Duration: 10/01/2010 to 09/30/2015

Administrative Advisor(s):

NIFA Reps:

Non-Technical Summary

Statement of Issues and Justification

Statement of the Problem. The growing demand for food and fiber places greater strain on agricultural production and environmental stewardship. Agrochemicals will remain fundamental as integrated pest management tools to assure an abundant food supply. Inevitably, a significant portion of the applied agrochemicals will be lost to the surrounding environment, where they can adversely affect human and environmental health. The use of conventional and emerging crop protection chemistries in agricultural and urban pest management will require understanding of the fate and effects of agrochemicals, along with mitigation strategies, to minimize their risks to humans and the environment. Renewal of the W-2045 multistate research project will enable multistate collaborations to more effectively advance and transfer science to agricultural and regulatory stakeholders, who require solutions to complex human and environmental health concerns that are beyond the scope for any individual state AES or USDA-ARS unit.

Justification. Over the next quarter century, the world's population is expected to increase by an unprecedented 90 million people per year. The growing demand for food and fiber will place a great pressure on agricultural production and thus growers needs for affordable and efficacious pest management. The need to increase production while reducing associated pressures of agrochemical use on natural ecosystems and human health will pose a difficult challenge for scientists in all areas of basic and applied agricultural research. Although it will be important to provide growers with a variety of biologically based, sustainable production alternatives, the use of agrochemicals will remain essential in pest management. Understanding the effects of agrochemicals on target and non-target species will improve our ability to predict and integrate current and potential pest management strategies, providing environmentally sound and cost effective approaches to pest management. These approaches will also lead to reduced application of pesticides.

Agrochemical use currently exceeds 2 billion kg each year in the United States alone (Aspelin and Grube, 1999). An unquantifiable but considerable portion of this total does not reach or leaves its target; this portion may contaminate air or water, may be transformed in the soil/air/water system, and may come into contact with non-target organisms. The continued responsible use of conventional and emerging crop protection chemistries will require a mechanistic understanding of their fate and effects and integration of this basic knowledge to develop measures to mitigate their adverse effects.

The W-1045 project focuses on building collaborations between land-grant extension specialists, researchers, USDA-ARS scientists, and institution representatives from basic and applied research disciplines to identify and develop research and strategies for understanding and minimizing adverse impacts to humans and the environment resulting from agrochemical use. This multidisciplinary effort enables technology transfer and opportunities for region-wide collaboration on complex environmental fate and effect issues that are beyond the scope of a single state AES or USDA-ARS unit. The outcomes of the W-1045 project are deliverables that can be used by regulatory agencies, growers, agrochemical manufacturers and applicators, and regional agricultural commodity groups for making scientifically sound pesticide management decisions. In partnership with NIFA, other research institutions and agencies, and the Cooperative Extension Service, renewal of the W-1045 multistate research project will further enable meaningful multistate collaborations for problem-solving on high-priority research topics while enhancing environmental stewardship.

A better understanding of off-target movement via volatilization, runoff, and leaching, and the acute and sublethal effects at the ecosystem level is essential for determining risks to biota in the surrounding environment and for characterizing human occupational and non-occupational exposures. Currently, quantifying exposure remains the weak link for evaluating risks associated with human and environmental health. Collaborations between W-1045 scientists at the University of California (Davis and Riverside), Oregon State University, and various state health regulators will have enormous implications in addressing occupational exposures. This work will include environmental and biological monitoring of a variety of work tasks of pesticide handlers and harvesters of treated crops, and residents exposed to pesticides due to indoor exposure. These data will serve to clarify the extent of risk resulting from exposure and provide exposure data for more objective establishment of field entry intervals and the effectiveness of personal protective equipment. Off-target fumigant emissions remain a primary source of non-occupational exposure at the individual and community health level. To reduce non-occupational inhalation exposures, W-1045 members at Washington State University and University of Florida are taking leading roles in developing novel technologies to reduce atmospheric emissions of fumigants while providing adequate dispersion in the root zone to achieve adequate efficacy.

Surface runoff due to irrigation and rain events carries residues of pesticides and other agrochemicals (e. g. , pharmaceuticals used in animal production) into surface aquatic ecosystems, where these compounds may exert acute and sublethal (e. g., endocrine disruption) effects on non-target aquatic organisms, including aquatic species listed as threatened under the Endangered Species Act. Similarly, pesticide residues in soil may induce endocrine disruption effects to soil-dwelling organisms due to the endocrine disruption activity of certain pesticides. Knowledge of the pathways of such exposure is also essential for the development of mitigation strategies to mitigate such nonpoint source contamination. Over the last few years, W-2045 members from University of California Riverside, Kansas State University, Purdue University, Cornell University, University of Hawaii, Oregon State University, and USDA-ARS have greatly expanded their research to address pesticide exposure and effects through non-point source pollution at various levels. The collaboration includes development of sensitive sampling and analytical methods, application of these methods for field monitoring of occurrence of pesticides, pharmaceuticals, and their metabollites, investigation of the ecotoxicological effects using various molecular biology methods, and evaluation of a range of management options to reduce the nonpoint source pollution. The outcomes of this collective effort will provide regulators with information basis for sound regulatory actions, and stakeholders such as growers with options for meeting regulatory requirements and sustaining agricultural practices in environmentally compatible manners.

Turf management (including golf courses, parks and recreation facilities, sports fields, and home residential lawns) typically involves very intensive agrochemical use patterns. Researchers at Mississippi State University will collaborate with USDA-ARS scientists in St. Paul, MN to identify environmental factors and management practices influencing agrochemical losses from turf by runoff and to develop deterministic models to estimate the impact of new and existing chemistries on aquatic systems under suburban management practices. The data gained from this research can be used to identify which compounds exceed the environment's natural attenuative capacity and to develop best management practices to reduce pesticide movement to aquatic systems.

There is growing evidence that historical and current use pesticides may undergo atmospheric long-range transport (including trans-Pacific atmospheric transport) and deposition to remote high latitude and high elevation ecosystems in the U. S. These pesticides may originate in North America or may be present in Eurasian air masses. Atmospheric transport may also serve as an important pathway for pesticide distribution in the increasingly intertwined urban and agricultural communities, contributing to pesticide contamination at the watershed or airshed scale. W-1045 members from Oregon State University and USDA-ARS in Beltsville, MD, will measure historical and current use pesticides to study the fate of these compounds in sensitive, high elevation ecosystems as well as in the agricultural-urban ecosystems. The collaborative expertise, together with novel atmospheric reaction vessels and key instrument resources, will strengthen atmospheric research in evaluating and modeling distributional phenomena and gas-phase chemical reactivity, which is required for assessments of human and environmental exposure. The research results will influence regulatory strategies on the use and effects of pesticides and will aid government agencies in managing exposure to pesticides due to atmospheric transport.

Environmental exposures from the improper disposal of unwanted pesticides and rinse water from pesticide containers and application equipment can trigger regulatory actions that have immediate and irreversible consequences for agriculture. In addition, pesticides such as DDT, although banned several decades ago, are still widespread in the environment owing to their extraordinary persistence. W-1045 members at Cornell University and University of Florida are developing chemically and biologically-based remediation technology that can be utilized to remove highly concentrated pesticide wastewater or to restore environmental compartments contaminated with legacy pesticides.

Since its early beginnings,this project has effectively responded to western region grower and stakeholder concerns for understanding the effects of post-application pesticide transport and fate, and the toxicological implications of agrochemical uses. Today, the work of W-2045 scientists extends well beyond the western region boundary. This growing collaboration among chemists, biologists, toxicologists, and ecologists - with expertise in the basic and applied sciences - remains essential for responding to emerging chemical fate and effect issues in accordance with the need for realistic human and environmental exposure information under the provisions of the Endangered Species Act and the Food Quality Protection Act. The strong collaborations among land-grant university scientists and extension specialists together with USDA-ARS scientists provide a unique amalgamation of research and extension capabilities. This project will continue in its goal to advance science-based strategies to prevent or mitigate adverse impacts on humans and the environment while affording joint research, extension, and training opportunities through multistate collaboration and shared use of key research and educational resources.

Related, Current and Previous Work

Research is needed to elucidate the processes of agrochemical fate and function to maximize efficacy, to determine realistic exposure potentials to biota (including humans) from foliar, soil, water, and airborne agrochemical residues, and to develop exposure mitigation strategies. This research will require (a) more appropriate biomarkers and analytical methods with better sensitivity, accuracy and precision; (b) investigations to mechanistically understand the environmental influences of time, temperature, soil moisture, soil organic carbon content, and structure/function of the microbial community on agrochemical loss and bioavailability; and (c) investigation of sublethal biological effects of low-level chronic exposure.

Analytical Techniques. Immunoassay methods offer a number of advantages in food and environmental analyses, including reduced time of analysis, low limits of detection, high throughput of samples, cost-effective detection, and adaptability to field uses (Tadeo, 2008). University of Hawaii scientists have developed immunoassay methods for a number of pesticides (Gao et al., 2006; Kim et al., 2004, 2006, 2007; Zhao et al., 2006c; Moon et al., 2007; Xu et al., 2007 a,b), antibiotics and animal and plant growth regulators (Shelver et al., 2005a,c; Deng et al., 2008; Sheng et al., 2009a,b), plant natural products (Tan et al., 2008; Zhao et al., 2006a,b; He et al., 2009), and other environmental pollutants (Parrotta et al., 2005; Pelleguer et al., 2005; Shelver et al., 2005b). These assays have been applied for food analysis (Xu et al. , 2007c; Shelver et al. , 2008; Ma et al. , 2009;), pest control and management (Xu et al., 2006, 2009a), fate studies (Rui et al., 2005) and marine pollution (Xu et al., 2009b).

Proteomics not only characterizes the final gene products in a biological system but also provides detailed information about protein abundances, stabilities, turnover rates, functions, structures, post-translational modifications, and protein-protein interactions. Large-scale, high-throughput omics technologies can comprehensively reveal complex protein networks in a biological system (Hendrickson et al., 2008). Among various protein analytical techniques, mass spectrometry (MS) has emerged as the primary method (Cravatt et al., 2007; Siuti and Kelleher, 2007). Proteomic and metabolomic approaches are relatively new in the field of ecotoxicology. A review of proteomic research in general toxicology (Wetmore and Merrick, 2004) identified only three studies associated with ecotoxicology and a recent search yielded only a few more examples (e.g., Olsson et al., 2004; Kim et al., 2005). Similarly, only a handful of metabolomic studies have been conducted with fish or other aquatic organisms (e.g., Ralston-Hooper et al., 2008). For the full value of these technologies to be realized in ecotoxicology, it is necessary that gene, protein and metabolite expression profiles from sentinel species exposed to common environmental contaminants be determined and mined for relevant biomarkers. Such information will strengthen risk assessments utilizing this comprehensive response technique by reducing the uncertainty commonly associated with biomarker data. Scientists at Purdue University have developed techniques that are ready to be applied for testing a wide range of contaminants.

Previous research on endocrine disrupting compounds (EDCs) in the environment has primarily focused on the exposure of organisms to aquatic sources of EDCs (Payne et al., 2000; Silva et al., 2002; Thorpe et al., 2006; Markman et al., 2007). Methods to quantify exposure in aquatic organisms have been established (Payne et al., 2000; Thorpe et al., 2006), but research concerning the exposure of soil dwelling organisms to EDCs in the soil or sediment is lacking. In addition, most of the research on EDCs in soil has focused on total concentration in soil (Petrovic et al., 2002). However, EDCs adsorb differently to different soils, so the bioavailability of EDCs and risks associated with exposure of organisms to these compounds depends on the properties of the EDCs, properties of the soil, and concentration of EDCs in soil (Duong et al., 2007). Solid-phase microextraction (SPME) was recently used to determine bioavailability of PAHs to earthworms in soil (Jonker et al., 2007). Use of SPME is less expensive and time consuming than the typical in vivo earthworm model. Application of this methodology to EDCs would be an important step forward.

Agrochemical Distribution and Fate as Affected by Transport and Partitioning. The wide use of pesticides in agricultural and urban areas has resulted in their frequent detection in surface water (Thurman et al., 1992; Goolsby and Battaglin, 1993; Meyer and Thurman, 1996; Larson et al., 1997; Clarc and Goolsby, 1999), groundwater (Hallberg, 1989; Barbash and Resek, 1996; Meyer and Thurman, 1996), aquatic biota and sediment (Nowell et al., 1999), and the atmosphere (Majewski and Capel, 1995). In the U. S., at least 143 pesticides and 21 transformation products, representing every major chemical class, have been detected in environmental samples (Konda and Pasztor, 2001), which invokes concern for both environmental and human health issues. Understanding of the major factors influencing agrochemical transport, persistence, and bioavailability in a variety of environments including agricultural fields, turf, and atmospheric and aquatic systems will also allow better management of agrochemicals.

The inflow of some pesticides from Eurasia to the Western U. S. via trans-Pacific atmospheric transport has been identified and documented (Primbs et al., 2008; Genualdi et al., 2009). However, our current understanding of the magnitude of the inflow of pesticides to the U. S. through trans-Pacific transport of Eurasian emissions is very limited. Hageman et al. (2006) estimated the relative contribution of regional (within 150 km radius) and long-range (> 150 km radius) atmospheric transport on dieldrin, alpha-HCH, chlordane, and HCB concentrations in annual snow pack collected from remote high elevation sites in seven Western U. S. national parks. These results estimate that 100% of the concentrations measured in the Alaskan parks were due to long-range transport, while 30 to 70% of the concentrations of these POPs measured in the most westernly continental U. S. park (Mount Rainier National Park) were due to long-range transport (including trans-Pacific transport) (Hageman et al., 2006).

Atmospheric transport over a short or intermediate range may also play an important role in the input of pesticides in sensitive ecosystems. For example, Florida has over 40,000 farms totaling 10 million acres and in 2005, the state ranked first in U. S. sales for snap beans, fresh market tomatoes, cucumbers for pickles and fresh market, bell peppers, squash, watermelon, oranges, grapefruit, tangerines, and sugarcane, and second for sweet corn, strawberries, and greenhouse and nursery crops. Much of this production occurs in South Florida where three National Parks (Everglades, Big Cypress, and Biscayne) are all on the top ten most endangered public lands. Significant concerns exist over the potential risks from atmospheric deposition of pesticides to the Everglades National Park from adjacent agricultural production areas.

The use and disposal of natural and synthetic compounds that offer improvements in agriculture, medical treatment, personal care and residential conveniences may result in the contamination of surface waters. These compounds include antibiotics, hormones and pharmaceuticals used for treating humans and domesticated animals; pesticides used for plant and animal protection; and additives to consumer and personal care products (Kolpin et al., 2002; Lee et al., 2004, 2008). In a nationwide survey of 139 rivers in 30 states, Kolpin et al. (2002) reported the occurrence of pharmaceuticals, hormones or other organic wastewater contaminants in 80% of the streams sampled. In order to improve surface water quality and reduce ecological impacts of impaired surface waters, we need to first identify the sources of contaminants. Research is needed to develop tools that will identify contaminant sources so that source reduction and treatment strategies can be designed to help mitigate surface waters.

Soil erosion induces large variation in soil properties with landscape position, resulting in spatially variable pesticide sorption and degradation rates. Herbicide sorption coefficients in surface soil tend to be highest in depressional areas and lowest in upper slope positions (Novak et al., 1997; Liu et al., 2002; Gaultier et al., 2006). Pesticide degradation rates are also spatially variable in both surface soil and subsurface soil (Liu et al., 2002; Charnay et al., 2005; Gaultier et al., 2007). Estimates of pesticide sorption and degradation determined under static conditions in the laboratory may not be relevant under the dynamic field conditions. A recent field dissipation study did not detect differences in transport of bromide (a tracer of water movement) or the herbicide S-metolachlor in an eroded field despite a large variation in soil properties (Papiernik et al., 2009a,b). Additional research is required to discern the relative importance of interacting soil processes in determining the fate and transport of herbicides in spatially variable landscapes.

Over 40 million acres of U. S. land are covered by tended lawn (Milesi et al., 2005). Maintaining the health and beauty of turf often requires chemical fertilization, thatch treatments and the use of pesticides (Smith and Bridges, 1996). Application rates on lawns and golf courses are considerably higher than the rates for agricultural purposes (Gianessi and Anderson, 1995; Barbash and Resek, 1996). Pesticides that are commonly applied to turf grasses have been found in surface waters of urban areas (Hoffman et al., 2000; Gilliom et al., 2006). Creeping bentrass (Agrostis stolonifers L.), regularly used for golf course turf, is highly susceptible to snow mold fungi (Wang et al., 2005), which is controlled by application of fungicides including chlorothalonil, iprodione and pentachloronitrobenzene. These compounds have been shown to be moderately to highly toxic to aquatic organisms (PAN, 2009; OSU, 2009). In locations with cold climates, the melting of snow and ice produce springtime runoff that may trigger flooding and greatly contributes to stream flow (USGS, 2009). Little is known about the fate of fall-applied turf fungicides with snowmelt as the influence of winter conditions on their persistence and transport is not well studied. Studies are needed for understanding transport of chlorothalonil, iprodione, and pentachloronitrobenzene in snowmelt runoff from turf.

Agrochemical Toxicity. Carbamate and OP insecticides are designed to inhibit acetylcholinesterase (AChE), which hydrolyses the neurotransmitter acetylcholine in nerve and muscle tissues. Inhibition of AChE causes an increase in synaptic acetylcholine to abnormally high levels, resulting in repetitive stimulation of muscarinic and nicotinic receptors in target tissues. Sufficiently high exposure levels produce clinical signs of acute cholinergic poisoning. Long-lasting neurological damage from acute high level exposure to some OPs is well documented (Karczmar, 1984). California and other states require or recommend blood cholinesterase monitoring for pesticide mixer-loaders, applicators, and farm workers, where inhibition of blood AChE activity is used as a biomarker of exposure to OPs. Although a number of field studies of blood cholinesterase levels exist, the test accuracy has not been scrutinized until recently. Researchers at UC Davis, in collaboration with the Washington State Department of Labor and Industry, have been monitoring blood ChE focusing on fruit orchard workers. The goal is to monitor clinical plasma and red blood cell ChE assays to estimate the extent of exposure of the workers to anticholinergic OP pesticides. One report has been published (Wilson et al., 2009a,b) and another is in preparation. The research has amassed one of the largest ChE data bases ever established for farm workers. In addition to monitoring the reliability of the work, its goals include studying the distribution of blood ChEs in a working population and examining the relative sensitivity of serum ChEs compared to red blood cell AChEs under field conditions.

Pesticide handlers, agricultural workers including harvesters, bystanders, and consumers may be exposed to pesticides via various routes. Pesticide exposure may also occur to children and adults following residential use of pesticides including pet products. Researchers at UC Riverside have been undertaking a range of studies to understand human exposure to pesticides. These studies include handler exposure assessment during cyanide fumigation of citrus; assessment of chloropicrin exposure of bystanders during fumigation; relationships between deposition and distribution of pyrethroids applied indoors and human exposure potential; formation of OP biomarkers in produce and the implication for human exposure assessment; evaluation of the persistence of OP biomarkers in leaves and fruits of strawberries; residential exposure following use of total release from pyrethroid foggers; and development of a new procedure for analysis of a urine biomarker for DDT exposure.

Most toxicity studies using whole organisms generally focus on acute (lethal) toxicities. The impact of non-lethal, low-dose agrochemical exposure on non-target organisms has not been studied extensively. Acute sub-lethal exposures can impact an organism's ability to survive in the wild by causing a loss of energy, disorientation or loss of ability to navigate. With the understanding that compromised flying efficiency and migratory orientation may lead to negative effects on migratory bird species, W-2045 researchers in Nevada have chosen homing pigeons (Columba livia) as the test species (Wiltschko and Wiltschko 2003). Recent research has shown that migratory ability in homing pigeons is compromised after exposure to cholinesterase-inhibiting pesticides (Brasel et al. 2007; Moye, 2008) and chemicals found in mining waste (i. e., arsenic and cyanide) (Brasel, 2005; Brasel et al., 2006).

Health risk assessments of chemicals have been traditionally restricted to evaluating the potential risk of a single compound through a single route of exposure (National Research Council 1983). In the last 15 years, however, a great deal of attention has focused on biological effects of chemical mixtures and the endocrine-disrupting nature of various pesticides. Many recent studies demonstrated that certain herbicides could either synergistically or antagonistically affect the toxicity of certain OPs in the aquatic midge (Chironomus tentans) (Belden and Lydy, 2000; Anderson and Lydy, 2001; Jin-Clark et al., 2002, 2008; Anderson and Zhu, 2004; Anderson et al., 2008; Li et al., 2009). Increased toxicity of certain OPs in binary combinations with atrazine correlated to the increased AChE inhibition and increased cytochrome P450 activity (Anderson and Zhu, 2004; Rakotondravelo et al., 2006). W-2045 researchers in Kansas will continue this line of research by developing a cDNA microarray based on the expressed sequence tag data, profiling the gene expression responses in midges exposed to pesticides, and elucidating molecular mechanisms leading to synergistic or antagonistic effects of pesticide mixtures in aquatic midges. Results from this study are expected to provide insights into potential adverse effects of these pesticides at the molecular level, individually and as mixtures, on non-target organisms in aquatic environments.

Pesticide use in Oregon watersheds, particularly those that provide salmon habitat, is of increasing concern. Monitoring studies in Willamette Basing watersheds (Rinella and Janet, 1998; USGS, 2008) suggest that pesticides in surface water may pose a risk to aquatic life fitness and survival, including 26 Evolutionarily Significant Units (ESU) of Pacific salmonids listed as threatened or endangered under the Endangered Species Act (ESA). As required by the ESA as a part of the consultation process, the National Marine Fisheries Service (NMFS) has completed Biological Opinions (NMFS 2008, 2009) for 6 of the 37 pesticide active ingredients that U. S. Environmental Protections Agency (EPA) has determined "may affect" the 26 Pacific salmonid ESUs. In developing the Biological Opinions, NMFS has raised concerns about the paucity of information on pesticide use practices and monitoring data, particularly at the watershed scale. Researchers at Oregon State University will employ both monitoring and modeling methodologies that will allow a more robust evaluation of potential impacts of pesticide use practices on aquatic life including salmon ESUs.

Environmental Transformation Processes and Remediation Technologies. Effective and economical technologies are needed to clean up soil and water contaminated by agrochemicals. Researchers at Cornell (New York) have developed a specialized Fenton system, anodic Fenton treatment (AFT), to study the degradation of ETU, trifluralin and atrazine (Saltmiras and Lemley, 2000, 2001, 2002). A significant improvement to the AFT method was the development of the membrane AFT system (Wang and Lemley, 2002) that uses a semi-permeable membrane to separate the two half-cells. The Cornell group made another significant advance by developing a kinetic model that describes this delivery-controlled AFT (Wang and Lemley, 2001). Membrane AFT was applied to the study of carbofuran and mixtures of six carbamates, and the results were well explained by the kinetic model (Wang and Lemley, 2003a,b). In other work, the Cornell group modified the AFT kinetic model for application to triazines/triazones (Wang and Lemley, 2004), using metribuzin as the primary model compound. A framework was developed for understanding the kinetics of the AFT under flow conditions, an important aspect of future applications (Kong and Lemley, 2006; Zhang and Lemley, 2006, 2007). To further understand the application of this method to soils and soil slurries, several studies were performed on humic acid models (Wang and Lemley, 2006), an actual soil slurry (Kong and Lemley, 2006) and a model soil composed of clay and humic acid (Ye and Lemley, 2009a). More specific studies on the effect of the interaction of pesticides with clays on AFT degradation were done by Ye and Lemley (2008, 2009b). Recent work has shown that a variety of Fenton approaches with continuous delivery of the iron reagent can successfully degrade candidate pesticides (Zeng and Lemley, 2009).

Sunlight photolysis of chemicals on soils, particularly pesticides, has been examined in previous W-1045 projects (Hebert and Miller, 1990; Miller and Donaldson, 1993). These studies demonstrated that transformations on soils are common and are a significant loss mechanism for a variety of agrochemicals. In the last decade, concerns have arisen over the observation of perchlorate in groundwater and soils distant from any industrial source (Christen, 2003). The low amount of perchlorate in fertilizers (Susarla et al., 1999) is likely only a partial source. Members of the W-1045 project in Nevada are presently investigating whether perchlorate can be formed through photooxidation of chloride on soil surfaces. Preliminary evidence suggests that both semiconductor surfaces (e. g., titanium dioxide) (Serpone et al., 1994) and nitrate (Wallvoord et al., 2003) may be involved in photooxidation of chloride, and further investigation will examine this hypothesis.


Please see the attached "Related, Current and Previous Work" document for complete text.

Objectives

1. Identify, develop, and/or validate trace residue analytical methods, immunological procedures, and biomarkers of chemical exposure and effects.
   
2. Characterize abiotic and biotic reaction mechanisms, transformation rates, and fate of chemicals in agricultural and natural ecosystems.
   
3. Determine adverse impacts from agrochemical exposure to cells, organisms, and ecosystems.
   
4. Develop technologies that mitigate adverse human and environmental impacts.
   

Methods

Objective 1: Identify, develop, and/or validate trace residue analytical methods, immunological procedures, and biomarkers of exposure and effects. To characterize and quantify agrochemical exposure and effects to cells, organisms, and ecosystems, appropriate biomakers need to be elucidated and characterized. New sampling and analytical methods need to be examined and optimized with respect to environmental and biological matrices. Research will be conducted at Univ. of Hawaii, Mississippi State University, Cornell University, and UC Riverside to address these needs. Researchers at the Univ. of Hawaii will advance their development of proteomics methodologies, including extending the dynamic range to cover low- and high-abundant proteins and performing efficient protein quantitation and data mining. Purified palm peroxidases will be used as a model system to study post-translational modifications relevant to the novel catalytic and stability properties. Proteomic methods will be developed to study the structure and function of palm peroxidases (Syka et al., 2004; Domon and Aebersold, 2006; Han et al., 2006; Chi et al., 2007). Different MS techniques will be used, including matrix assisted laser desorption/ionization-time of flight/time of flight mass spectrometry (MALDI-TOF/TOF-TOF MS), two dimensional LC nano-electrospray ion trap mass spectrometer (2D LC-ITMS) particularly in electron transfer dissociation (ETD) and electrospray ionization (ESI) modes, and LC-quadrupole/time-of-flight mass spectrometry (LC-Q/TOF MS). Researchers at Cornell (New York) will apply solid-phase microextraction (SPME) techniques to analysis of xenoestrogens in soil media. SPME will be compared with an in vivo method for quantifying exposure. Nematodes such as C. elegans and P. redivivus will be used for an in vivo model. Dose-response curves will be created that relate the dose of the compound in soil to the concentration measured in the SPME fibers and nematodes, and models will be created for dose-response curves. Analysis will be made to determine whether SPME, followed by an in vitro measurement of the estrogenic activity contained in the SPME tubes can predict estrogenic activity as effectively as in vivo screening. Researchers at Mississippi State Univ. will develop multi-residue methods to extract and analyze pesticides and their degradation products simultaneously. Emphasis will be given to the development of methods for sediment, water as well as plant and animal tissue analysis that require minimal sample preparation and no pre-concentration. Simple, rapid, and high throughput methods will be developed for identification and quanititation using HPLC, LC-MS, and/or GC-MS. LC-MS methods will be developed for some new lawn care chemicals (e. g., imidacloprid). A rapid multi-residue method will be developed for the analysis of bed sediment for the herbicides simazine, atrazine, pendamethalin, oxadiazon; the insecticides malathion, diazinon, carbaryl, chlopyrifos and its degradation product trichloropyridinol; and the fungicide chlorthalonil and its principal degradation product hydroxy-chlorthalonil. Such methods will also be developed for fungicides and herbicides most commonly used on crops in Mississippi in support of spray drift investigations and enforcement action. Researchers at UC Riverside will continue to develop and evaluate analytical methods for measuring bioavailable concentrations of pesticides in sediment-water and soil-water systems. Many current-use pesticides are highly hydrophobic and they are preferentially sorbed to sediment or soil particles as well as dissolved organic matter. Most methods measure the total chemical concentration, which may have a poor relationship with the effective concentration causing the toxic effect. UC Riverside researchers will develop and evaluate biomimetic methods such as SPME, and use these methods to understand processes and factors governing the bioavailability of hydrophobic pesticides in sediments or soils. Objective 2: Characterize abiotic and biotic reaction mechanisms, transformation rates, and fate of chemicals in agricultural and natural ecosystems. This research will encompass investigations of agrochemical transformations (mechanisms and rates) and fate in the environment. The research will be applied to agrochemical efficacy, the potential to contaminate air, groundwater and surface water, and chemical and biological remediation strategies. Research will be conducted at Cornell University, the Universities of California, Florida, Hawaii, and Nevada; Mississippi, Montana, and Oregon State Universities; and USDA-ARS locations at St. Paul and Morris, MN, and Beltsville, MD. The Cornell (New York) group will use the anodic Fenton system and other catalytic advanced oxidation methods related to the Fenton reaction to study degradation of slurries and lab-prepared wastewater containing individual pesticides and their mixtures, and pesticide formulation solutions. Investigation of heterogeneous catalysis involving magnetite and other iron containing minerals and clays containing manganese will be carried out. Application of cathodic Fenton as a continuous delivery for hydrogen peroxide reagent will be studied. Concentration of pesticides in different solutions/wastewater at different treatment times will be analyzed using HPLC and LC-MS. Degradation kinetics of pesticides in different solutions/wastewater will be studied and data will be fitted to kinetic models to derive kinetic parameter(s). Degradation mechanisms will be elucidated. Exposure to toxic chemicals triggers a cascade of cellular responses that allow bacteria to defend, detoxify, and adapt to a particular environment or stressor. Univ. of Hawaii researchers will apply MS for proteomic analyses to elucidate adaptation mechanisms for bacterial response to pesticides as well as mechanisms of degradation of pesticides (Lee et al., 2006, 2007, 2009). Genomic and metabolomic techniques will be used to aid the proteomic studies (Hou et al., 2004; Awaya et al., 2008; Tittabutr et al., 2008). Researchers at University of Florida will investigate the use of white rot fungi to degrade DDT and its derivatives (DDx) in contaminated soils as a mean for bioremediation. The fungi will be grown on corncob grits, and enzymes will be rinsed off and used for transforming DDx. Different microcosms will be used for this study. Molecular methods will be used to characterize the white rot fungi. During the microcosm study, levels of various enzymes, including peroxidase, and lactase, will be monitored, and the dissipation of DDx will be quantified using standard EPA methods. The efficiency of removal of DDx, and the limiting factors, will be identified and the knowledge will be used for developing remediation practices that may be used at a realistic scale. USDA-ARS researchers in Morris, MN, will evaluate the relative importance of soil properties that affect pesticide sorption and degradation, soil and topographic effects on soil water movement, timing and intensity of rainfall, and other factors in spatially variable landscapes. To investigate these factors, soil cores will be collected in eroded landscapes and sectioned by horizon. The sorption and transformation of S-metolachlor or other commonly used herbicides will be determined at field-relevant application rates. An in-house rainfall simulator will be used to understand the relative impact of soil properties on pesticide runoff under different rainfall scenarios. Using the results of field and laboratory assessments and simulation models, an indication of the relative importance of different soil processes on overall solute transport in spatially variable landforms will be possible. USDA-ARS researchers in Beltsville, MD, will use model simulations to examine the environmental conditions, agronomic practices, and chemical drivers that enhance pesticide volatilization in Florida. A separate transport model will be used to predict the potential for pesticide deposition to the National Parks and surrounding areas. The pesticides to be considered include endosulfan and chlorpyrifos. An adapted version of the Community Multiscale Air Quality modeling systems (CMAQ) will be used to simulate pesticide atmospheric transport and wet and dry atmospheric deposition processes. It will also provide temporal trends in air concentration and deposition flux estimates to the South Florida region. USDA-ARS researchers in St. Paul, MN, will collect surface water samples from 9 rivers of the Zumbro River watershed (southern Minnesota) during the spring, summer, and fall over two years. These 9 rivers have land uses differing in percent and type of agriculture and percent of urban sewered or suburban septic-systems. All relevant land uses will be sampled upstream of the wastewater treatment plant. Water samples will be analyzed for about 30 selected target compounds associated with animal agriculture, row crop agriculture, residential/urban pest control, human pharmaceutical use, personal care product use and wastewater discharge. These compounds will be analyzed using GC/MS or LC/MS-MS. Recorded land uses and measured surface water contaminants of each river will be compared to differentiate agricultural sources from non-agricultural sources, and to determine the comparative load of contaminants to surface water, which can in turn be used to help develop strategies to reduce their occurrence. In a separate study, USDA-ARS scientists in St. Paul, MN, will study runoff of snow-mold fungicides (chlorothalonil, iprodione, PCNB) from fairway turf plots. Natural rainfall runoff, occuring before snowfall, and snowmelt runoff will be collected along with weather data, soil temperatures and frost depths from October through April. Flow meters and automated samplers will record runoff volumes and flow rates and collect runoff samples. Fungicides will be analyzed by GC/MS or LC/MS-MS. The mass of fungicide transported from the fairway turf with snow-melt runoff will be calculated from recorded runoff volumes and measured fungicide concentrations. Researchers at Oregon State University developed sensitive and accurate analytical methods to measure a wide range of current use and historic use pesticides in all components of remote ecosystems; including air, snow, lake water, sediment and biota (Usenko et al., 2005; Usenko et al., 2007; Ackerman et al., Primbs et al., 2008; Stanley et al., 2009). These methods will be used to measure pesticide residues in fish collected from remote mountain ecosystems in national parks to determine if there is a correlation between pesticide body burden and intersex in adult fish (Ackerman et al., 2008; Schwindt et al., 2009). Researchers at Oregon State University will collaborate with personnel at the Oregon Poison Control Center to access their epidemiological data on human pesticide poisoning incidents. Data will be extracted to identify the geographic location of the incident, the location where the exposure occurred, the medical outcome, the reason for exposure, age, and the active ingredient in the pesticide(s). Pesticide exposure incidents containing data on the location of exposure will be analyzed using SaTScanTM Version 6.0 (Kulldorff, 2005) to generate a spatial and temporal scan statistics to determine incidents involving serious medical outcomes and occupational exposure incidents, and to assess whether incidents are clustered in different geographic counties. Results of these analyses will be shared with relevant stakeholders. These interactions will provide opportunities to develop preventive interventions. The effectiveness of interventions in reducing the risks will be further studied prospectively using Poison Control Center data, GIS, and spatial scan statistics. Laboratory and greenhouse studies will be conducted by Montana State University researchers to investigate factors influencing selectivity and resistance of herbicides at the whole plant or cellular level in crops, agronomic weeds, and exotic, invasive weeds. Experiments will be designed to measure the absorption, translocation, metabolism, and photodegradation of herbicides. Radiolabelled herbicides will be used to follow their movement and degradation at the whole plant and cellular levels. Herbicide degradation products will be isolated and elucidated using chromatography techniques. Herbicide translocation as it relates to photosynthate redistribution will also be characterized. Objective 3: Determine adverse impacts from agrochemical exposure to cells, organisms, and ecosystems. This research will investigate the environmental impact of agrochemical exposure to non-target organisms from the cellular level to the population level. Research will be conducted at the Universities of Nevada and California (Davis and Riverside), Oregon State University, and Purdue University. Researchers at Purdue University (Indiana) will apply genomic, proteomic, and metabolomic tools to better understand the mechanisms of toxicity as well as develop biomarkers of exposure for a range of environmental contaminants. The test models will include a fish (fathead minnow, Pimephales promelas) and invertebrates (Hyalella azteca and Daphnia magna). For the microarrays, the researchers will utilize a recently developed array that is targeted towards early life stages of fathead minnow (Kane et al., 2008), as well as a microarray for H. azteca recently developed in collaboration with scientists from Indiana University and that interrogates over 500 K reads. Proteomic analyzes will be conducted using two-dimensional gel electrophoresis coupled with MALDI TOF/TOF mass spectrometry as described in Sanchez et al. (2009). For the metabolomic analyses, the researchers will use a combination of GC-MS and LC-MS (Ralston-Hooper et al., 2008). Researchers at Kansas State University will use aquatic midges to understand the toxicities of pesticides individually and in binary combinations. For microarray analysis, the researchers will design and produce several Agilent high-resolution 8x15K multi-pack expression microarrays for single-color detection using the C. tentans EST library. Agilent's probe design algorithms will be used to computationally design 60-mer oligonucleotide probes from each of the 2,912 unique ESTs. Total RNA from each sample will be used to synthesize cDNA that will then be transcribed into cRNA and labeled with fluorophore such as phycoerythrin, cyanine 3 (Cy3) or cyanine 5 (Cy5). After hybridization, arrays will be washed and scanned using Axon GenePix 4000B. The signal intensity of each gene will be globally normalized according to Yang et al. (2002). The gene expression data will be analyzed by using GeneSpring software (Silicon Genetics). Finally, both up- and down regulated genes from each comparison that appear to be relevant to pesticide metabolism (e.g., P450) will be verified and quantified by quantitative PCR. Researchers at UC Davis will collaborate with Washington State agencies to collect and assay blood from orchard workers from several sites using automated equipment (Olympus), and a bovine AChE standard. The selected groups of orchard workers will be exposed to pesticides during their activities, their blood samples collected and analyzed. Their urine samples will be collected before and after exposure. The blood ChEs will be determined colorimetrically and the OP metabolites by GC/MS. The efficacy of pyridostigmine bromide (PB) in protecting bovine and human red blood cell AChE from the active (oxon) forms of pesticides such as diazinon, chlorpyrifos and the OP diisopropyl fluorophospate (DFP) and the carbamate serine will be studied using colorimetric assays. Researchers at UC Riverside will carry out human object studies using protocols approved by the Institutional Review Board, UC Riverside, and California EPA, and Department of Pesticide Regulation. Volunteers will be provided detailed descriptions of expectations and instructions. Urine biomonitoring will utilize convenience spot samples or complete 24 h collections. Biomarkers of OPs, pyrethrin and pyrethroids, N-methyl carbamates, borates, 2, 4-D/triclopyr, and fipronil will be studied in a variety of use scenarios. Biomarkers of malathion, danitol, and captan will be studied in strawberry foliage, berries, and on passive dosimeters as part of continuing studies of preformed biomarkers in exposure assessment. Researchers at UN Reno will study the effect of lead and mercury on the migratory and reproductive abilities of exposed avian species, and if exposure to the parents affects the learning abilities of the offspring. Some of the lead and mercury residues are originated from contamination by mercury or lead based agrochemicals used in the past. Researchers will use homing pigeon as a model to understand the effect of low-dose mercury or lead exposure on migratory bird flight, reproduction, and offspring exposure. They will consider time-flight studies using homing pigeons, analyze mercury and lead in bird tissues, observe changes in reproduction using exposed birds, and characterize effects on behaviors such as training and learning abilities of the affected offspring. Oregon State University researchers will employ both monitoring and modeling methodologies to evaluate potential impacts of pesticide use practices on aquatic life including salmon ESUs in the Pudding watershed within the Willamette Basin, Oregon. Researchers will employ a passive sampling device (PSD) (Anderson et al., 2008) to continuously monitor in-stream pesticide concentrations. In addition, a GIS-based watershed scale pesticide environmental fate model (Soil and Water Assessment Tool, or SWAT) will be used to evaluate the relationship between land use, pesticide use practices, climate, and potential for pesticide surface water loading at the watershed scale. SWAT input data, model parameters and/or model processes can be changed in order to simulate changes in land cover/land use, changes in pest management or the implementation of beneficial management practices. This approach will be used to identify IPM and other beneficial management practices that have the potential to reduce pesticide loading. In addition, SWAT simulations will be used to identify areas within the watershed where the implementation of mitigation measures could have the greatest impact on the reduction of chemical loading. Objective 4: Develop technologies that mitigate adverse human and environmental impacts. Drawing from W-2045's multidisciplinary collaborations and expertise, economically viable technologies and management strategies will be developed to prevent and/or mitigate adverse agrochemical impacts on human and environmental health. Researchers and extension specialists at Mississippi and Washington State Universities, UC Riverside, and ARS laboratories in Beltsville (MD), and St. Paul (MN) will work towards this objective while assuring the technological transferability to stakeholders (including state safety and health agencies, chemical manufacturers, growers, extension specialists, and others). Washington State University researchers will continue to work with the grower community and regulatory agencies to estimate fumigation emission rates from putative reduced-emission practices. For upcoming studies, field fumigant emission rates and total cumulative losses will be estimated using a steady-state Gaussian plume algorithm and back calculation approach from near-field MITC receptor locations. This least-squares technique is consistent with practices employed by state and federal regulatory agencies for establishing risks to inhalation exposure (Johnson et al., 1999; Ross et al., 1999). In 2009-2011 the researchers will also examine the rate and efficiency of conversion of metam sodium to MITC in laboratory soil columns to understand surface volatilization of MITC at temperatures and moisture conditions typical of eastern Washington application practices. USDA-ARS researchers in St. Paul, MN, will conduct studies evaluating the influence of tillage practices (conventional, conservation, strip and no-till) and drainage water management (conventional tile drains, controlled tile drains) on the dissipation and mobility of chloroacetanilide herbicides (metolachlor and acetochlor) and their degradation products in row crop (corn, soybean) soils. Replicate soil cores and water samples (lysimeter or tile drain water) will be collected throughout the growing season. Pesticide distribution in soil as a function of depth will be determined. The dissipation and mobility of the applied herbicide and the formation and transport of the degradation products will be compared to determine the best strategy for maintaining weed control while protecting ground and surface waters. Turf management typically involves very intensive agrochemical use patterns. Researchers at Mississippi State Univ. will collaborate with USDA-ARS scientists in St. Paul, MN to identify management practices that minimize agrochemical losses from turf by runoff following rainfall, irrigation, and snow melt. Measurements of pesticide runoff will be incorporated with key environmental parameters to calibrate computer exposure model scenarios. The investigators will test the predictive ability of the Pesticide Root Zone Model (PRZM 3) linked with EXAMS 3.12 to simulate runoff and estimate chemical loading to aquatic systems. The validation of this model has immediate regional and national utility for mitigating surface runoff at high loading source locations. Nonpoint source pollution due to surface runoff is the main course for water quality impairment of surface streams in the U.S. The impairment may be caused by contamination by pesticides or nutrients. Irrigation and rain induced runoff of insecticides can lead to toxicity to sensitive aquatic invertebrates in both agricultural and urban watersheds. Researchers at UC Riverside will continue to work with stakeholders including regulators, growers, extension advisors, the agrochemical industry, and pesticide applicators to develop, evaluate and promote the use of mitigation practices such as constructed wetlands, vegetative buffers, and improved application techniques. Field studies will be carried out to test these mitigation practices, and results from these and other studies will be extended to the various stakeholders through outreach seminars, newsletters and websites.

Measurement of Progress and Results

Outputs

• The results of our research will be disseminated to the scientific community through publications in refereed journals, presentations at national and international meetings, and departmental seminars. Results will be presented to various lay stakeholders as described in Outreach Plan below.
• Rapid and sensitive analytical methods for pesticides and other environmental pollutants including pyrethroids, neonicotinoid insecticides, adrenergic agonists, will be developed. These methods will allow for high-throughput screening of water and other environmental samples, and will increase our capability for screening environmental matrices contaminated with pesticides. Similar methods will be used in the analysis of urine in residential and occupational exposure assessments. A standard assay for cholinesterase levels as an indication of exposure to cholinesterase inhibitors (including nerve agents, pesticides, etc.) will be recommended, which will be valuable in protecting armed forces, agricultural workers, and others exposed to these chemicals from debilitating effects.
• We will be in direct communication with agrochemical manufacturers to offer suggestions for improving product efficacy and developing label recommendations and restrictions to protect human and environmental health. Results will be also available to federal and state regulatory agencies, which may use this information in future decisions regarding agrochemical registration, risks/benefits, tolerances, and restrictions. Results on the trans-Pacific and regional atmospheric transport of pesticides and their deposition to sensitive high elevation ecosystems will be used to influence global regulatory strategies on the use of pesticides in developing countries and to aid the U. S. National Park Service in managing Park exposure to pesticides due to long-range atmospheric transport.
• Products developed in this project include: a pilot flow-through AFT system for degradation of agrochemicals; bioremediation technologies; invasive weed management strategies; management practices for mitigating pesticide runoff and leaching; and new fumigant application technologies for improved dispersion in the root zone and reduced atmospheric emissions.

Outcomes or Projected Impacts

• Current technologies and the cost and availability of labor dictate the use of pesticides for managing weeds, insects, nematodes, and diseases in most cropping systems. To increase crop and rangeland production efficiency, agriculturalists must reduce the impact of crop losses due to pests using cultural, chemical, and biological pest control strategies. New exotic weeds, new genotypes exhibiting environmental tolerance or herbicide resistance, or alternate species can invade open habitats very rapidly. Understanding the mechanisms involved will improve our ability to better predict and integrate current and potential pest management strategies, providing environmentally sound and cost effective approaches to pest management. These approaches will lead to reduced application of pesticides in the long term.
• The results of these studies will provide insights into the effects of low-dose exposure to various agrochemicals on non-target species. State and Federal regulatory agencies may use this information in decisions regarding the registration and use of these and other agrochemicals based on a similar mechanism of toxicity. There is a critical need to develop animal models to indicate the impact of agrochemicals, including endocrine-disrupting compounds, on non-target species. The development of the migratory bird and fish models into research and regulatory tools for assessing the impact of an agrochemical on non-target species will be very valuable in protecting fish and wildlife. These models will also be useful to the agrochemical industry in evaluating the toxicity of existing and proposed products.
• The off-site transport of agrochemicals is both an agronomic and environmental concern reducing efficacy in the area of application while increasing contamination to non-target surrounding ecosystems. Results of this research will provide information on the fate of nutrients and pesticides in the soil/water/air and sediment/water system, and will identify environmental factors influencing agrochemical fate. This research will provide information to manufacturers on the efficacy and environmental fate of their products. The data gained from this research can be used to develop best management practices to reduce the movement of these chemicals to non-target ecosystems. It will also allow development of computer-simulated pesticide exposure scenarios using established regulatory models to estimate the impact of new and existing chemistries on environmental systems under various management practices. In addition, the multi-state data will be valuable to regulatory agencies in establishing scientifically based criteria for the registration and use of pesticides and fertilizers on crops and turf.
• The 2002 USDA Census of Agriculture estimated that there were over 3 million hired farm workers in the U.S. Of this total, a large fraction is employed in CA (0. 53 M) and WA (0. 26 M), where they are likely exposed to a variety of pesticides. In addition, hundreds of thousands of military personnel risk exposure to organophosphates and carbamates. Our research will include environmental and biological monitoring of a variety of work tasks of pesticide handlers and harvesters of treated crops. These data will serve to clarify the extent of risk resulting from exposure and provide exposure data for more objective establishment of field entry intervals and the effectiveness of personal protective equipment. Collaborative work with the a number of state and federal agencies aims to set the stage for a national standard (and appropriate conversions) for the monitoring of blood cholinesterase levels, providing early warnings of dangerous exposures.

Milestones

(0):ase see the attached "Milestones" document for complete text.

Projected Participation

View Appendix E: Participation

Outreach Plan

The results obtained by the W-1045 scientists will be disseminated to a wide range of stakeholders including scientists, governmental agencies, growers, farm advisors, agrochemical manufacturers, professional pesticide applicators, and the lay public. A variety of methods will be employed to disseminate this information, depending upon the audience. The research results will be distributed to the scientific community through publications in refereed journals and presentations at local (e.g., departmental), regional, national, and international meetings. Results will be presented to stakeholders through trade magazine publications; demonstration tours; outreach presentations and materials; learning centers; technical reports to growers, manufacturers and crop consultants; workshops; online education modules; presentations to state commodity groups; state crop commissions, local watershed and conservation districts, funding organizations etc.; presentations at annual field days; and Certified Crop Advisor proficiency testing modules. Members associated with national development of regulatory policy for pesticides will insure that relevant research findings from W-3045 are known to policy officials to increase the impact of research results.

Organization/Governance

The Technical Committee is composed of the members who represent the participating experiment stations, state extension services, and Agricultural Research Service units, as well as an Administrative Advisor, and a representative of NIFA. Annual meetings of W-2045 members incorporate a critical peer-review process of members' research activities. Prior to an annual meeting, each technical committee member prepares an individual written report of research activities conducted over the prior year. At the annual meeting, each report is assigned to a review team consisting of three other committee members who then provide critical feedback to the investigator on their research activities during the meeting. The officers of the Technical Committee will serve for two years each, and be a chairman and a secretary. The chairman of the technical committee coordinates the collaborative research and the annual technical meeting, with consultation from the administrative advisor. The chairman prepares the agenda, makes report review assignments, presides over the annual meetings and is responsible for preparation of the annual report. The secretary is responsible for recording and distributing the minutes of the technical committee meeting and carrying out duties assigned by the technical committee or administrative advisor. The officers and the immediate past chairman comprise the Executive Committee, which is empowered to act for the Technical Committee between annual meetings.

Literature Cited

Ackerman, L.; Schwindt, A.; Koch, D.; Wilson, G.; Simonich, S.L.Atmospherically deposited PBDEs, pesticides, and PAHs in western U.S. national park fish: Concentrations and consumption guidelines, Environ. Sci. Technol. 2008, 42, 2334-2341.

Anderson, K.A.; Sethajintanin, D.; Sower, G. and L Quarles. 2008. Field trial and modeling uptake rates of in-situ lipid-free polyethylene membrane passive sampler. Environ. Sci. Technol. 42, 4486-4493.

Anderson, T.D.; Jin-Clark, Y.; Begum, K.; Starkey, S.R.; Zhu, K.Y. Gene expression profiling reveals decreased expression of two hemoglobin genes associated with increased consumption of oxygen in Chironomus tentans exposed to atrazine: A possible mechanism for adapting to oxygen deficiency. Aquat. Toxicol. 2008, 86, 148-156.

Anderson, T.D.; Lydy, M.J. Increased toxicity to invertebrates associated with a mixture of atrazine and organophosphate insecticides. Environ. Toxicol. Chem. 2001, 21, 1507-1514.

Anderson, T.D.; Zhu, K.Y. Synergistic and antagonistic effects of atrazine on the toxicity of organophophorodithioate and organophosphorothioate insecticides to Chironomus tentans (Diptera: Chironomidae). Pestic. Biochem. Physiol. 2004, 80, 54-64.

Aspelin, A.L.; Grube, A.H. 1999. Pesticides industry sales and usage: 1996 and 1997 market estimates. U.S. Environmental Protection Agency, Washington DC #733-R-99-001

Awaya, J.D.; Tittabutr, P.; Li, Q.X.; Borthakur, D. Pyruvate carboxylase is involved in metabolism of mimosine by Rhizobium sp. strain TAL1145. Arch. Microbiol. 2008, 190, 409-415.

Barbash, J.E.; Resek, E.A. Pesticides in Groundwater: Distribution, Trends, and Governing Factors. Ann Arbor Press, Chelsea, MI, USA, 1996.


Belden, J.B.; Lydy, M.J. Impact of atrazine on organophosphate insecticide toxicity. Environ. Toxicol. Chem. 2000, 19, 2266-2274.

Brasel, J. M. Developing the homing pigeon (Columba livia) to assess the effects of xenobiotics on avian species. Environmental Sciences Program, University of Nevada-Reno. Doctor of Philosophy: 2005, 111.

Brasel, J.M.; Collier, A.B. et al. Differential toxic effects of carbofuran and diazinon on time of flight in pigeons (Columba livia): Potential for pesticide effects on migration. Toxicol. Applied Pharmacol. 2007, 219: 241-246.

Brasel, J.M.; R.C. Cooper; et al. Effects of environmentally relevant doses of cyanide on flight times in pigeons, Columba livia. Bull. Environ. Contam. Toxicol. 2006, 76, 202-209.

Bryden, P.A.; McKnight, R.H.; Westneat, S.C. Using U.S. Poison Control Center records to identify bystander pesticide exposures: a one-year surveillance of four southeastern states. J. Agric. Saf. Health 2005, 11, 159-166.

Charnay, M.-P.; Tuis, S.; Coquet, Y.; Barriuso, E. Spatial variability in 14C-herbicide degradation in surface and subsurface soils. Pest Manag. Sci. 2005, 61, 845-855.

Chi, A.; Huttenhower, C.; Geer, L.Y.; Coon, J.J.; Syka, J.E.P.; Bai, D.L.; Shabanowitz, J.; Burke, D.J.; Troyanskaya, O.G.; Hunt, D.F. Analysis of phosphorylation sites on proteins from Saccharomyces cerevisiae by electron transfer dissociation (ETD) mass spectrometry. Proc. Natl. Acad. Sci. U.S.A. 2007, 104, 2193-2198.

Christen, K. Perchlorate mystery surfaces in Texas. Environ. Sci. Technol. Nov. 1, 2003, 376A-377A.

Clarc, G.M.; Goolsby, D.A. Occurrence and transport of acetochlor in streams of the Mississippi River Basin. J. Environ. Qual. 1999, 28, 1787-1795.

Cravatt, B. F.; Simon, G. M.; Yates, J. R., III. The biological impact of mass-spectrometry-based proteomics. Nature 2007, 450, 991-1000.

De Guzman, N.P.; Hendley, P.; Gustafson, D.I.; Van Wesenbeeck, I.; Klein, A.J.; Fuhrman, J.D.; Travis, K.; Simmons, N.D.; Teskey, W.E.; Durham, R.B. The acetochlor registration partnership state ground water monitoring program. J. Environ. Qual. 2005, 34, 793-803.

Deng, A.; Tan, W.; He, S.; Liu, W.; Nan, T.; Wang, B.; Li, Q.X. Monoclonal antibody-based enzyme linked immunosorbent assays for analysis of methyl jasmonate in plants. J. Integrative Plant Biology 2008, 50, 1046-1052.

Domon, B.; Aebersold, R. Mass spectrometry and protein analysis. Science 2006, 312, 212-217.

Duong, C.N.; Schlenk, D.; Chang, N. I.; Kim; S.D. The effect of particle size on the bioavailability of estrogenic chemicals from sediments. Chemosphere 2009, 76, 395-401.

Gao, H.; Ling, Y.; Xu, T.; Zhu, W.; Jing, H.; Sheng, W.; Li, Q.X.; Li, J. Development of an enzyme-linked immunosorbent assay for the pyrethroid insecticide cyhalothrin. J. Agric. Food Chem. 2006, 54, 5284-5291.

Gaultier, J.D.; Farenhorst, A. 2,4-D mineralization in soil profiles of a cultivated hummocky landscape in Manitoba, Canada. J. Environ. Sci. Health, Part B. 2007, 42, 255-264.

Gaultier, J.; Farenhorst, A.; Crow, G. Spatial variability of soil properties and 2,4-D sorption in a hummocky field as affected by landscape position and soil depth. Can. J. Soil Sci. 2006, 86, 89-95.

Genualdi, S.; Killin, R.; Woods, J.; Wilson, G.; Schmedding, D.; Massey Simonich, S. Trans-Pacific and Regional U.S. Atmospheric transport of PAHs and pesticides in biomass burning emissions. Environ. Sci. Technol. 2009, 43, 1061-1066.

Gianessi, L.P.; Anderson, J.E. Pesticide Use in U.S. crop production. National Summary Report. Washington, DC : National Center for Food And Agricultural Policy, Washington DC, USA, 1995.

Gibbs, L.A.; Sterling, T.M. Seasonal variation of picloram metabolism in broom and threadleaf snakeweed populations in a common garden. Weed Sci. 2004, 54, 206-212.

Gilliom, R.J.; Barbash, J.E.; Crawford, C.G.; Hamilton, P.A.; Martin, J.D.; Nakagaki, N.; Nowell, L.H.; Scott, J.C.; Stackelberg, P.E.; Thelin, G.P.; Wolock, D.M. Pesticides in the nations streams and ground water 1992-2001. USGS National Water Quality Assessment Program report, 2006.

Goolsby, D.A.; Battaglin, W.A. Occurrence, distribution and transport of agricultural chemicals in surface waters of the Midwestern United States. In Goolsby, D.A.; Boyer, L.L.; Mallard, G.E., eds, Selected Papers on Agricultural Chemicals in Water Resources of the Midcontinental United States. U.S. Geological Survey Open-File Report 93-418, 1993, pp.1-25.

Hageman, K.J.; Simonich, S.L.; Campbell, D.H.; Wilson, G.R.; Landers, D.H. Atmospheric deposition of current-use and historic-use pesticides in snow at national parks in the western United States. Environ. Sci. Technol. 2006, 40, 3174-3180.

Hallberg, G.R. Pesticide pollution of groundwater in the humid United States. Agric. Ecosyst. Environ. 1989, 26, 299 367.

Han, X.; Jin, M.; Breuker, K.; McLafferty, F.W. Extending top-down mass spectrometry to proteins with masses greater than 200 kilodaltons. Science 2006, 314, 109-112.

He, S.-P.; Tan, G.-Y.; Li, G.; Tan, W.-M.; Nan, Wang, B.-M.; Li, Z.-H.; Li, Q.X. Development of a sensitive monoclonal antibody-based enzyme-linked immunosorbent assay for the anti-malaria active ingredient artemisinin in the Chinese herb Artemisia annua L. Anal. Bioanal. Chem. 2009, 393, 1297-1303.

Hebert, V.R.; Miller, G.C. Depth dependence of direct and indirect photolysis on soil surfaces. J. Agric. Food Chem. 1990, 38, 913-918.

Hendrickson, E. L.; Lamont, R. J.; Hackett, M. Tools for interpreting large-scale protein profiling in microbiology. J. Dental Res. 2008, 87, 1004-1015

Hoffman, R.S.; Capel, P.D.; Larson, S.J. Comaprison of pesticides in eight U.S. urban streams. Environ. Toxicol. Chem. 2000, 19, 2249-2258.

Holden, L.R.; Graham, J.A.; Whitmore, R.W.; Alexander, W.J.; Pratt, R.W.; Liddle, S.K.; Piper. L.L. Results of the national alachlor well water survey. Environ. Sci. Technol. 1992, 26, 935-943.

Hou, S.; Saw, J.; Lee, K.S.; Freitas, T.A.; Belisle, C.; Kawarabayasi, Y.; Donachie, S.P.; Galiperin, M.Y.; Koonin, E.V.; Makarova, K.S.; Omelchenko, M.V.; Sorokin, A.; Wolf, Y.I.; Li, Q.X.; Keum, Y.S.; Campbell, S.; Denery, J.; Aizawa, S.-I.; Shibata, S.; Malahoff, A.; Alam, M. 2004. Genome sequence of the deep-sea ³-Proteobacterium Idiomarina Ioihiensis reveals amino acid fermentation as source of carbon and energy. Proc Natl Acad Sci USA. 2004, 101, 18036-18041.

Hughes, A.A.; Bogdan, G.M.; Dart, R.C. Active surveillance of abused and misused prescription opioids using poison center data: a pilot study and descriptive comparison. Clin. Toxicol. 2007, 45, 144-151.

Jin-Clark, Y.; Anderson, T.D.; Zhu, K.Y. Effect of Alachlor and metolachlor on toxicity of chlorpyrifos and major detoxification enzymes in the aquatic midge, Chironomus tentans (Diptera: Chironomidae). Arch. Environ. Contam. Toxicol. 2008, 54, 645652.

Jin-Clark, Y.; Lydy, M.J.; Zhu, K.Y. Effects of atrazine on chlorpyrifos toxicity in Chironomus tentans (Diptera: Chironomidae). Environ. Toxicol. Chem. 2002, 21, 598-603.

Johnson, B.; Barry, T.; Wofford, P. Workbook for Gaussian Modeling Analysis of Air Concentration Measurements. Report EH99-03. 1999, Calif. Depart. Pest. Regul.

Jonker, M.T.O.; van der Heijden, S.A.; Kreitinger, J.P.; Hawthorne, S.B. Predicting PAH bioaccumulation and toxicity in earthworms exposed to manufactured gas plant soils with solid-phase microextraction. Environ. Sci. Technol. 2007, 41, 7472-7478.

Kane, M.D.; Springer, J.A.; Iannotti, N.V.; Gough, E.S.; Johns, S.M.; Schlueter, S.D.; Sepúlveda, M.S. Identification of development and tissue-specific gene expression in the fathead minnow (Pimephales promelas) using computational and DNA microarray methods. J. Fish Biol. 2008, 72, 2341-2353.

Karczmar, A.G. Acute and long lasting actions of organophosphate agents. Fundam. Appl. Toxicol. 1984, 4, S1S17.

Kim, H.-J.; Gee, S.J.; Li, Q.X.; Hammock, B.D. 2007. Non-competitive fluorescent immunoassay for detection of pyrethroid biomarker 3-phenoxybenzoic acid in human urine with KinExATM 3000. In: Rational Environmental Management of Agrochemicals  Risk Assessement, Monitoring, and Remedial Action. Ivan R. Kennedy, Keith R. Solomon, Shirley J. Gee, Angus N. Crossan, Shuo Wang, Francisco Sanchez-Bayo (Editors). ACS Symposium Series 966. Washington DC.

Kim, H.-J.; Shelver, W.L.; Hwang, E.-C.; Xu, T.; Li, Q.X. Automated flow fluorescent immunoassay for part per trillion detection of the neonicotinoid insecticide thiamethoxam. Analytica Chimica Acta 2006, 571, 66-73.

Kim, H.-J.; Shelver, W.L.; Li, Q.X. Monoclonal antibody-based enzyme-linked immunosorbent assay for the insecticide imidacloprid. Anal. Chim. Acta 2004, 509, 111-118.

Kim, Y.K., Yoo, W.I., Lee, S.H., Lee, M.Y. Proteomic analysis of cadmium-induced protein profile alterations from marine alga Nannochloropsis oculata. Ecotoxicology 2005, 14, 589-596.

Kolpin, D.W.; Furlong, E.T.; Meyer, M.T.; Thurman, E.M.; Zaugg, S.D.; Barber, L.B.; Buxton, H.T. Pharmaceuticals, hormones, and other organic wastewater contaminants in U.S. streams, 1999-2000: a national reconnaissance. Environ. Sci. Technol. 2002, 36, 1202-1211.

Konda, L.N.; Pasztor, Z. Environmental distribution of acetochlor, atrazine, chlorpyrfos, and propisochlor under field conditions. J. Agric. Food Chem. 2001, 49, 3859-3863.

Kong, L.; Lemley, A.T. Kinetic modeling of 2,4-D degradation in soil slurry by anodic Fenton treatment. J. Agric. Food Chem. 2006, 54, 3941-3950.

Kulldorff, M. Information Management Services. SaTScanTM v6.0: Software for the spatial and space-time scan statistics, 2005, http://www.satscan.org/.

Larson, S.J.; Capel, P.D.; Majewski, M.S. Pesticides in Surface Waters: Distribution, Trends, and Governing Factors. Vol 3 of series, Pesticides in the Hydrologic System; CRC Press, Boca Raton, FL, 1997.

Lee, K.E.; Barber, L.B.; Furlong, E.T.; Cahill, J.D.; Kolpin, D.W.; Meyer, M.T.; Zauff, S.D. Presence and distribution of organic wastewater compounds in wastewater, surface, ground, and drinking waters, Minnesota, 2000-2002. U.S. Geological Survey Scientific Investigation Report 2004-5138. Reston, Virginia, USA, 2004.

Lee, K.E.; Yaeger, C.S.; Jahns, N.D.; Schoenfuss, H.L. Occurrence of endocrine active compounds and biological responses in the Mississippi River-study design and data, June August 2006. U.S. Geological Survey Data Series 368. Reston, Virginia, USA, 2008.

Lee, S.-E.; Li, Q.X.; Yu, J. Proteomic responses to formic acid on Ralstonia eutropha. Proteomics 2006, 6:4259-4268.

Lee, S.-E.; Li, Q.X.; Yu, J. Diverse protein regulations on PHA formation in Ralstonia eutropha on short chain organic acids. Int. J. Biol. Sci. 2009, 5:215-225.

Lee, S.-E.; Seo, J.S.; Keum, Y.-S.; Lee, K.-J.; Li, Q.X. Fluoranthene metabolism and associated proteins in Mycobacterium sp. JS14. Proteomics 2007, 7,2059-2069.

LePage, J.; Hebert, V. 2007 Near Field Emissions of MITC Following Shank Injection and Chemigation Metam Applications. Analytical Summary Report , 2008. pp 42. (Technical report FEQL-1207B).

LePage, J.; Hebert, V. Optimizing Fumigant Efficacy While Minimizing Off-target Volatile Emissions. Analytical Summary Report. 2007. pp 78. (FEQL 1106).

Li, X.; Zhang, X.; Zhang, J.; Zhang, X.; Starkey, S.R.; Zhu, K.Y. Identification and characterization of eleven glutathione S-transferase genes from the aquatic midge Chironomus tentans (Diptera: Chironomidae). Insect Biochem. Molec. Biol. 2009 (in press).

Littke. M.; LePage. J.; Hebert, V. Estimating Methyl Isothiocyanate emission rates following soil incorporated shank and modified center pivot chemigation metam Sodium applications. Analytical Summary Report, 2009, pp 69. (Technical report FEQL-0808).

Liu, Z.; Clay, S. A.; Clay, D. E. Spatial variability of atrazine and alachlor efficacy and mineralization in an eastern South Dakota field. Weed Sci. 2002, 50, 662-671.

Ma, H.X.; Xu, Y.J.; Li, Q.X.; Wang, X.T.; Li, J.; Xu, T. 2009. Application of enzyme-linked immunosorbent assay for quantitation of the insecticides imidacloprid and thiamethoxam in honey samples. Food Additives and Contaminants: Part A 26, 713-718.

Majewski, M.S.; Capel, P.D. Pesticides in the Atmosphere: Distribution, Trends, and Governing Factors. Vol 1 of series, Pesticides in the Hydrologic System; CRC Press, Boca Raton, FL, 1995.

Markman, S.; Guschina, I.A.; Barnsley, S.; Buchanan, K.L.; Pascoe, D.; Muller, C.T. Endocrine disrupting chemicals accumulate in earthworms exposed to sewage effluent. Chemosphere 2007, 70, 119-125.

Meyer, M.T.; Thurman, E.M. Herbicide Metabolites in Surface Water and Groundwater; ACS Symposium Series 630; American Chemical Society: Washington, DC, 1996.

Milesi, C.; Running, S.W.; Elvidge, C.D.; Dietz, J.B.; Tuttle, B.T.; Nemani, R.R. Mapping and modeling the biogeochemical cycling of turf grasses in the United States. Environ. Manage. 2005, 36, 426-438.

Miller, G.C.; Donaldson, S.G. Factors Affecting Photolysis of Organic Compounds on Soils. In Helz, G.; Crosby D.G.; Zepp, R.G., eds. Surface and Aquatic Photochemistry, Lewis Publishers. 1993.

Minnesota Department of Agriculture. Minnesota pesticide sales information. Available online at http://www.mda.state.mn.us/chemicals/pesticides/useandsales.htm (verified September 2009), 2009b.

Minnesota Department of Agriculture. Pesticide usage on four major Minnesota crops. 2005. Available online at http://www.mda.state.mn.us/appd/pesticides/pesticideuse2003.pdf (verified September 2009)

Minnesota Department of Agriculture. Water quality BMPs for agricultural herbicides. Available online at http://www.mda.state.mn.us/protecting/bmps/herbicidebmps.htm (verified September 2009), 2009a.

Moon, J.-K.; Keum, Y.-S.; Hwang, E.-C.; Park, B.-S.; Chang, H.-R.; Li, Q.X.; Kim, J.-H. Hapten synthesis and antibody generation for a new herbicide, metamifop. J. Agric. Food Chem. 2007, 55, 5416-5422.

Moye, J. K. Use of a Homing Pigeon (Columba livia) Model to Assess the Effects of Cholinesterase Inhibiting Pesticides on Non-Target Avian Species. Environmental Sciences Program, University of Nevada-Reno. Master of Science: 2008, 97.

National Marine Fisheries Service Endangered Species Act Section 7 Consultation Biological Opinion Environmental Protection Agency Registration of Pesticides Containing Chlorpyrifos, Diazinon, and Malathion. 2008. http://www.nmfs.noaa.gov/pr/pdfs/pesticide_biop.pdf

National Marine Fisheries Service Endangered Species Act Section 7 Consultation Biological Opinion Environmental Protection Agency Registration of Pesticides Containing Carbaryl, Carbofuran, and Methomyl. 2009. http://www.nmfs.noaa.gov/pr/pdfs/carbamate.pdf

National Research Council. Risk Assessment in the Federal Government: Managing the Process, National Research Council, Natl. Acad. Press, Washington, DC, 1983.

Novak, J. M.; Moorman, T. B.; Cambardella, C. A. Atrazine sorption at the field scale in relation to soils and landscape position. J. Environ. Qual. 1997, 26, 1271-1277.

Nowell, L.H.; Capel, P.D.; Dileanis, P.D. Pesticides in Stream Sediment and Aquatic Biota: Distribution, Trends, and Governing Factors. Vol 4 of series, Pesticides in the Hydrologic System; CRC Press, Boca Raton, FL, 1999.

Olsson, B., Bradley, B.P., Gilek, M., Reimer, O., Shepard, J.L., Tedengren, M. Physiological and proteomic responses in Mytilus edulis exposed to PCBs and PAHs extracted from Baltic Sea sediments. Hydrobiologia 2004, 514,15-27.

Oregon State University. The Extension TOXicology NETwork (EXTOXNET) database. Available online at http://extoxnet.orst.edu (verified September 2009).

Papiernik, S. K.; Koskinen, W. C.; Yates, S. R. Solute transport in eroded and rehabilitated prairie landforms. 1. Nonreactive solute. J. Agric. Food Chem. 2009a 57, 7427-7433.

Papiernik, S. K.; Koskinen, W. C.; Yates, S. R. Solute transport in eroded and rehabilitated prairie landforms. 2. Reactive solute. J. Agric. Food Chem. 2009b, 57, 7434-7439.

Parrotta, C.D.; Rubio, F.; Li, Q.X.; Shelver, W.L. Development of a sensitive magnetic particle immunoassay for polybrominated diphenyl ethers. Organohalogen Compounds 2005, 67: 27-30.

Payne, J.; Rajapakse, N.; Wilkins, M.; Kortenkamp, A. Prediction and assessment of the effects of mixtures of four xenoestrogens. Environ. Health Persp. 2000, 108, 983-987.

Pelleguer, J.-L.; Chen, S.-W. W.; Karu, A.E.; Li, Q.X.; Roberts, V.A. Structural basis for preferential binding of non-ortho-substituted polychlorinated biphenyls by the monoclonal antibody S2B1. J. Mol. Recog. 2005, 18, 282-294.

Pesticide Action Network. PAN Pesticide Database. Available online at http://www.pesticideinfo.org (verified September 2009).

Petrovic, M.; Sole, M.; Lopez de Alda, M. J.; Barcelo, D. Endocrine disruptors in sewage treatment plants, receiving river waters, and sediment: Integration of chemical analysis and biological effects on feral carp. Environ. Toxicol. Chem. 2002, 21, 2146-2156.

Primbs, T.; Wilson, G.; Schmedding, D.; Higginbotham, C.; Massey Simonich, S. Influence of Asian and Western United States Agricultural Areas and Fires on the Atmospheric Transport of Pesticides in the Western United States. Environ. Sci. Technol. 2008, 42, 6519-6525.

Primbs, T.; Genualdi, S.; Massey Simonich, S. Solvent selection for pressurized liquid extraction of polymeric sorbents used in air sampling. Environ. Toxicol. Chem. 2008, 27, 1267-1272.

Rakotondravelo, M.L.; Anderson, T.D.; Charlton, R.E.; Zhu. K.Y. Sublethal effects of three pesticides on activities of selected target and detoxification enzymes in the aquatic midge, Chironomus tentans (Diptera: Chironomidae). Arch. Environ. Contam. Toxicol. 2006, 51, 360-366.

Ralston-Hooper, K.; Jannasch, A.; Oh, C.; Zhang, X.; Adamec, J.; Sepúlveda, M.S. Development of GCxGC/TOF-MS metabolomics for use in future invertebrate ecotoxicological studies. Aquatic Toxicol. 2008, 88,48-52.

Rice, P.J.; McConnell, L.L.; Heighton, L.P.; Sadeghi, A.M.; Isensee, A.R.; Teasdale, J.R.; Adbul-Baki, A.A.; Harman-Fetcho, J.A.; Hapeman, C.J. Runoff loss of pesticides and soil; A comparison between vegetative mulch and plastic mulch in vegetable production systems. J. Environ. Qual. 2001, 30, 1808-1821.

Rinella, Frank A., and Janet, Mary L. 1998. Seasonal and spatial variability of nutrients and pesticides in streams of the Willamette Basin, Oregon, 1993-95: U.S. Geological Survey Water-Resources Investigations Report 97-4082-C, 57 p.

Ross, L.J., Johnson, B., Kim, K.D., Hsu, J. (1999) Prediction of methyl bromide flux from area sources using the ISCST model. J. Environ. Qual. 25, 885-891.

Rui, Y.-K.; Yi, G.-X.; Zhao, J.; Wang, B.-M.; Li, Z.-H.; Zhai, Z.-X.; He, Z.-P.; Li, Q.X. Changes of Bt toxin in the rhizosphere of transgenic Bt cotton and its influence on soil functional bacteria. World J. Microbiol. Biotechnol. 2005, 21, 1279-1284.

Saltmiras, D.A.; Lemley, A.T. Atrazine degradation by anodic Fenton Treatment. Wat. Res. 2002, 36, 5113-5119.

Saltmiras, D.A.; Lemley, A.T. Anodic Fenton treatment of treflan MTF®. J. Environ. Sci. Health 2001, A36, 261-274.

Saltmiras, D.A.; Lemley, A.T. Degradation of ethylene thiourea (ETU) with three Fenton treatment processes. J. Agric. Food Chem. 2000, 48, 6149-6157.

Sanchez, B.C.; Ralston-Hooper, K.; Kowalski, K.A.; Inerowiczb, H.D.; Adamec, J.; Sepúlveda, M.S. Liver proteome response of largemouth bass (Micropterus salmoides) exposed to several environmental contaminants: potential insights into biomarker development. Aquatic Toxicol. 2009 (In Press).

Schwindt, A.R.; Kent, M.L.; Ackerman, L.K.; Massey Simonich, S.L.; Landers, D.H.; Blett, T.; Schreck, C.B. Reproductive abnormalities in trout from western U.S. National Parks. Trans. Am. Fisheries Soc. 2009, 138, 522-531.

Serpone, N.; Terzian, R.; Lawless, D.; Pelletier, A.M.; Minero, C.; Pelizzetti, E. Photocaatalyzed destruction of water contaminants. Chapt 25, In: G.R. Helz, R.G. Zepp; D.G. Crosy, eds. Aquatic and Surface Photochemisty, Lewis Publishers, Boca Raton. 1994.

Shelver, W.L.; Keum, Y.-S.; Kim, H.-J.; Rutherford, Drew; Hakk, Heldur H.; Bergman, Ake; Li, Q.X. Hapten syntheses and antibody generation for the development of polybrominated flame retardants ELISA. J. Agric. Food Chem. 2005b, 53, 840-3847.

Shelver, W.L.; Keum, Y.-S.; Li, Q.X.; Elliott, C.T. Development of an immunobiosensor assay for the beta-adrenergic agonist zilpaterol. J. Food Agric. Immunol. 2005c, 16, 199-211.

Shelver, W.L.; Kim, H.-J.; Li, Q.X. Development of monoclonal antibody based ELISA for the b-adrenergic agonist zilpaterol. J. Agric. Food Chem. 2005a, 53, 3273-3280.

Shelver, W.L.; Parrotta, C.D.; Slawecki, R.; Li, Q. X.; Ikonomou, M.G.; Barcelo, D.; Lacorte, S.; Rubio, F.M. Development of a magnetic particle immunoassay for polybrominated diphenyl ether and application to environmental and food matrices. Chemosphere 2008, 73, S18S23.

Sheng, W.; Xia,; X.; Wei, K.; Li, J.; Li, Q.X.; Xu, T. Determination of marbofloxacin residues in beef and pork with an enzyme-linked immunoadsorbent assay. J. Agric. Food Chem. 2009a, 57, 5971-1975.

Sheng, W.; Xu, T.; Ma, H.H.; Wang, X.T.; Li, Q.X.; Li, J. Development of an indirect competitive enzyme-linked immunosorbent assay for detection of danofloxacin residues in beef, chicken and pork meats. Food Agric. Immunol. 2009b, 20, 35-47.

Silva, E.; Rajapakse, N.; Kortenkamp, A. Something from nothing  eight weak estrogenic chemicals combined at concentrations below NOECs produce significant mixture effects. Environ. Sci. Technol. 2002, 36, 1751-1756.

Siuti, N.; Kelleher, N.L.. Decoding protein modifications using top-down mass spectrometry. Nat. Methods 2007, 4, 817-821.

Smith, A.E.; Bridges, D.C. Movement of certain herbicides following application to simulated golf course greens and fairways. Crop Sci. 1996, 36, 1439-1445

Stanley, K.; Massey Simonich, S.; Bradford, D.; Davidson, C.; Tallent-Halsell, N. Comparison of pressurized liquid extraction and matrix solid phase dispersion for the measurement of semi-volatile organic compound accumulation in tadpoles. Environ. Toxicol. Chem. 2009, 28, 2038-2043.

Sterling, T.M.; Lownds, N.K. Picloram absorption by broom snakeweed (Gutierrezia sarothrae) leaf tissue. Weed Sci. 1992, 40, 390394.

Sterling, T.M.; Lownds, N.K.; Murray, L.W. Picloram uptake and picloram-induced ethylene production by broom snakeweed as influenced by environment. J. Range Manag. 1996, 49, 245250.

Sterling, T.M.; Thompson, D.C.; Abbott, L.A. Implications of invasive plant variation for weed management. Weed Technol. 2004, (in press).

Sudakin, D.; Power, L.E. Regional and temporal variation in methamphetamine-related incidents: applications of spatial and temporal scan statistics. Clin. Toxicol. 2009, 47, 243-247.

Sudakin, D.L.; Horowitz, Z.; Giffin, S. Regional variation in the incidence of symptomatic pesticide exposures: applications of geographic information systems. J. Toxicol. Clin. Toxicol. 2002, 40, 767-773.

Sur, H.S., Mastana, P.S.; Hadda, M.S. Effect of rates and modes of mulch application on runoff, sediment and nitrogen loss on cropper and uncropped fields. Trop. Agric. 1992. 69, 319-322.

Susarla, S.; Collette, T.W.; Garrison, A.W.; Wolfe, N.L.; McCutcheon, S.C. Perchlorate identification in fertilizers. Environ. Sci. Technol. 1999, 33, 3469-3472.

Syka, J.E.P.; Coon, J.J.; Schroeder, M.J.; Shabanowitz, J.; and Hunt, D.F. Peptide and protein sequence analysis by electron transfer dissociation mass spectrometry. Proc. Natl. Acad. Sci. U.S.A. 2004, 101:9528-9533.

Tadeo, J.L. (Ed). Analysis of Pesticides in Food and Environmental Samples. 2008. pp384, CRC Press.

Thomas, J.E.; Ou, L.T.; Al-Agely, A. DDE degradation and remediation In: Whitacre, D.M.; ed., Reviews of Environmental Contamination and Toxicology, 2008, Series 194, Chap. 3, pp. 55-69.

Thorpe, K.L.; Gross-Sorokin, M.; Johnson, I.; Brighty, G.; Tyler, C.R. An assessment of the model of concentration addition for predicting the estrogenic activity of chemical mixtures in wastewater treatment works effluents. Environm. Health Persp. 2006, 114S, 90-97.

Thurman, E.M.; Goolsby, D.A.; Meyer, M.T.; Kolpin, D.W. Herbicides in surface waters of the Midwestern United States: The effect of spring flush. Environ. Sci. Technol. 1991, 25, 1794-1796.

Thurman, E.M.; Goolsby, D.A.; Meyer, M.T.; Mills, M.S.; Pones, M.L.; Kolpin, D.W.A reconnaissance study of herbicides and their metabolites is surface water of the Midwestern United States using immunoassay and gas chromatography/mass spectrometry. Environ. Sci. Technol. 1992, 26, 2440 2447.

Tittabutr, P.; Awaya, J.D.; Li, Q.X.; Borthakur, D. The cloned 1-aminocyclopropane-1-carboxylate (ACC) deaminase gene from Sinorhizobium sp. strain BL3 in Rhizobium sp. strain TAL1145 promotes nodulation and growth of Leucaena leucocephala. Syst. Applied Microb. 2008, 31, 141-150.

U.S. Geological Survey. The water cycle: snowmelt runoff. Available online at http://ga.water.usgs.gov/edu/watercyclesnowmelt.html (verified September 2009).

U.S.Geological Survey. USGS Scientific Investigations Report 2008-5027, "Pesticide Occurrence and Distribution in the Lower Clackamas River Basin, Oregon, 2000-2005 (http://pubs.usgs.gov/sir/2008/5027/)."

Usenko, S.; Landers, D.; Appleby, P.; Simonich, S.L. Current and historical deposition of PBDEs, pesticides, PCBs, and PAHs to Rocky Mountain National Park, USA: Does the continental divide make a difference?, Environ. Sci. Technol. 2007, 41, 7235-7241

Usenko, S.; Hageman, K.J.; Schmedding, D.W.; Wilson, G.R.; Simonich, S.L. Trace analysis of semi-volatile organic compounds in large volume samples of snow, lake water, and groundwater. Environ. Sci. Technol. 2005, 39, 6006-6015.

Wallvoord, M.A.; Phillips, F.M.; Stonestrom, D.A.; Evans, R.D.; Hartsough, P.D.; Newman, B.D.; Streigl, R.G. A reservoir of nitrate beneath desert soils. Science 2003, 302, 1021-1024.

Wang, Q.; Lemley, A.T. Competitive degradation and detoxification of carbamate insecticides by membrane anodic Fenton treatment. J. Agric. Food Chem. 2003a, 51, 5382-5390.

Wang, Q.; Lemley, A.T. Kinetic model and optimization of 2,4-D degradation by anodic Fenton treatment. Environ. Sci. Technol. 2001, 35,4509-4514.

Wang, Q.; Lemley, A.T. Oxidative degradation and detoxification of aqueous carbofuran by membrane anodic Fenton treatment. J. Hazard. Mat. 2003b, B98, 241-255.

Wang, Q.; Scherer, E; Lemley, A.T. Metribuzin degradation by membrane anodic Fenton treatment and its interaction with ferric ion. Environ. Sci. Technol. 2004, 38,1221-1227.

Wang, Q; Lemley, A.T. Oxidation of carbaryl in aqueous solution by membrane anodic Fenton treatment. J. Agric. Food Chem 2002, 50, 2331-2337.

Wang, Q; Lemley, A.T. Reduced adsorption of ametryn in clay, humic acid, and soil by interaction with ferric ion under Fenton treatment conditions. J. Environ. Sci.Health Part B 2006, 41, 223-236.

Wang, Z.; Casler, M.D.; Stier, J.C.; Gregos, J.S.; Millett, S.M. Genotypic variation for snow mold reaction among creeping bengrass clones. Crop Sci. 2005, 45, 399-406.

Watson, W.A.; Litovitz, T.L.; Belson, M.G.; Funk Wolkin, A.B.; Patel, M.; Schier, J.G.; Reid, N.E.; Kilbourne, E.; Rubin, C. The Toxic Exposure Surveillance System (TESS): Risk assessment and real-time toxicovigilance across United States poison centers. Toxicol. Appl. Pharmacol. 2005, 207, 604-610.

Wetmore, B.A.; Merrick, B.A. Toxicoproteomics: proteomics applied to toxicology and pathology. Toxicol. Pathol. 2004, 32:619-642.

Wilson, B.W.; Henderson, J.D.; Furman, L.; Zeller, B.E.; Michaelsen, D. Blood cholinesterases from Washington State orchard workers. Bull. Environ. Contam. Toxicol. 2009a, 83, 462.

Wilson, B.W.; Henderson, J.D.; Furman, J.L.; Zeller, B.E.; Michaelson, D. Blood cholinesterases from Washington State orchard workers. Bull. Environ. Contam. Toxicol. 2009b, 83, 59-61.

Xu, T.; Jacobsen, C.M.; Cho, I.K.; Hara, A.H.; Li, Q.X. Application of an enzyme-linked immunosorbent assay for the analysis of imidacloprid in wiliwili tree, Erythrina sandwicensis O. Deg for Control of the wasp Quadrastichus erythrinae. J. Agric. Food Chem. 2006, 54, 8444-8449.

Xu, T.; Jing, H.Y.; Li, Q.X.; Sheng, W.; Li, J. Development of an enzyme-linked immunosorbent assay for the detection of pentachlorophenol residues in water samples. Food Agric. Immunol. 2007a, 18, 189-201.

Xu, T.; Shao, X.L.; Li, Q.X.; Jing, H.Y.; Sheng, W.; Wang, B.M.; Li, J. Development of an enzyme-linked immunosorbent assay for the detection of pentachloronitrobenzene residues in environmental samples. J. Agric. Food Chem. 2007b, 55, 3764-3770.

Xu, T.; Sheng, W.; Wang, B.-M.; Shao, X.-L.; Li, Q.X.; Gao, H.-B.; Li, L. Application of an enzyme-linked immunosorbent assay for the detection of clenbuterol residues in swine urine and feeds. J. Environ. Sci. Health Part B. 2007c, 42:173-177

Xu, T.; Cho, I.K.; Wang, D.; Rubio, F.M.; Shelver, W.L.; Gasc, A.M.E.; Li, J.; Li, Q.X. Suitability of a magnetic particle immunoassay for the analysis of PBDEs in Hawaiian euryhaline fish and crabs in comparison with gas chromatography/electron capture detection-ion trap mass spectrometry. Environ. Pollut. 2009a, 157, 417-422.

Xu, T.; Jacobsen, C.M.; Hara, A.H.; Li, J.; Li, Q.X. Efficacy of systemic insecticides on the gall wasp Quadrastichus erythrinae in wiliwili trees Erythrina spp. Pest Manag. Sci. 2009b, 65,163-169.

Yang, Y.H.; Dudoit, S.; Luu, P.; Lin, D.M.; Peng, V.; Ngai, J.; Speed, T.P. Normalization for cDNA microarray data: a robust composite method addressing single and multiple slide systematic variation. Nucleic Acids Res. 2002, 30, e15.

Ye, P.; Lemley, A.T. Adsorption effect on the degradation of carbaryl, mecoprop and paraquat by Anodic Fenton Treatment in an Swy-2 montmorillonite clay slurry. J. Agric. Food Chem. 2008, 56, 1020010207.

Ye, P; Lemley, A.T. Adsorption effect on the degradation of 4,6-o-dinitrocresol and p-nitrophenol in a montmorillonite clay slurry by AFT. J. Water Res. 2009b, 43, 13031312.

Ye, P, Kong, L.; Lemley, A.T. Kinetics of carbaryl degradation by anodic Fenton treatment in a humic acid amended artificial soil slurry. Wat. Env. Res.2009a, 81, 29-39.

Zeng, X; Lemley, A.T. Fenton Degradation of 4,6-dinitro-o-cresol with Fe2+ Substituted Ion Exchange Resin. J. Agric. Food Chem. 2009, 57, 36893694.

Zhang, H.; Lemley, A.T. Evaluation of the performance of flow-through anodic Fenton treatment in amide compounds degradation.. J. Agric. Food Chem. 2007, 55, 4073-4079.

Zhang, H; Lemley, A.T. Reaction mechanism and kinetic modeling of DEET degradation by flow-through anodic Fenton treatment (FAFT). Environ. Sci. Technol. 2006, 40,4488-4494.

Zhao, J.; Li, G.; Wang, B.-M.; Liu, W.; Nan, T.-G.; Zhai, Z.-X.; Li, Z.-H.; Li, Q.X. Development of a monoclonal antibody-based enzyme-linked immunosorbent assay for the analysis of glycyrrhizic acid. Anal. Bioanal. Chem. 2006a, 386, 1735-1740.

Zhao, J.; Li, G.; Yi, G.-X.; Wang, B.-M.; Deng, A.-X.; Nan, T.-G.; Li, Z.H.; Li, Q.X. Comparison between conventional indirect competitive enzyme-linked immunosorbent assay (icELISA) and simplified icELISA for small molecules. Analytica Chimica Acta 2006b, 571, 79-85.

Zhao, J.; Yi, G.-X.; Wang, B.-M.; Li, G.; Li, Z.-H.; Li, Q.X. Development of a monoclonal antibody-based enzyme-linked immunosobent assay for the herbicide chlorimuron-ethyl. J. Agric. Food Chem. 2006c, 54, 4948-4953.

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