急性有机磷农药中毒时血清胆碱酯酶活性动态监测的临床意义

目的：探讨急性有机磷农药中毒（AOPP）患者血清胆碱酯酶（ChE）变化特点及其临床意义。方法：将88例AOPP患者根据中毒的程度分为轻度中毒、中度中毒和重度中毒组,采用硫代丁酰胆碱法检测患者血清ChE活性的动态变化,并结合患者临床症状改变进行分析和比较。实验中以31例健康体检者作为正常对照。结果：与正常对照组比较,AOPP患者血清ChE活性均明显降低（P〈0.01）,其下降幅度与临床中毒程度呈平行关系。结论：检测AOPP患者血清ChE活性对明确诊断、判断中毒程度及用药剂量等均有重要参考价值。     

对氧磷酶的基因多态性对有机磷作业工人血清对氧磷酶活力的影响

目的探讨对氧磷酶(PON1)的基因多态性对接触有机磷的作业工人血清对氧磷酶(sPON)活力的影响。方法采用标准曲线法测定作业工人和对照者sPON活力,PCR-限制性片段长度多态性分析PON1基因192位点的基因型。结果合并敌敌畏和对硫磷暴露组后,不同基因型sPON活力均值为195.0(谷氨酸纯合子,Gln/Gln)、304.6(谷氨酸/精氨酸杂合子,Gln/Arg)和368.4(精氨酸纯合子,Arg/Arg),呈Gln/Gln→Gln/Arg→Arg/Arg递增的趋势,并且差异有统计学意义(P=0.03)。结论PON1基因192位点的多态性影响sPON的活力,可能调节个体对甲基对硫磷的毒性的易感性。     

产妇体内有机氯农药残留对血中4种生殖激素水平的影响

[目的]探讨有机氯农药污染区产妇静脉血中有机氯农药目前的残留水平及其对血中生殖激素的影响。[方法]抽取2004年1月1日至4月30日在湖北省天门市妇幼保健院住院分娩的产妇71名，分别采集产妇静脉血和脐带血样各1份，采用磁性分离酶联免疫法检测其中的促卵泡激素（FSH）、黄体生成激素（LH）、雌二醇（E2）、孕酮（P）水平。同时，采用气相色谱附电子捕获器（GC—ECD）方法检测产妇静脉血中有机氯农药的残留水平。[结果]①有机氯农药污染区产妇静脉血中六六六和DDT的8种主要代谢产物在低、中、高残留组均有不同程度检出，总六六六的检出量明显高于总DDT，低残留组为4.1与0.0μg/L，中残留组为13．2与5．5μg/L，高残留组为50.0与41．8μg/L；各组总有机氯的检出量均数分别为〈0．005、4．95、24.10、98．70μg/L，经统计学检验差异有显著性（P〈0.05）。（参产妇血中总有机氯残留水平与产妇血和脐带血中FSH、LH、E2和P的改变有关，并呈现剂量-效应关系（P〈0．05）。③相关分析表明，产妇血和脐带血中FSH、LH、E2和P水平呈现明显的相关关系；产妇血中总有机氯残留水平与产妇血中E2和P呈现负相关（r=-0．5158，P=0．0238；r=-0．6491，P=0.0026）。[结论]人体内有机氯农药残留可能与血中生殖激素水平的改变有密切关系。     

Pesticide residue on/in the washed skin and its potential contribution to dermal toxicity

Washing the skin of humans or experimental animals after exposure to a pesticide or other chemical may leave a major portion of the dose on/in the washed skin. Questions have been raised as to whether this skin residue can contribute to the toxicity of a pesticide by continued post-wash absorption. In a set of 19 pesticides tested in the rat to determine the fate of this skin residue, absorption from the washed skin continued in 15 at all doses tested, continued in 2 pesticides at only some of the doses tested and did not continue in 2 volatile pesticides. However, only nine pesticides showed an increase in systemic concentration following absorption from the washed skin, which can be considered indicative of potential increased toxicity. The time of occurrence and magnitude of the increase varied with chemical and dose, being a combination of rate and magnitude of absorption and rate and magnitude of excretion of the absorbed chemical. Similar patterns of continued absorption of skin residue may be expected to occur in humans.     

甘草中有机氯类农药残留量的毛细管气相色谱测定

目的　对甘草中15种有机氯农药的毛细管气相色谱测定方法的研究。方法　样品经有机溶剂超声提取、Florisil硅土色谱柱净化后,采用不分流进样方式,用DB-5弹性石英毛细管柱经柱程序升温技术分离, 并用电子捕获检测器检测,外标法计算含量。结果　三水平的平均回收率为74.7%～119.2%,RSD为0.7%～18.9%;被测样品中均含有不同程度的农药残存。结论　本法简便,重复性及净化效果好,可用于甘草中15种有机氯农药的残留量检测。     

Neuropsychiatric evaluation in subjects chronically exposed to organophosphate pesticides.

Long-term exposure to low levels of organophosphate pesticides (OP) may produce neuropsychiatric symptoms. We performed clinical, neuropsychiatric, and laboratory evaluations of 37 workers involved in family agriculture of tobacco from southern Brazil who had been exposed to OP for 3 months, and in 25 of these workers, after 3 months without exposure to OP. Plasma acetylcholinesterase activity levels of all subjects were within the normal range (3.2 to 9.0 U/l) and were not different between on- and off-exposure periods (4.7 +/- 0.9 and 4.5 +/- 1.1 U/l, respectively). Clinically significant extrapyramidal symptoms were present in 12 of 25 subjects, which is unexpected in such a population. There was a significant reduction of extrapyramidal symptoms after 3 months without exposure to OP, but 10 subjects still had significant parkinsonism. Mini-mental and word span scores were within the expected range for this population and were not influenced by exposure to OP. Eighteen of the 37 subjects (48%) had current psychiatric diagnoses in the first interview (13 with generalized anxiety disorder and 8 with major depression). Among the 25 subjects who completed both evaluations, the total number of current psychiatric diagnoses, after 3 months without using OP, dropped from 24 to 13 and the number of affected individuals with any psychiatric diagnosis dropped from 11 to 7. In conclusion, this study reinforces the need for parameters other than acetylcholinesterase activity to monitor for chronic consequences of chronic low-dose OP exposure, and it suggests that subjects have not only transient motor and psychiatric consequences while exposed, but may also develop enduring extrapyramidal symptoms.     

长期接触有机磷农药对机体血液指标的影响

目的观察分析南京市某有机磷农药生产企业人员外周血象（包括WBC、PLT、RBC和Hb）、丙氨酸转氨酶（ALT）和胆碱酯酶（CHE）结果的变化情况,探讨不同工种、不同工龄、不同性别与研究指标之间的关系,为减少职业危害提供科学依据。方法对2013年某有机磷农药生产企业1 138名人员和某外厂692名未接触有机磷农药的工人进行外周血象、ALT和CHE检测分析。结果有机磷组的WBC为（6.0±1.47）×10^9/L,PLT为（158.2±52.29）×10^9/L,RBC为（4.59±0.49）×10^12/L,Hb为（137.3±15.93）g/L,ALT为（24.9±19.78）U/L,CHE为（248.3±85.43）U/L,均在正常参考范围内;但WBC、PLT、RBC、Hb和CHE均低于对照组,差异有统计学意义（均P〈0.01）。不同工种间,PLT、Hb、RBC、ALT和CHE的差异有统计学意义（P〈0.01）,操作工的WBC为（5.97±1.47）×10^9/L,PLT为（155.7±51.55）×10^9/L,RBC为（4.58±0.49）×10^12/L,Hb为（137.1±16.0）g/L,ALT为（24.1±17.33）U/L,CHE为（236.3±86.06）U/L,均低于管理人员,差异均有统计学意义。随着接害工龄的增加,血液检查的各项指标有逐渐降低的趋势,其中,5-15 a组的CHE为（213.6±83.85）U/L,RBC（4.49±0.52）×10^12/L,Hb为（133.9±16.99）g/L,显著低于〈5 a组,差异有统计学意义。CHE的异常率在性别间差异有统计学意义。结论长期接触有机磷农药对生产工人的外周血象,ALT和CHE有一定的负面影响,对工龄5-15年的影响尤为明显。     

Evaluation of cytotoxicity and genotoxicity of pesticide mixtures on lymphocytes

The cytotoxicity and genotoxicity of pesticide mixtures viz. endosulfan?+?chlorpyrifos, chlorpyrifos?+?profenofos, and endosulfan?+?profenofos were evaluated on cultured human peripheral blood lymphocytes using assays for cell viability, and genotoxicity using chromosomal aberrations test and comet assay. The LC₅₀ values for cytotoxicity were 3.50?μM, 4.18?μM, and 10.5?μM for profenofos, endosulfan, and chlorpyrifos respectively. When combined in equimolar concentrations, the LC₅₀ values for cytotoxicity were 1.4?μM, 1.8?μM, and 2.0?μM for endosulfan?+?chlorpyrifos, chlorpyrifos?+?profenofos, and endosulfan?+?profenofos, respectively. Higher concentrations of individual pesticides (0.5–4.0?μM) but very low concentrations of pesticide mixtures caused significant DNA damage. Additive index values indicated a synergistic effect of toxicity for endosulfan?+?chlorpyrifos combination (1.12 TTU). The binary mixture of chlorpyrifos?+?profenofos showed an additive toxicity (0.46 TTU) while an antagonistic effect was observed for endosulfan?+?profenofos combination. Synergism could be due to these complementary pesticides simultaneously acting in different ways, magnifying their efficacy, whereas an additive interaction would imply that the chemicals are acting by the same mechanism and at the same target. Analysis of toxicity of pesticide mixtures may serve as important biomarker for occupational and household exposure to pesticides, with different modes of action.     

Work with pesticides and organophosphate sheep dips

Pesticides are an important hazard in agriculture. In developed countries their use is strictly regulated. Risk assessment for new pesticides includes comparison of the potential exposures of spray operators and other farm workers with a reference value. Usually, this is derived from toxicological studies in animals with allowance for the uncertainties in extrapolating between and within species. Older pesticides undergo periodic reviews, for which epidemiological data may also be available. Unintentional fatal poisoning by pesticides is extremely rare in Britain. Documented reports of non-fatal acute poisoning are also uncommon, but there may be substantial under-ascertainment of minor incidents. Pesticides have been linked with various chronic diseases, but few associations have been clearly established. A particular concern recently in Britain has been the possibility that organophosphate insecticides can cause chronic neuropsychiatric illness.     

Residential Pesticides and Childhood Leukemia: A Systematic Review and Meta-Analysis

Objective

We conducted a systematic review and meta-analysis of previous observational epidemiologic studies examining the relationship between residential pesticide exposures during critical exposure time windows (preconception, pregnancy, and childhood) and childhood leukemia.

Data sources

Searches of MEDLINE and other electronic databases were performed (1950–2009). Reports were included if they were original epidemiologic studies of childhood leukemia, followed a case–control or cohort design, and assessed at least one index of residential/household pesticide exposure/use. No language criteria were applied.

Data extraction

Study selection, data abstraction, and quality assessment were performed by two independent reviewers. Random effects models were used to obtain summary odds ratios (ORs) and 95% confidence intervals (CIs).

Data synthesis

Of the 17 identified studies, 15 were included in the meta-analysis. Exposures during pregnancy to unspecified residential pesticides (summary OR = 1.54; 95% CI, 1.13–2.11; I² = 66%), insecticides (OR = 2.05; 95% CI, 1.80–2.32; I² = 0%), and herbicides (OR = 1.61; 95% CI, 1.20–2.16; I² = 0%) were positively associated with childhood leukemia. Exposures during childhood to unspecified residential pesticides (OR = 1.38; 95% CI, 1.12–1.70; I² = 4%) and insecticides (OR = 1.61; 95% CI, 1.33–1.95; I² = 0%) were also positively associated with childhood leukemia, but there was no association with herbicides.

Conclusions

Positive associations were observed between childhood leukemia and residential pesticide exposures. Further work is needed to confirm previous findings based on self-report, to examine potential exposure–response relationships, and to assess specific pesticides and toxicologically related subgroups of pesticides in more detail.