Adjustments of the Pesticide Risk Index Used in Environmental Policy in Flanders

Indicators are used to quantify the pressure of pesticides on the environment. Pesticide risk indicators typically require weighting environmental exposure by a no effect concentration. An indicator based on spread equivalents (ΣSeq) is used in environmental policy in Flanders (Belgium). The pesticide risk for aquatic life is estimated by weighting active ingredient usage by the ratio of their maximum allowable concentration and their soil halflife. Accurate estimates of total pesticide usage in the region are essential in such calculations. Up to 2012, the environmental impact of pesticides was estimated on sales figures provided by the Federal Government. Since 2013, pesticide use is calculated based on results from the Farm Accountancy Data Network (FADN). The estimation of pesticide use was supplemented with data for non-agricultural use based on sales figures of amateur use provided by industry and data obtained from public services. The Seq-indicator was modified to better reflect reality. This method was applied for the period 2009-2012 and showed differences between estimated use and sales figures of pesticides. The estimated use of pesticides based on accountancy data is more accurate compared to sales figures. This approach resulted in a better view on pesticide use and its respective environmental impact in Flanders.     

Approaches to genetic control for the use of pesticides

Analysis of data available in literature has shown that 65% of 400 pesticides studied for their mutagenicity exert a mutagenic effect on any test-object. The number of revealed mutagens approaches 100% when four or more test-objects are used. Recommendations for quantitative estimation of genetic risk worked out under conditions of model experiments with standard mutagens are not available for pesticides since they are slight mutagens. The necessity for genetic stage-by-stage monitoring of pesticide use is substantiated. This monitoring should be carried out at the stage of experimental studies by means of classifications by the degree of potential mutagenic danger (the method is described) and at the stage of ecological and genetic investigations--by means of the regulation for application with due regard for the summary mutagenic background.     

Toxicity of Fastac 10 EC, a pyrethroid insecticide, to Paramecium primaurelia and Tubifex sp.

The pyrethroide, Fastac 10 EC was tested on the paramecia and Tubifex sp. The results showed that both tests are valid for estimation of the toxicity of the pesticide. However, the Paramecium test is more sensitive when one is investigating the direct toxicity of the compound. The great validity of the Tubifex test lies in the possibility of tracing the teratogenic effects of the pesticides.     

细胞电生理技术在昆虫抗药性研究中的应用

害虫几乎对所有化学农药及Bt等生物农药都产生了抗性。离子通道是多种杀虫剂的作用靶,因此作为研究离子通道基本手段的电压钳与膜片钳技术在害虫抗性检测与抗性机理研究中越来越受到重视。该文综述了细胞电生理技术在害虫抗性机理、杀虫剂作用机理以及药物筛选中的应用。     

Why demographic and modeling approaches should be adopted for estimating the effects of pesticides on biocontrol agents

Recent studies have shown that simplistic measures of toxicity such as the LC₅₀ do not provide enough information about the actual effects that may occur in pesticide-exposed populations over longer time periods than a few days. In this paper we discuss the use of demography and population modeling for estimation of pesticide effects on pest and beneficial species and argue that these new approaches are essential to further our understanding of the potential impacts that pesticides might have on both pest and beneficial species such as biological control agents.     

Phytoremediation of groundwater contaminated with pesticides using short-rotation willow crops: A case study of an apple orchard

The occurrence of pesticides in groundwater represents an important health issue, notably for population whose drinking water supply source is located in agricultural areas. However, few solutions have been considered with regard to this issue. We tested the efficacy of a vegetal filtering system made of shrub willows planted at a high density (16,000 plants ha^?1) to filter or degrade pesticides found in the groundwater flowing out of an apple orchard. Ethylene urea (EU), ethylene thiourea (ETU), tetrahydrophthalimide (THPI), atrazine, and desethylatrazine were monitored in the soil solution in willow and control plots over one growing season. ETU and atrazine concentrations were lower in the willow plots relative to the control plots, whereas desethylatrazine concentration was higher in the willow plots. No significant difference was detected for EU and THPI. Furthermore, pesticide concentrations displayed complex temporal patterns. These results suggest that willow filter systems can filter or degrade pesticides, notably ETU and atrazine, and could be used for phytoremediation purposes. Yet, this potential remains to be quantified with further studies using experimental settings allowing more estimation in time and space.     

Influence of organochlorine pesticides on physiological potency of cultured granulosa cells from bovine preovulatory follicles

In the present study the direct effect of Dichlorodiphenyltrichloroethane (DDT), Methoxychlor (MXC) and Hexachlorocyclohexane (gammaHCH) was investigated on the DNA synthesis (measured by [3H]thymidine incorporation); proliferation (determined by colorimetric MTT[3-[4,5-dimethylthiazol-2yl]-2,5-diphenyl tetrazolium bromide] assay); and steroidogenesis (estradiol 17beta, progesterone determination) of granulosa cells during in vitro culture. The cells were aspirated from preovulatory follicles in PMSG-treated heifers. They were cultivated in phenol red and serum (0.1% FCS) RPMI 1640 medium without or with the 3 pesticides in different concentrations. In summary, the results showed differential inhibition of parameters named above by these pesticides (gammaHCH < MXC < DDT) in comparison with vehicle-treated control. Progesterone synthesis was more inhibited than estradiol 17beta production by 3 chemicals, which resulted from the loss of viability of cells indicated by estimation of cell-shape-factor and viability of cells. Besides the inhibitory effect, there was a stimulatory effect of low concentrations of DDT and MXC on [3H]thymidine incorporation and proliferation.     

Using reports of bee mortality in the field to calibrate laboratory-derived pesticide risk indices

Mounting evidence suggests that pollinators worldwide are experiencing dramatic population declines, and exposure to pesticides is one of the factors that can account for this. By making use of a database containing more than two decades of honey bee (Apis mellifera) hive poisoning incidents from the United Kingdom (Wildlife Incident Investigation Scheme [WIIS]) and corresponding pesticide use surveys, we attempted to explain honey bee poisoning incidents in the field using models derived from pesticide use information, laboratory-generated bee toxicity data (defined as a hazard ratio; application rate divided by LD(50)), and physico-chemical properties of the applied pesticides. Logistic regression analyses were used to assess the relationship between honey bee poisoning incidents in the field and these parameters. In analyzing models with multiple dimensions, we selected the best model by the best subset method, an iterative method based on maximum likelihood estimation, and Akaike's information criterion. Results suggested that the size of the area treated and hazard ratios calculated from application rates and oral or contact toxicity (but the latter especially) can be used to predict the likelihood that honey bee mortality will occur. Model predictions also suggest that some insecticides carry an extreme risk for bees, despite the lack of documented incidents.     

Prenatal exposure to pesticides: analysis of human placental acetylcholinesterase, glutathione S-transferase and catalase as biomarkers of effect.

Pre- and perinatal exposure to pesticides is deleterious on foetal and neonatal development, but information regarding possible effects on environmental low-dose exposure to pesticides is scarce. Most epidemiological studies of the health effect of pesticides have been based on self-reported information. However, detailed information on past pesticide use is difficult to reconstruct. This is a current study conducted among pregnant mothers attending a delivery care and perinatal programme at a public hospital. The study investigates biomarkers of early effects in placentas from women living in an area with an intensive use of pesticides in the northern part of Patagonia, province of Río Negro, Argentina, and it assesses the consistency of the information provided by self-reports. The study confirms that placental acetylcholinesterase and catalase activities are significantly associated with periods of organophosphorus pesticides application, while glutathione S-transferase is not affected. We found a positive correlation between environmental exposure to organophosphorus pesticides and carbamate insecticides and newborn head circumference. The findings provide a further indication of a link between placenta acetylcholinesterase and catalase activity and prenatal exposure to pesticides in population studies. Both placenta enzymes may be used as biomarkers in health surveillance programmes for early diagnosis of exposure related alterations produced by organophosphorus pesticides and carbamate pesticides.     

Prenatal exposure to pesticides: analysis of human placental acetylcholinesterase,glutathione S-transferase and catalase as biomarkers of effect

Pre- and perinatal exposure to pesticides is deleterious on foetal and neonatal development, but information regarding possible effects on environmental low-dose exposure to pesticides is scarce. Most epidemiological studies of the health effect of pesticides have been based on self-reported information. However, detailed information on past pesticide use is difficult to reconstruct. This is a current study conducted among pregnant mothers attending a delivery care and perinatal programme at a public hospital. The study investigates biomarkers of early effects in placentas from women living in an area with an intensive use of pesticides in the northern part of Patagonia, province of Río Negro, Argentina, and it assesses the consistency of the information provided by self-reports. The study confirms that placental acetylcholinesterase and catalase activities are significantly associated with periods of organophosphorus pesticides application, while glutathione S-transferase is not affected. We found a positive correlation between environmental exposure to organophosphorus pesticides and carbamate insecticides and newborn head circumference. The findings provide a further indication of a link between placenta acetylcholinesterase and catalase activity and prenatal exposure to pesticides in population studies. Both placenta enzymes may be used as biomarkers in health surveillance programmes for early diagnosis of exposure related alterations produced by organophosphorus pesticides and carbamate pesticides.     

农药对捕食性天敌的影响研究进展

捕食性天敌在害虫的自然控制方面起着重要作用。当害虫大发生时,需使用化学农药来进行有效控害,但化学农药会对捕食性天敌的生存造成影响。因此,了解农药对捕食性天敌的影响有利于协调化学防治和生物防治的关系。大部分农药对捕食性天敌的生长发育和繁殖表现为抑制作用,但有的为促进作用。在农药的干扰下,多数捕食性天敌的信息识别能力会降低,少部分会通过提高雄虫接收性信息素的能力或增加雌虫性信息素的释放来诱导求偶行为、增加交配频率。有的杀虫剂会影响捕食性天敌的捕食行为及捕食功能,部分杀虫剂会直接使其捕食功能模型由Holling-Ⅱ型转变为Holling-Ⅰ型。在农药胁迫下,捕食性天敌会产生抗药性,其解毒酶活性升高、保护酶活性改变及靶标部位敏感性下降可能是抗药性产生的机理。农药对捕食性天敌的影响研究在协调害虫化学防治和生物防治中有着重要的理论和现实意义,可以有效地推进捕食性天敌在害虫综合治理中的应用。     

Pesticide or wastewater: Which one is a bigger culprit for acute health symptoms among vegetable growers in Pakistan's Punjab?

Literature highlights harmful effects of pesticides and untreated wastewater use on farmers' health but none of the studies explore the magnitude of deleterious health effects simultaneously. The objective of the study is to quantify pesticide and untreated wastewater induced health symptoms among vegetable growers and to investigate which one is a bigger culprit. A sample of 830 vegetable growers was selected by stratified random sampling from three major vegetable growing districts of Pakistan's Punjab. A two stage estimation technique is employed to estimate unbiased health effects of vegetable growers after controlling for pesticide endogeneity. The results demonstrate that both untreated wastewater and pesticide quantities are responsible for acute symptoms, but comparison of their scaled coefficients indicates that wastewater is twofold responsible for acute symptoms than pesticide. To minimize these negative effects, a policy of untreated disposal of wastewater in peri-urban areas for crop production needs to be re-designed. The installation of a treatment plant by collecting pollution premium from untreated wastewater emitters seems to be the most sustainable and practically viable option. It is also observed that pesticide is contributing to farmers' acute symptoms; hence, awareness campaigns about judicious and safe use of pesticides may help to mitigate acute symptoms.     

植物-微生物联合修复化学农药污染土壤的研究进展

化学农药的高毒性、生物积累性和扩散性极易对环境及人类健康造成危害,环境中化学农药的去除尤为重要。植物-微生物联合修复技术因其高效、环境友好和修复成本低等优点受到越来越多的关注,植物-微生物联合修复化学农药污染土壤是一种很有前景的方法。植物为根际和内生细菌提供养分,而细菌通过化学农药的降解和解毒来支持植物生长。本文综述了影响化学农药在植物体内吸收和转运的因素以及植物-微生物修复技术的原理,并讨论了植物与微生物在化学农药污染土壤修复中的协同效应,并对植物-微生物联合修复法在化学农药污染土壤修复中的应用前景进行了展望。     

Dual-level toxicity assessment of biodegradable pesticides to aquatic species

The use of ecological models to assess the effects of pesticides on the structure and function of aquatic ecosystems is of growing interest. Of utmost concern is assessment of pesticides that have the potential to biodegrade into metabolites that are as toxic as the parent pesticide. In this work, a mathematical model to predict and evaluate the effect of two pesticides on the population of aquatic biospecies where both pesticides are bio-available in water and sediments with one of the pesticides capable of biodegrading into the other but not vice versa is formulated and analyzed. Conditions for nonlinear stability, instability and Hopf-bifurcation are obtained. The model undergoes a Hopf-bifurcation when the rate of discharge of pesticides crosses a critical value, so that the population of the aquatic species follows an oscillatory pattern. Four hypotheses involving the concentration of the pesticides and the population of the aquatic species where qualitatively investigated: the aquatic species will completely die out with time, the population of the aquatic biospecies will remain under certain conditions, the pesticide will continually remain in water and there will be a periodic variation in the population of the aquatic species over time. Results also indicate that the biodegradation potential of one of the pesticides had significant effect on the population dynamics of the aquatic species.     

Dietary Intake of Pesticides Based on Vegetable Consumption in Ismailia,Egypt: A Case Study

The objective of this study was to assess pesticide residues in tomatoes, cucumbers, peppers, strawberries, and potatoes collected from local markets in Ismailia, Egypt, and to assess dietary intake and health risk implications of pesticide residues through food consumption. Vegetable selection was based on their popularity and consumption. Selection of pesticides was based on their impact on humans, and on their heavy use. The majority of the analyzed samples contained detectable levels of pesticides. Residues of some organophosphorus pesticides, including malathion, ethion, and profenofos and some pyrethroid pesticides such as fenpropathrin and cypermethrin were found in some samples at concentration equal to or exceeding their European Union's maximum residue limits (EU-MRLs). The fungicide bupirimate detected in potato samples exceeded the EU-MRL by 1500%. Phentohate and profenofos were the most frequently detected pesticides in 30 and 27% of analyzed samples, respectively. Data were used to estimate the potential health risks associated with exposure to these pesticides by ingestion of food. Estimated daily intakes (EDIs) of pesticides ranged from 0.03% to 40% of the acceptable daily intakes (ADIs), depending on pesticide concentration and vegetable consumption. Overall, the EDIs of the different pesticides from vegetable consumption are not considered a public health problem.     

多种农药与次氯酸钠、高锰酸钾和高铁酸钾的反应活性

为探究4类,10种广泛使用的农药(苯氧羧酸类,芳香酸类,取代脲类和烟碱类)与3种氧化剂(次氯酸钠,高锰酸钾和高铁酸钾)的反应活性,本研究在温度(25±2)℃、pH值为8的条件下,分析10种农药分别与3种氧化剂NaClO、KMnO4、K2Fe O4在不同浓度下的反应活性,采用HPLC检测法,对比降解效能,探究氧化剂性质与有机物结构导致的反应活性的差异。实验结果表明,不同种类农药的结构性质对反应活性有重要影响,3种氧化剂的氧化降解能力有明显差异。苯氧羧酸类和芳香酸类农药结构较简单,并含有稳定的苯环或吡啶环结构,氧化降解较困难。取代脲类和烟碱类农药结构较复杂,氧化剂可攻击其不饱和官能团,反应活性较高。NaClO对取代脲类农药的降解率明显优于其他2种氧化剂,3种氧化剂对烟碱类农药的氧化降解效果依次为NaClO>KMn O4>K2Fe O4。研究多种农药与次氯酸钠、高锰酸钾和高铁酸钾的反应活性对降解去除水体中的农药残留对水环境的治理具有重要意义。     

有机磷农药降解菌及其基因工程研究新进展

有机磷农药是目前我国使用量最大的农药,对农业的发展有重要的作用,但同时造成了严重的环境污染.利用微生物及其产生的降解酶来降解农药是行之有效的方法.随着分子生物学技术的深入利用,农药的微生物降解已在基因工程领域取得了很大进展.本文综述了有机磷农药降解微生物的筛选、降解酶和基因的克隆、基因工程菌的构建以及应用等几个方面的研究进展.     

Adaptation to the action of several teratogens as a consequence of preliminary administration of pesticides to females]

The effect of DDT and lindane pesticides on the intensity of the teratogenic action of sodium acetylxalicylate (SA) and of the cabomate benlate group of pesticides was studied on Wistar rats given the mentioned pesticides from the onset of pregnancy. The teratogens were administered on the 10th and the 12th days of gestation, respectively. Preliminary administration of these pesticides was found to weaken the teratogenic and the embryotoxic action of benlate given in a dose of 250 mg/kg, and of SA administered in a dose of 400 mg/kg. When SA was given in a dose of 600 mg/kg preliminary administration of the pesticides decreased the postimplantation mortality of the embryos, but the number of fetuses with developmental anomalies was the same as in the isolated action of the preparation given in this dose.     

利用人工湿地去除农业径流中农药的研究进展

人工湿地对农业径流污染物去除效果显著,已成为控制农业径流污染的有效措施.本文结合国内外研究,介绍了当前水体农药污染的现状;从物理、化学及生物角度阐述了人工湿地对农药的去除机理和关键过程;归纳总结了人工湿地对农药的去除效率,指出人工湿地对农药的去除效率随农药类型的不同而差异较大:农药的平均去除率,按农药用途分为杀虫剂＞杀菌剂＞除草剂,按农药化学结构分为拟除虫菊酯类>有机磷类>三唑类＞酰胺类＞三嗪类＞脲类;综合考虑,潜流人工湿地在农药去除方面的效果优于表面流人工湿地.在此基础上分析了农药理化性质、人工湿地工艺类型及运行参数、进水中农药浓度、湿地植物等因素对农药在人工湿地中去除的影响.最后指出了当前研究中存在的问题,并提出了研究展望.