaires showed that chewers of qat grown with few or no chemical pesticides and chewers of qat grown with chemical pesticides have considerably different subjective symptoms. Chewers of qat produced in fields where chemical pesticides are used regularly have more symptoms than chewers of qat produced in fields where chemical pesticides are rarely or never used. Chewers of qat produced with more chemical pesticides, in particular, experience acute adverse effects on the digestive system and chronic adverse effects such as body weakness and nasal problems. Farmers who chew homemade qat on which they spread chemical pesticides by themselves may have the highest health risks regarding the combination of qat and pesticides. It is concluded that chewing qat grown with chemical pesticides causes considerable adverse health effects in human beings.     

Dialkyl phosphate metabolites of organophosphorus in applicators of agricultural pesticides in Majes – Arequipa (Peru)

Background  

Organophosphorus (OPs) pesticides are the most commonly used pesticides in Peruvian agriculture. The population at risk for OPs exposure includes formulators, applicators and farmers. Majes Valley is the most important agricultural center of the Southern region of Peru. The present study was aimed to determine the knowledge about using OPs, safety practice and urinary dialkylphosphate metabolites on OP applicators in the Majes Valley, Peru.     

Pesticide exposure, safety issues, and risk assessment indicators

Pesticides are widely used in agricultural production to prevent or control pests, diseases, weeds, and other plant pathogens in an effort to reduce or eliminate yield losses and maintain high product quality. Although pesticides are developed through very strict regulation processes to function with reasonable certainty and minimal impact on human health and the environment, serious concerns have been raised about health risks resulting from occupational exposure and from residues in food and drinking water. Occupational exposure to pesticides often occurs in the case of agricultural workers in open fields and greenhouses, workers in the pesticide industry, and exterminators of house pests. Exposure of the general population to pesticides occurs primarily through eating food and drinking water contaminated with pesticide residues, whereas substantial exposure can also occur in or around the home. Regarding the adverse effects on the environment (water, soil and air contamination from leaching, runoff, and spray drift, as well as the detrimental effects on wildlife, fish, plants, and other non-target organisms), many of these effects depend on the toxicity of the pesticide, the measures taken during its application, the dosage applied, the adsorption on soil colloids, the weather conditions prevailing after application, and how long the pesticide persists in the environment. Therefore, the risk assessment of the impact of pesticides either on human health or on the environment is not an easy and particularly accurate process because of differences in the periods and levels of exposure, the types of pesticides used (regarding toxicity and persistence), and the environmental characteristics of the areas where pesticides are usually applied. Also, the number of the criteria used and the method of their implementation to assess the adverse effects of pesticides on human health could affect risk assessment and would possibly affect the characterization of the already approved pesticides and the approval of the new compounds in the near future. Thus, new tools or techniques with greater reliability than those already existing are needed to predict the potential hazards of pesticides and thus contribute to reduction of the adverse effects on human health and the environment. On the other hand, the implementation of alternative cropping systems that are less dependent on pesticides, the development of new pesticides with novel modes of action and improved safety profiles, and the improvement of the already used pesticide formulations towards safer formulations (e.g., microcapsule suspensions) could reduce the adverse effects of farming and particularly the toxic effects of pesticides. In addition, the use of appropriate and well-maintained spraying equipment along with taking all precautions that are required in all stages of pesticide handling could minimize human exposure to pesticides and their potential adverse effects on the environment.     

Organophosphate Pesticide Exposure in School-Aged Children Living in Rice and Aquacultural Farming Regions of Thailand

Organophosphate pesticides (OPs) are widely used in agricultural sectors in Thailand. Previous studies have documented that children residing in agricultural areas have higher exposure to OPs than children living in other residential areas. The objective of this study was to quantify urinary biomarkers of OP exposure and determine the environmental conditions and activities that predict their levels among children living in Central Thailand farming regions. In October 2011, 53 6–8-year-old participants were recruited from Pathum Thani Province, Thailand. Twenty-four lived in rice farming communities at Khlong Luang District where OPs are the pesticides used frequently. Twenty-nine participants, living in aquacultural farming communities at Lum Luk Ka District where OPs are not used, were recruited to serve as controls for pathways of exposure (e.g., residential, dietary) other than occupational/paraoccupational exposures encountered in rice farming. Household environments and participants’ activities were assessed using a parental structured interview. Urine samples (first morning voids) were collected from participants for OP urinary metabolite (i.e., dialkylphosphates [DAPs] and 3,5,6-trichloro-2-pyridinol [TCPy]) measurements. The levels of most urinary OP metabolites were significantly higher in participants who lived in a rice farming community than those who lived in an aquacultural farming community (P < .05). The results from linear regression analysis revealed that the frequency of OP application on rice farms (∑DAP: P = .001; TCPy: P = .001) and living in a rice farming community (∑DAP: P = .009; TCPy: P < .001) were significant predictors of urinary DAP metabolite levels in participants. Increasing TCPy levels were significantly related to proximity to rice farm (P = .03), being with parent while working on a farm (P = .02), playing on a farm (P = .03), and the presence of observable dirt accumulated on the child’s body (P = .02). In conclusion, OP metabolite levels among children who live in rice farming communities were strongly influenced by farming activity, household environments, and child behaviors, suggesting that these are the primary pathways in which children living in these agricultural communities in Thailand were exposed to OPs.     

Airborne concentrations of organophosphorus pesticides in Korean pesticide manufacturing/formulation workplaces

Pesticide manufacturing/formulation workers rather than farmers or applicators or people living with them are primarily exposed to organophosphorus pesticides (OPs). However, airborne concentrations in the workplace have rarely been determined. A total of 121 air samples (personal or area sampling) were collected at 4 factories where chlorpyrifos, EPN, parathion, and phorate, were manufactured/formulated from March through July, 2007-2008. Samples were collected by the National Institute for Occupational Safety and Health (NIOSH) method and were analyzed by GC-MS. The geometric mean (GM) level of airborne chlorpyrifos was 0.17 mg/m(3), 85% Korean Occupational Exposure Limit (KOEL) of 0.2 mg/m(3), and at 95% confidence, airborne concentrations exceeded the KOEL 58.8% of the time or less, indicating that this concentration level was unacceptable according to exposure assessment using a LogNorm2(?). However, compared with levels of TLV and/or PEL and/or WEL, the GM concentration levels of other OPs were remarkably low (range, 0.1-15.0%) and that these levels of concentrations to the other OPs were acceptable. The levels of airborne concentrations of OPs depended on isolation of the process; in other words, the levels depended on the extent to which the process was automated. The reason that the airborne concentration levels, except for those of chlorpyrifos, were very much lower than expected may be attributable to the fact that there was not exposed to 100% toxic active ingredients in pesticide formulation workplaces because of the use of supplemental agents or additives to produce complete pesticides. This study is limited since there were seldom or neither any data of previous studies to be compared with the study results nor dermal exposure data. The results were used to revise KOELs for OPs in 2010.     

Temporal trends of legacy and emerging persistent organic pollutants in inuit preschoolers from Northern Quebec (Canada)

ABSTRACT

In this study, we report the temporal trends of persistent organic pollutants (POPs) in 181 preschool Inuit children from Nunavik and the influence of confounding factors on blood contaminant levels. From 2006 to 2010, no significant trends were detected in Σpolychlorinated biphenyls (ΣPCBs), Σorganochlorine pesticides (ΣOPs), Σtoxaphene, and Σper- and polyfluoroalkyl substances (ΣPFASs). On the contrary, significant downward trends ranging from 9.3% to 14.3% per year were found for polybrominated diphenyl ethers (PBDEs). Breastfeeding was significantly associated with increased levels of POPs. Age was positively and significantly related to ΣPCBs, ΣOPs and Σtoxaphene. Compared with girls, boys had significantly higher concentrations of ΣPBDEs, but lower concentrations of ΣPFASs. Weight-for-height or body mass index z-scores were negatively and significantly related to ΣPCBs and ΣOPs. Passive smoking was positively and significantly associated with ΣOPs and Σtoxaphene. In conclusion, continued efforts to reduce contaminant exposure are needed to protect children’s health and development.