Tolerance setting process in the U.S. Environmental Protection Agency

The U.S. Environmental Protection Agency (EPA) is responsible for setting tolerances for pesticide residues in food, under the authority of the Federal Food, Drug, and Cosmetic Act. The residue chemistry data required to set tolerances include metabolism in plants and animals, analytical methods, magnitude of the residue, and concentration in processed foods. A key aspect of tolerance-setting procedures is the identity of the residue in the matrix of concern; without knowledge of the chemical moieties that occur as residues, it is impossible to develop suitable methods or generate meaningful residue data. For new chemicals, EPA carries out a single-laboratory validation of the analytical method needed to generate residue data and to enforce tolerances. Tolerance enforcement methods need to be rapid and inexpensive and to use commercially available equipment and reagents. Methods are more complex for many newer pesticides, which are polar compounds that leave low levels of residue. EPA now requires that the registrants of older pesticides, for which methods are not acceptable by today's standards, must develop better methods.     

Comparing conventional and biotechnology-based pest management

Pest management has changed dramatically during the past 15 years by the introduction of transgenes into crops for the purpose of pest management. Transgenes for herbicide resistance or for production of one or more Bt toxins are the predominant pest management traits currently available. These two traits have been rapidly adopted where available because of their superior efficacy and simplification of pest management for the farmer. Furthermore, they have substantially reduced the use of environmentally and toxicologically suspect pesticides while reducing the carbon footprint of pest management as reduced tillage became more common, along with fewer trips across the field to spray pesticides. The most successful of these products have been glyphosate-resistant crops, which cover approximately 85% of all land occupied by transgenic crops. Over-reliance on glyphosate with continual use of these crops has resulted in the evolution of highly problematic glyphosate-resistant weeds. This situation has resulted in some farmers using weed management methods similar to those used with conventional crops. Evolution of resistance has not been a significant problem with Bt crops, perhaps because of a mandated resistance management strategy. Transgenic crops with multiple genes for resistance to different herbicides and resistance to additional insects will be available in the next few years. These products will offer opportunities for the kind of pest management diversity that is more sustainable than that provided by the first generation of transgenic crops.     

Gas chromatographic-electron capture detection method for determination of 29 organochlorine pesticides in finished drinking water: collaborative study

A joint U.S. Environmental Protection Agency/AOAC interlaboratory method validation study was conducted on EPA Method 508, Determination of Chlorinated Pesticides in Water by Gas Chromatography with an Electron Capture Detector, to determine the mean recovery and precision for analyses of 29 pesticides in reagent water and finished drinking water. The study design was based on Youden's nonreplicate plan for collaborative tests of analytical methods. The waters were spiked with 29 pesticides at 6 concentration levels, as 3 Youden pairs. Eleven volunteer laboratories extracted the spiked test waters with methylene chloride, performed a solvent exchange with methyl tert-butyl ether, and analyzed an aliquot of each extract by gas chromatography with electron capture detection. Results were analyzed using an EPA computer program, interlaboratory Method Validation Study (IMVS), which measured recovery and precision for each of the 29 pesticides and compared the performance of the method between water types. Method 508 was judged acceptable for all analytes tested. Only 3 analytes (alpha-chlordane, 4,4'-DDE, and methoxychlor) exhibited practical significant matrix effects. The method has been adopted official first action.     

控制棉铃虫的生态学途径--病毒生防

棉铃虫是危害我国农业生产的主要害虫，危害棉花等多种作物。由于它对化学农药的抗性增强，单纯依靠化学农药难以控制该种害虫的发生和危害。因此，开展生态控制途径的研究具有重要意义。棉铃虫病毒杀虫剂是我国第一个成功开发的昆虫病毒杀虫剂。本文主要介绍棉铃虫核型多角体病毒（NPV）的基本特性、在环境中的稳定性、病毒生防技术及其效果。     

党参化肥农药减施增效栽培技术规程

化肥农药减施增效可助力党参产业绿色健康发展。为更好地指导甘肃省党参种植生产中化肥和农药施用,针对党参种植生产中化肥农药过量施用、养分利用率低、防控过度依赖化学农药等问题,经过多年试验研究和生产示范,从范围、规范性引用文件、术语和定义、产地环境、化肥减施、种苗移栽、田间管理、主要病虫害防控、采收等方面总结提出了党参化肥农药减施增效栽培技术规程。     

Comparison of regulatory estimates of drinking water concentrations with monitoring data

Currently, regulatory practice in the United States is to estimate potential concentrations in drinking water from surface water by using an index reservoir scenario. This approach extrapolates results from the modeling of a single field with maximum application rates to the watershed scale, based on a percent crop area estimate. Since 1998, Bayer CropScience and its predecessor companies have conducted drinking water monitoring studies with a number of different compounds. The results from these studies show that the index reservoir scenario greatly overpredicts residues in surface water. The most important factor is the overestimation of use within a watershed. Other factors contributing to the overestimation of concentrations are the conservative procedures used to obtain the chemical fate related input parameters and the simplified hydrology. A new procedure based on the USGS WARP model, being developed by a group of scientists from the EPA, USGS, USDA, and industry, will provide more realistic estimates of concentrations of pesticides and their metabolites in drinking water.     

农业景观害虫控制生境管理及植物配置方法

集约化农业生产过程中,化学农药所带来的大量环境问题日益引起关注。为减少农药的投入及其所产生的环境负效应,生物防治害虫的方法在国内外得到了更多的关注与发展。生境管理是一种有利于天敌群落发展,而不利于害虫种群增长的保护性生物防治方法,其实质是通过为自然天敌提供诸如花蜜、替代猎物或寄主、躲避不利干扰的庇护所等资源,将农业景观中天敌的害虫控制服务和功能最大化,或者通过构建不适宜害虫取食和繁殖的环境条件起到抑制或阻碍害虫发展的作用。本文在参阅国内外文献的基础上,阐述了生境管理控制害虫的机理,并总结国外生物防治的实践经验以及近些年国内外的相关研究,概括提出田间尺度上害虫生物防治的非作物生境及作物生境的建设和植物配置方法,为通过生境管理提升农业景观中害虫生物防治生态系统服务提供参考。     

Assessment of the bacteriological quality of rural groundwater supplies in Northern West Virginia

A bacteriological survey was performed on 155 untreated, individual, rural groundwater supplies which included drilled wells, dug wells, and springs. Of these, 105 exceeded the Environmental Protection Agency (EPA) maximum contaminant level of one total coliform per 100 mL. Repeat sampling for 87 of the unacceptable 105 supplies indicated that 76 again exceeded the EPA standard limit. Masked coliforms were detected through confirmation tests in 11 water supplies that exhibited excessive noncoliform colonies (> 50 CFUs/membrane filter). Also, 48% of the supplies contained fecal coliforms and 62% contained fecal streptococci. Bacterial densities were related to the type of water supply with drilled wells containing fewer total coliforms, fecal coliforms, fecal streptococci, and heterotrophic plate count bacteria than dug wells or springs. Water supplies that were shallower, older, and lacking adequate casing characteristically were more heavily contaminated with sanitary indicator bacteria than supplies that were deeper, of more recent construction, and with sufficient casing.     

化学农药施用技术与粮食安全

化学农药在保证粮食供应方面发挥了重要作用,这是粮食安全的传统意义。但是农药大量投入导致农产品中农药残留超标,影响了粮食安全的另一个方面。化学农药对农产品的负面影响与农药的施用方法有密切的关系。发达国家在改善环境质量、提高农产品品质的同时,建立了完善的农药使用和管理法规,并通过农药施用技术改造,大大提高了农药的利用率,从而基本解决了农药环境污染和农产品农药残留超标的问题。我国在农药施用过程中,由于长期忽视施用质量的提高,加之缺乏相应的管理措施,农药对病虫草害的防治效果一直是以农药的大量投入来保证的,对农产品质量造成了很大的影响。要解决农药的使用问题,首先须通过行政管理和立法限制单位土地面积上农药的施用量,其次建立农户农药购买登记制度,保证农户实际所用农药不会超过允许使用量,最后加强农药施用者的培训,培训合格后发给操作证,持证施用农药。确保这3个环节的落实,可激发农户农药施用技术的改进,使有限投入的农药发挥最大的效用,减少农药用量,缓解农药与环境及农产品质量之间的矛盾     

Soil fauna in sheep-grazed hill pastures under organic and conventional livestock management and in an adjacent ungrazed pasture

Organic pasture management includes a focus on mixed livestock grazing, restrictions on nutrient inputs and livestock pest control. These are all factors which influence the environment of soil invertebrates. In this study, soil macrofauna, mesofauna and microfauna were collected from duplicate 11 and 20 year old organic and conventional legume-based sheep-grazed pasture systems. Pastures in both systems had received the same annual input of reactive phosphate rock and elemental sulphur and were stocked with the same numbers of sheep. The major difference between the two systems was absence of the chemical control of livestock pests on the organic system, resulting in lower sheep liveweights. Two ungrazed pastures which had not received any nutrient inputs for 20+ years were also sampled as part of the study to provide an additional contrast.No significant differences in either the diversity or abundance of the soil invertebrate community were found between the organic and conventional systems, despite the use of chemicals in the conventional system. The lack of difference suggests that many of the observed and reported responses to organic management reflect altered nutrient inputs and grazing management (which were the same in the current study), rather than the cessation of chemical controls in the organic system. In contrast, the invertebrate community in the unfertilised, ungrazed pasture was distinctly different from both the grazed systems. The ungrazed pasture had a higher diversity with more New Zealand endemic species than the grazed pasture. This included twice as many large Oribatida as soil pore size increased. The lower litter quality from the lack of nutrient inputs in the ungrazed pasture was reflected in both lower earthworm abundance and the Nematode Channel Ratio (indicative of a higher proportion of fungal- than bacterial-feeding nematodes), than the grazed pasture.We conclude that organic management when limited to a comparison of livestock pest control is not beneficial to soil invertebrates. Management practices such as stocking rates and fertiliser regime, by altering the soil physical environment and food resources, are more important in influencing invertebrate populations in this soil. Some would argue these altered management practices are an integral part of an organic production system.     

陇西县玉米病虫害种类及农药使用情况调查

为掌握玉米病虫害发生种类和农药使用情况,制定玉米病虫害防治规范。采用定点调查方法,对陇西县玉米病虫害及农药使用情况进行了调查。调查发现,该县玉米主要病害有茎基腐病、锈病、大斑病和小斑病,虫害有玉米螟、蚜虫、红蜘蛛、蓟马、黏虫和地下害虫等。将农药使用情况录入全国农药信息管理系统进行分析,表明在玉米整个生育期,按其类型,除草剂用量最大,其次为杀虫剂和杀菌剂,生长调节剂用量最小;按毒性,低毒农药用量最大,其次为中毒农药,微毒农药用量最小;按种类,以化学农药为主、生物农药为辅;按农药成分,辛硫磷、莠去津用量较大。     

机油乳剂防治策略对柑橘园害虫天敌群落结构与动态的影响

不同防治策略对果园害虫天敌群落的影响试验结果表明,与果农常规防治策略(主要使用化学合成农药防治害虫)试区相比,机油乳剂防治策略(主要使用机油乳剂防治害虫)试区柑橘害虫天敌群落丰富度较高,且随该防治策略的继续实施而进一步逐年提高,天敌群落均匀度指数较稳定,而天敌群落多样性指数则无明显变化。     

Forestry and soil protection in the UK

Abstract. Protection of soil against common threats to its function are discussed in relation to UK forestry practice. British forestry uses very little fertilizer and pesticides, so the effect of their use on forest soil is minimal. Some soil acidification often accompanies forestry, but there is as yet no evidence that UK forest condition or yield have suffered as a consequence. Proper management of forest operations can control the severity of soil compaction and erosion, and though there is no evidence that either is widespread, more information is required on their occurrence.     

Empirical evaluation of sufficient similarity in dose—Response for environmental risk assessment of chemical mixtures

When toxicity data are not available for a chemical mixture of concern, U.S. Environmental Protection Agency (EPA) guidelines allow risk assessment to be based on data for a surrogate mixture considered “sufficiently similar” in terms of chemical composition and component proportions. As a supplementary approach, using statistical equivalence testing logic and mixed model theory we have developed methodology to define sufficient similarity in dose—response for mixtures of many chemicals containing the same components with different ratios. Dose—response data from a mixture of 11 xenoestrogens and the endogenous hormone, 17ß-estradiol are used to illustrate the method.     

Advances in pesticide environmental fate and exposure assessments

Globalization of markets and the growing world population increase threats of invasive and exotic species and place greater demands on food and fiber production. Pest management in both agricultural and nonagricultural settings employs established practices and new biological, chemical, and management technologies. Pesticides are an essential tool in integrated pest management. Without pesticides a significant percentage of food and fiber crops would be lost, infectious diseases would increase, and valuable native habitats would be devastated. Therefore, it is important to understand the environmental fate of pesticides and assess their potential exposure and associated risks to human health and the environment. This paper summarizes the Advances in Pesticide Environmental Fate and Exposure Assessment symposium held at the 231st National Meeting of the American Chemical Society (Atlanta, GA, 2006). The focus of the symposium was to provide current information on advances in pesticide environmental fate and exposure assessments. Thirty papers were presented on advances ranging from subcellular processes to watershed-scale studies on topics including chemical degradation, sorption, and transport; improved methodologies; use of modeling and predictive tools; exposure assessment; and treatment and remediation. This information is necessary to develop more effective pesticide use and management practices, to better understand pesticide fate and associated exposures and risks, to develop mitigation and remediation strategies, and to establish sound science-based regulations.     

现代信息技术在害虫种群密度监测中的应用

害虫种群密度监测是害虫预测准确度关键，对农田生态系统中害虫综合管理有重要指导意义。该文从传统的害虫监测技术入手，分析了近年现代信息技术在害虫自动化监测中应用的进展，分析了计算机视觉、声音信号、传感器、雷达和遥感等信息技术在害虫密度估算中的优势和存在的问题，指出了计算机视觉技术和传感器技术是具有潜力的监测技术，阐述了现代信息技术在害虫自动化监测的主要方向和实现途径，对未来农田生态系统中害虫预测和综合管理具有重要意义。     

U.S. EPA regulation of plant-incorporated protectants: assessment of impacts of gene flow from pest-resistant plants

The U.S. Environmental Protection Agency licenses pesticide-expressing plants under the authority of the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). Transgenes and their pesticidal products represent pesticides under FIFRA and are referred to as plant-incorporated protectants (PIPs). When sexually compatible wild relatives (SCWR) are sympatric with PIP crops, there is a need to assess the potential for adverse effects to man and the environment resulting from transgene introgression in accord with FIFRA requirements. Genetic compatibility, introgression, weediness of SCWR × PIP hybrids, seed dispersal, and dormancy, among other parameters, as well as effects on other species (herbivores and beneficial insects), all need to be considered as part of the risk assessment for experimental use under Section 5 or registration under Section 3 of FIFRA. EPA is currently developing data requirements and guidance toward addressing potential gene flow impacts from PIPs.     

Technical Recommendations for the Update of the ISO Earthworm Field Test Guideline (ISO 11268-3) (5 pp)

Background, Aim and Scope   Background, Aims and Scope. The earthworm field test firstly was developed by the German Federal Biological Research Centre for Agriculture and Forestry (BBA) for testing of pesticides and later internationally standardised by the International Organization for Standardization (ISO) as a tool for characterizing soil quality. It is mainly used for the assessment of effects of pesticides on earthworms under field conditions. Growing experience has shown that the practical performance of the test can be improved. Main Features: In two meetings organised by the Federal Biological Research Centre for Agriculture and Forestry (Braunschweig, 2002) and later the German Federal Agency for Consumer Protection and Food Safety (Lille, 2005) an ad-hoc working group of experts from various countries and institutions discussed the practical performance and recommendations that should be taken into account in a revised draft following the current ISO guideline after the proposed revision has been approved by voting in the periodical review. Results: The outcome of the discussions and the background of the recommendations of the ad-hoc working group are briefly summarised in this paper. These are mainly methodological details in order to improve the test performance (e.g. by decreasing variability or increasing practicability). Discussion: These recommendations are proposed to be considered for the next update of the current ISO guideline. They should be seen as technical amendments still waiting for their approval by standardisation organisations. Conclusions: Although this method focuses on the assessment of effects of pesticides on earthworms, the recommendations will also be valuable for testing contaminated soils. The recommendations presented may also be a first step for splitting the current guideline into two fields of application, one for testing of chemicals and pesticides (i.e. within the scope of OECD) and another one for testing soil quality (i.e. within the scope of ISO). Perspectives: Nevertheless, there is still a major need for guidance concerning the interpretation of effects determined in such complex field tests.     

Toxicity Studies in a Tobacco Industry Biological Treatment Plant

Tobacco industry wastewater contains some toxic contaminantswhich inhibit the microbial consortium in biological treatmentplants. Investigations carried out showed that the most important sources of these toxic contaminants are nicotine,flavoring chemicals containing glycogen and alcohol, absorbableorganic halogens (AOX), and pesticides from tobacco leaves. Shock loadings of these toxic contaminants inhibit the bacterialactivity during biological treatment. Input of wastewater containing such toxic substances causes decreases in bacteria numbers and reduce the treatment efficiency in the treatmentplant. Viable numbers of floc forming, total and faecal coliform bacteria which are living in a biological treatmentunit (i.e. Biopac) were monitored. Conventional short-term bioassays and enrichment toxicity tests were performed to determine potential toxicity. If the ratio of bacteria numbersgrowing in the enrichment medium compared to control is between0.8 and 1.2, it may be assumed that toxic substances are absent.If this ratio exceeds 1.2, it may be assumed that growth stimulating substances are present. If this ratio is below 0.8,this indicates the presence of toxic substances. The results ofenrichment toxicity studies showed that enough nutrients canstimulate the bacterial growth, or known/unknown sources of toxicity can be inhibit the microbial growth. Furthermore, results of chemical coagulation/flocculation test experimentsshowed that chemical treatment is effective at reducing toxicityand is proposed for biological treatment.     

Research initiatives in the art and science of biopesticide formulations

Recent initiatives by the pesticide regulatory departments of European and North American governments have significantly renewed interest in biopesticide technologies as alternatives for pest management following plans to deregister many chemical pesticides within the next 10 years. The literature is abundant with studies on screening for microorganisms with attributes of biopesticidal activity, however, very few of the authors have considered formulating the microorganisms with commercial applications in mind. A concerted plan in formulation development for biopesticides and bioinoculants by multi-disciplinary teams is required to optimize biopesticide yield, efficacy, storage stability and delivery for this technology to evolve and meet today's agricultural demands.