W3045: Agrochemical Impacts On Human And Environmental Health: Mechanisms And Mitigation

(Multistate Research Project)

Status: Inactive/Terminating

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Annual/Termination Reports:

[07/01/2016] [07/01/2017] [08/09/2018] [07/17/2019]

Date of Annual Report: 07/01/2016

Report Information

Annual Meeting Dates: 06/05/2016 - 06/07/2016
Period the Report Covers: 10/01/2015 - 09/30/2016

Participants

Kevin Armbrust, Louisiana State Agricultural Experiment Station
Allan Felsot, Washington State Agricultural Experiment Station
Cathleen Hapeman, USDA-ARS Beltsville MD
Vince Hebert, Washington State Agricultural Experiment Station
Jeff Jenkins, Oregon State Agricultural Experimental Station
Qing Li, Hawaii Agricultural Experiment Station
Glenn Miller, Nevada Agricultural Experiment Station
Bob Peterson, Montana State Agricultural Experimental Station
Chris Pritsos, Nevada Agricultural Experiment Station; W-3045 Administrative Advisor
Michael Sadowsky, Minnesota Agricultural Experiment Station
Tracy Sterling, Montana State Agricultural Experiment Station

Brief Summary of Minutes

Minutes Attachment:

2016 W-3045 Meeting Minutes.pdf

Accomplishments

Objective 1: Identify, develop, and/or validate trace residue analytical methods, immunological procedures, and biomarkers   Washington, Hebert: A major impediment in conducting quantitative biomonitoring within epidemiology studies is the lack of rapid, sensitive, field deployable technologies that measure chemical exposure biomarkers using minimally invasive biological fluids (i.e. saliva, drop of blood or urine). Due to the complexity of occupational exposures and biological systems, measurement of a single biomarker may not an adequate quantitative assessment of exposure. Hence, this project will undertake development, validation, and refinement of a novel multiplex sensor platform capable of quantifying multiple biomarkers associated with pesticide exposures, utilizing saliva, blood, and urine as relevant biological fluids. Validation of this multiplex sensor project will initially focus on chlorpyrifos, diazinon, carbaryl and atrazine and their associated metabolites that are well investigated to be readily excreted in saliva and correlate with blood concentration. A major initial aim will be to compare the responsiveness of the multiplex biosensor system in concert with chromatographic analytical methods in relevant biological matrixes. Results from these validation studies will establish the feasibility and capability to measure very low exposures approaching the current occupational exposures for each analyte.   Objective 2: Characterize abiotic and biotic reaction mechanisms, transformation rates, and fate in agricultural and natural ecosystems   Louisiana, Armbrust: The fungicide 2,6-dichloro-4-nitroaniline (DCNA) is applied to crops grown in areas near both freshwater and saltwater bodies and it can enter the surface waters where it is susceptible to photolysis. The salinity of seawater can influence both the overall rate of degradation of chemicals and impact the distribution and types of photoproducts generated during the photodegradation process. The photodegradation of DCNA was measured in distilled water, artificial seawater, estuarine water, and phosphate buffer to determine the degree of differences in the degradation rate in various matrices. The brominated analogue 2,6-dibromo-4-nitroaniline (DBNA) was measured identically to determine the impacts of other halogens on the degradation process. Solutions of DCNA and DBNA at a concentration of 1 ppm were prepared and irradiated for 24 hours in an Atlas SUNTEST XXL+ photochamber that mimics the wavelength distribution and intensity of sunlight. Dark controls were run simultaneously. Samples were withdrawn at 0, 2, 4, 6, 12, and 24 hours and analyzed for residual DCNA or DBNA using an Agilent 1260 Infinity High Performance Liquid Chromatograph. The formation of ions such as nitrate, nitrite, bromide, and chloride were measured using a Thermo Dionex ICS-5000+ Ion Chromatograph. The half-life of DCNA in distilled water was calculated to be 7.62 ± 0.094 hours and 7.37 ± 0.279 hours in artificial seawater; statistically there was no significant difference in the degradation rate through the first half-life. Analysis of the quick formation of nitrite and chloride ions, and later formation of nitrate ions, suggests photonucleophilic substitution processes are occurring as the compound is degrading, followed by further degradation of nitrite to nitrate likely also due to photolysis processes. Small aliphatic acids, maleic and fumaric acid, were detected after 12 hours of irradiation by HPLC indicating degradation of the aromatic ring structure. Differences in formation rate and decline for intermediate photoproducts were observed in seawater and distilled water suggesting salinity affects the rate of formation of this photoproduct.   Maryland, Hapeman: Riparian buffers are known to mitigate hydrologic losses of nutrients and other contaminants as they exit agricultural fields. The vegetation of riparian buffers can also trap atmospheric contaminants, which can subsequently be delivered via rain to the riparian buffer floor. Stemflow is rain contacting the tree canopy traveling down smaller to larger branches and down the tree trunk, whereas throughfall is rain that may or may not contact leaves and branches and falls to the floor. These processes, however, are poorly understood especially for pesticide residues. Therefore, we conducted a four-year study examining stemflow and throughfall within and precipitation outside a riparian buffer which was adjacent to a corn field. Stemflow concentrations were larger than throughfall concentrations and were larger for metolachlor than atrazine. Larger depositional fluxes were measured when leaves were more fully emerged and when temperatures and humidity were elevated. Enhanced herbicide loading to the riparian buffer stream was found to be linked to tree canopy deposition and subsequent washoff during rain events. These results indicate that during low overland-flow precipitation events, the tree canopy can be a dominant pesticide source to surface waters.   Nevada, Miller: Biofuel crops can potentially be grown on arid lands that do not compete with other food and feed crops. Grindelia squarrosa, commonly known as gumweed, is a flowering plant species common to Nevada that is found in many areas of the inter-mountain west, particularly along roadsides where increased precipitation is available from runoff. A preliminary analysis of numerous desert plants by Lemaire in 1982 (unpublished) singled out gumweed as a strong candidate for crude oil production. High oil yield per acre, along with minimal watering requirements, makes gumweed a strong crop for biodiesel production in the western United States. Processed gumweed has provided an average of 12-23 % crude oil by dry weight, depending on the plant stand collected and the method of sample drying. While the majority of hydrocarbons present in the extracts are at the heavy end of diesel fuel, a derivatized B20 blended biodiesel was shown to meet ASTM standards for flash point, kinematic viscosity, and sulfur content. Gumweed biodiesel blends offer a useful source of additional fuel that can be produced from crops grown in arid environments with minimal irrigation needs, while reducing the competition between food and biofuel crops. No additional engine modifications are needed for the use of B5 or B20 biofuels. Additionally, we have investigated the direct conversion of biocrude into a potentially usable jet/diesel fuel via pyrolysis. Heating the biocrude to 400 oC produced a decarboxyated mixture of compounds. The two major compounds were tri- and tetramethlyltetralin. Tetralins are compounds similar to naphthalene that contain one of the rings saturated and the other aromatic. Further investigation of this process is warranted, since the yield of the distillate from the biocrude is approximately 45% (by weight). Additional characterization of this product is required to fully characterize the distillate.   Oregon, Jenkins: For more than 20 years pesticides have consistently been detected in the Zollner Creek watershed, Willamette Basin, OR, more frequently, and at higher levels, than in other surface waters of the Pacific Northwest. To address this concern the watershed scale ecohydrologic model – Soil and Water Assessment Tool (SWAT) – was used to better understand pesticide loading pathways that may direct the development of mitigation strategies. Using a mechanistic approach to refining ecohydrology, SWAT deterministic parameterization scenarios of increasing local knowledge were evaluated in relation to USGS observed average daily stream flow near the outlet of the watershed. Uncertainty of selected model inputs was further investigated using a probabilistic approach; statistics used to evaluate model performance – PBIAS, NSE, RSR, R2 – were improved and deemed acceptable for the evaluation of pesticide fate. To evaluate model performance in estimating pesticide fate, probabilistic methods were used to evaluate the spatial and temporal distribution of atrazine applications and resulting surface water concentration profiles. Model estimates – mean atrazine surface water concentration and 95% confidence interval as a result of the spatial and temporal probability distributions of atrazine applications – for 2010 and 2011 are compared to USGS and Oregon DEQ atrazine grab sample surface water concentrations. Ninety-two percent of grab samples were within a factor of 4 of SWAT mean estimates of atrazine concentrations. This modeling approach shows promise in estimating pesticide surface water concentration exceedance probabilities for alternate cropping practices, mitigation measures, and pest management strategies.         Objective 3: Determine adverse impacts from agrochemical exposure to cells, organisms, and ecosystems   Montana, Peterson: The insecticides currently used for management of adult mosquitoes are broad-spectrum and highly toxic to most bees, but toxicity is not the same thing as risk. Moreover, risk information is not available for real-world exposures of bee pollinator species to insecticides used for mosquitoes. Therefore, we are conducting insecticide susceptibility research on the honey bee (Apis mellifera) and the alfalfa leafcutting bee (Megachile rotundata), an important non-honey bee pollinator in the western U.S. that can also serve as a surrogate for other solitary bees. This two-year research study encompasses three primary objectives that are providing knowledge about the risks to bees from exposure to insecticides. The objectives are to determine: (1) LD50 values (the dose that causes 50% mortality) for alfalfa leafcutting bees when exposed to three pyrethroid insecticides; (2) the effects on foraging alfalfa leafcutting bees and honey bees the day after field applications of pyrethroids; and (3) the effects on populations of alfalfa leafcutting bees after field applications of permethrin directly on nest boxes. Data from 2015 are presented here for objectives 1 and 2. Preliminary LD50 values were estimated for permethrin, etofenprox, and deltamethrin. LD50 values for female alfalfa leafcutting bees were 0.04 µg/bee for etofenprox (slope, 4.093; heterogeneity, 1.12), 0.048 µg/bee for permethrin (slope, 6.266; heterogeneity, 1.33), and 0.0032 µg/bee for deltamethrin (slope, 6.893; heterogeneity, 1.22). These LD50 values are approximately twice the values for honey bee, indicating that alfalfa leafcutting bees are about twice as tolerant. Preliminary results indicate that there were no statistically significant effects on mortality of alfalfa leafcutting bees and honey bees after permethrin and etofenprox were sprayed at maximum label rates directly over alfalfa fields. Control mortality and treatment mortality were very low and not statistically different (p-value range = 0.28 – 0.99).   Montana, Sterling: Smooth brome (Bromus inermis Leyss.) is a cool-season, perennial grass that spreads by rhizomes and was introduced in the 1880s as a livestock forage and for erosion control; it grows across North America in proximity to wheat-growing regions, and is considered weedy in some habitats. The major wheat pest, wheat stem sawfly (Cephus cinctus Norton) causes $350 million of annual damage in wheat fields throughout the Northern Great Plains. Insecticides are not effective in this pest system, but smooth brome may be an alternate host and serve as a perimeter trap; however, no empirical data exist to demonstrate its effectiveness. We used a combination of laboratory analysis and field sampling to evaluate smooth brome’s role as an alternate host. In the lab, we identified and quantified attractive volatile compounds from wheat and smooth brome using GC-MS. In the field, we sampled smooth brome adjacent to wheat fields and monitored the number of eggs, larvae, and parasitoids in each species through the growing season. Smooth brome produced the same attractive green leaf volatile compounds as wheat, but at 4- to 8-fold higher concentrations. In the field, a greater proportion of smooth brome stems were infested with wheat stem sawfly eggs than wheat stems in adjacent fields. Among infested stems, smooth brome had more eggs per stem than wheat. These results suggest a proof of concept that smooth brome chemistry plays a role in its efficacy as a trap for wheat stem sawfly management.   Washington, Felsot: A comparative assessment of apiaries in urban, rural and agricultural areas was undertaken in 2013 and 2014 to examine potential honey bee colony exposure to neonicotinoid insecticides from pollen foraging.   Apiaries ranged in size from one to hundreds of honey bee colonies, and included those operated by commercial, sideline (semi-commercial) and hobbyist beekeepers. Residues in/on wax and beebread (stored pollen in the hive) were evaluated for the nitro-substituted neonicotinoid insecticides imidacloprid and its olefin metabolite and the active ingredients clothianidin, thiamethoxam, and dinotefuran.  Beebread and comb wax collected from hives in agricultural landscapes were more likely to have detectable residues of thiamethoxam and clothianidin than that collected from hives in rural or urban areas (~50% of samples vs <10%).  The maximum neonicotinoid residue detected in either wax or beebread was 3.9 ppb imidacloprid.  A probabilistic risk assessment was conducted on the residues recovered from beebread in apiaries located in agricultural, urban, and rural landscapes.  The calculated risk quotient based on a dietary no observable adverse effect concentration (NOAEC) suggested low potential for negative effects on bee behavior or colony health.     Objective 4: Develop technologies that mitigate adverse human and environmental impacts   Hawaii, Li: Polycyclic aromatic hydrocarbons (PAHs), a class of priority hazardous substances, are persistent, ubiquitous and carcinogenic. Bioremediation is an economical technology to degrade PAHs. Understanding mechanisms of PAH toxicity and bioavailability to bacteria allows optimization of factors for bioremediation efficiency. Burkholderia sp. C3 degrades PAHs including dibenzothiophene (DBT) that is typically used as a model PAH for bioremediation studies. Chemical biodegradation, bacterial growth and toxicity studies showed that glycerol, a biodiesel production byproduct, enhanced DBT biodegradation kinetics by 18-fold in C3. Surface tension measurement, metabolite analysis and gene cloning identified secretion of rhamnolipids, glycolipid biosurfactants, by C3. Rhamnolipid fortification experiments further confirmed the relevance of rhamnolipids to the enhanced DBT biodegradation. The use of β-oxidation and rhamnolipid synthesis inhibitors reduced C3 growth and DBT biodegradation rate. It is concluded that that glycerol supports C3 growth and co-metabolism of DBT via a rhamnolipid mediated mechanism. This study provided insights into mechanisms of glycerol induced co-metabolism of DBT in Burkholderia sp. C3, which will allow to design effective bioremediation strategies to remove PAHs from contaminated sites.

Publications

Impact Statements

Judicious use of agrochemicals and other man-made chemicals will demand practical knowledge of their fate and effects in agricultural and natural ecosystems. The directed multi-institutional federal-state and interdisciplinary research efforts combined with state experimental station outreach reported herein facilitates the development and adoption of economic technologies that improve pest management while minimizing adverse human and environmental impacts.

Date of Annual Report: 07/01/2017

Report Information

Annual Meeting Dates: 06/06/2017 - 06/08/2017
Period the Report Covers: 05/01/2016 - 04/30/2017

Participants

Kevin Armbrust, Louisiana State Agricultural Experiment Station
Jay Gan, California Agricultural Experiment Station
Jeff Jenkins, Oregon State Agricultural Experiment Station
Qing Li, Hawaii Agricultural Experiment Station
Glenn Miller, Nevada Agricultural Experiment Station
Bob Peterson, Montana State Agricultural Experiment Station
Chittaranjan Ray, Nebraska Agricultural Experiment Station
Marisol Sepulveda, Indiana Agricultural Experiment Station
Chris Pritsos, Nevada Agricultural Experiment Station; W-3045 Administrative Advisor

Brief Summary of Minutes

Minutes Attachment:

2017 W-3045 Meeting Minutes.pdf

Accomplishments

Objective 1: Identify, develop, and/or validate trace residue analytical methods, immunological procedures, and biomarkers  Hawaii, Li: Exploring Adduct Formation between Human Serum Albumin and Eleven Organophosphate Ester Flame Retardants and Plasticizers using MALDI-TOF/TOF and LC-Q/TOF. Toxicant-protein adducts are valuable biomarkers for retrospective verification of exposure. In the present study, our goal was to determine whether organophosphate ester (OPE) flame retardants (OPE FRs) and plasticizers can covalently bind to human serum albumin (HSA) and can be used to evaluate their exposure. Eleven OPE FRs and plasticizers were examined in a HSA-adduct in vitro assay. Pure HSA was incubated with the target OPEs, as well as with an OP insecticide (profenofos) positive control. After enzymatic cleavage with pepsin or Glu-C, the digested albumin was analyzed by matrix-assisted laser desorption ionization tandem time-of-flight mass spectrometry and liquid chromatograph-quadrupole time-of-flight mass spectrometry. Under optimized HSA assay conditions, tyrosine adducts were formed at Y411 and Y148/Y150 with a characteristic mass shift for phosphorylation (∆m/z 166) for the profenofos positive control. However, no such phosphorylated peptides were detected for the 11 target OPEs. This negative result suggests that these OPEs have very different affinities from the OP insecticide. They are less reactive or may specifically interact with other proteins. Objective 2: Characterize abiotic and biotic reaction mechanisms, transformation rates, and fate in agricultural and natural ecosystems Louisiana, Armbrust: Salinity Impacts on Pesticide Water Solubility and n-Octanol/Water Partition Coefficients. Salinity has been reported to influence the water solubility of organic chemicals entering marine ecosystems. However, there is limited data available on salinity impacts for chemicals potentially entering seawater. Impacts on water solubility would correspondingly impact chemical sorption as well as overall bioavailability and exposure estimates used in the regulatory assessment. The pesticides atrazine, fipronil, bifenthrin, cypermethrin, as well as the crude oil constituents dibenzothiophene and three of its alkyl derivatives all have different polarities and were selected as model compounds to demonstrate the impact of salinity on their solubility and partitioning behavior. The n-octanol/water partition coefficient (KOW) was measured in both distilled-deionized water as well as artificial seawater (3.2&permil;). All compounds had diminished solubility and increased KOW values in artificial seawater as compared to distilled-deionized water. A linear correlation curve estimated salinity may increase the log KOW value 2.6% per one log unit increase in distilled water (R2 = 0.968). Salinity appears to generally decrease the water solubility and increase partitioning potential. Environmental fate estimates based upon these parameters indicate elevated chemical sorption to sediment, overall bioavailability, and toxicity in artificial seawater. These dramatic differences suggest that salinity should be taken into account when conducting exposure estimates for marine organisms. California, Gan: Degradation of Pyrethroids and Formation of 3-Phenoxybenzoic Acid on Urban Impervious Surfaces. Urban insecticide use including structural pest control and landscape maintenance accounts for a large fraction of the total insecticide use. For instance, in California, reported urban insecticide use in 2014 amounted to 1.8 million kg (as active ingredients), of which 1.77 × 105 kg was synthetic pyrethroids. Pyrethroid use has been associated with acute toxicity to water column and benthic invertebrates in urban streams. Many pyrethroids may be transformed to a common intermediate, 3-phenoxybenzoic acid (3-PBA), an endocrine disrupting compound. However, little is known about the formation of 3-PBA from pyrethroids in urban settings. In this study, we examined the stability of five common pyrethroids, permethrin, lambda-cyhalothrin, deltamethrin, fenpropathrin, and esfenvalerate, on concrete surfaces and the derivation of 3-PBA under sunlight. Irreversible binding, hydrolysis, photolysis and volatilization led to rapid dissipation of pyrethroids on irradiated concrete. Formation of 3-PBA was almost instantaneous, reaching up to 3% of the initial level of pyrethroids within hours of exposure, and was caused mainly by hydrolysis, likely enhanced by the strong alkalinity of concrete. The formation of 3-PBA on concrete further varied among the different compounds, and was transient, with an average half-life of 4.2-6.7 h. Trace levels of 3-PBA were consistently found in two streams draining urban neighborhoods, suggesting that urban use of pyrethroids resulted in 3-PBA contamination of urban surface waters. Findings from this study suggested that urban hardscapes such as concrete pavement are reactive surfaces, highlighting the need to consider formation of biologically active intermediates such as 3-PBA from urban-use pesticides. Nevada, Miller: Grindelia squarrosa: A Potential Arid Lands Biofuel Plant. Gumweed (Grindelia squarrosa) is an arid lands plant that contains approximately 12-14% acetone extractable hydrocarbons. Gumweed is a naturally occurring plant of the intermountain west that can be grown with very limited additional irrigation water on arid lands not suitable for most food crops. The acetone extract of mature, ground gumweed produces a biocrude that is approximately 52% grindelic acid, a C20 diterpene acid. When the biocrude is pyrolyzed and distilled, the distillate contains a variety of compounds that can potentially be utilized as a biofuel. The crude distillate obtained from pyrolysis (heating slowly from 200oC to 450oC in 3-4 hours) was further fractionated into three fractions, based on their boiling points. The first cut (73-134oC) was light yellow and consisted of cycloalkenes, alkyl benzenes and trace amounts of alcohols with comparatively lower freezing point but higher acid number. The second cut (134-172oC) was light green and consisted of two tetralin compounds, 1,1,6-trimethyl-1,2,3,4-tetrahydronapthalene (C13H18) and 5,6,7,8-tetramethyl-1,2,3,4-tetrahydronapthalene (C14H20) which constitutes about 29 percent of the biocrude by weight. The third cut (172-213 oC) was a darker green and consists of 5,6,7,8-tetramethyl-1,2,3,4-tetrahydronapthalene (C14H20) as major constituent and other higher molecular weight hydrocarbons with relatively higher freezing point but lower acid number. These tetralins have properties that can potentially qualify them as biojet fuels, based the branched structure of the molecules, freezing point, cloud point, density, heating value and acid number. The average biannual production of those second and third cut biofuel fractions was 570 liters per hectare (l/ha) (61 gallons per acre (gal/ac)) with the range of 475 l/ha (51 gal/ac) to 664 l/ha (71 gal/ac) when gumweed was cultivated in plots at the Nevada Agricultural Experiment Station. Objective 3: Determine adverse impacts from agrochemical exposure to cells, organisms, and ecosystems Montana, Peterson: Risks to Pollinating Bees from Adult Mosquito Management. The insecticides currently used for management of adult mosquitoes are broad-spectrum and highly toxic to most bees, but toxicity is not the same thing as risk. In addition, risk information is not available for real-world exposures of bee pollinator species to insecticides used for mosquitoes. Therefore, we are conducting insecticide susceptibility research on the honey bee (Apis mellifera) and the alfalfa leafcutting bee (Megachile rotundata), an important non-honey bee pollinator in the western U.S. that may also serve as a surrogate for other solitary bees. This two-year research study encompasses three primary objectives that are providing knowledge about the risks to bees from exposure to insecticides. The objectives are to determine: (1) LD50 values (the dose that causes 50% mortality) for alfalfa leafcutting bees when exposed to three pyrethroid insecticides; (2) the effects on foraging alfalfa leafcutting bees and honey bees the day after field applications of pyrethroids; and (3) the effects on populations of alfalfa leafcutting bees after field applications of etofenprox directly on nest shelters. Results from 2015 and 2106 are presented here. LD50 values for female alfalfa leafcutting bees were 0.051 µg/bee for etofenprox, 0.057 µg/bee for permethrin, and 0.0016 µg/bee for deltamethrin. These LD50 values for permethrin and etofenprox were more than twice the values for honey bee, indicating that alfalfa leafcutting bees may be approximately twice as tolerant. We also characterized respiration rates after dosing at the LD50 level. Respiration rates comparing each active ingredient to control groups were statistically different (P<0.0001) as well as rates between each active ingredient (P<0.0001). There was no significant increase in mortality of alfalfa leafcutting bees or honey bees after exposure of alfalfa leaves and flowers to maximum label rates of permethrin, etofenprox, and deltamethrin. Effects on populations after direct treatment with etofenprox have not been observed. Results analyzed to date indicate no significant differences in percentages of survivorship (p=0.78), unknown mortality (p=0.18), parasitoid mortality (p=0.94), or pollen ball mortality (p=0.36) between untreated nest shelters and nest shelters treated with etofenprox. Indiana, Sepulveda: Uptake and Depuration of Four Perfluoroalkyl Acids (PFAAs) in the Northern Leopard Frog Lithobates pipiens Tadpoles. Per/polyfluoroalkyl acids (PFAAs) are an emerging group of persistent organic contaminants that are ubiquitous in surface waters. To date, their effects on aquatic systems, especially amphibians, are poorly understood. We examined the uptake and depuration of perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate (PFHxS), perfluorooctanoic acid (PFOA), and 6:2 telomer sulfonate (6:2 FTS) in northern leopard frog (Lithobates pipiens) tadpoles. We quantified whole-body concentrations every 10 days during constant aqueous exposure at 10, 100, and 1000 µg/L for a total of 40 days, followed by 30 days of depuration. We also examined effects on length and development. PFOS accumulated to the highest levels with whole-body bioconcentration factor (BCF) values at day 40 ranging from 19.6 to 119.3. The other three PFAAs were not found to bioconcentrate (BCF < 1.0 at day 40). Furthermore, some BCF values decreased during the exposure phase, suggesting dilution due to growth and/or changes in toxicokinetics over ontogeny. In depuration studies, half-lives ranged from  Objective 4: Develop technologies that mitigate adverse human and environmental impacts  Oregon, Jenkins: The Evaluation of Methods/models to Improve Pesticide Dietary Risk Assessment in Thailand. This research aims to improve pesticide dietary risk assessment in Thailand. Dietary risk assessment methods and models were evaluated to facilitate a more efficient and accurate dietary exposure assessments in Thailand that support risk managers in their decision making on food safety, including risk assessment of pesticide residues on agricultural commodities at farm level and evaluating results of market basket surveys. Improved dietary risk assessment also supports compliance with the World Trade Organization (WTO) Agreement on the Application of Sanitary and Phytosanitary Measures, which includes the establishment of the national MRLs for pesticides based on the international guidelines; compliance with the WTO SPS is critical to international trade.

Publications

Impact Statements

Judicious use of agrochemicals and other anthropogenic chemicals will demand practical knowledge of their fate and effects in agricultural and natural ecosystems. The directed multi-institutional federal-state and interdisciplinary research efforts combined with state experimental station outreach reported herein facilitates the development and adoption of economic technologies that improve pest management and other endeavors while minimizing adverse human and environmental impacts.

Date of Annual Report: 08/09/2018

Report Information

Annual Meeting Dates: 06/03/2018 - 06/06/2018
Period the Report Covers: 05/01/2017 - 04/30/2018

Participants

Participants
Kevin Armbrust, Louisiana State Agricultural Experiment Station
Jay Gan, California Agricultural Experiment Station
Jeff Jenkins, Oregon State Agricultural Experiment Station
Qing Li, Hawaii Agricultural Experiment Station
Glenn Miller, Nevada Agricultural Experiment Station
Sharon Papiernik, USDA ARS South Dakota
Kathleen Hapeman, USDA ARS Maryland
Marisol Sepulveda, Indiana Agricultural Experiment Station
Chris Pritsos, Nevada Agricultural Experiment Station; W-3045 Administrative Advisor

Brief Summary of Minutes

Minutes Attachment:

W-3045 2018 meeting minutes.docx

Accomplishments

Objective 1: Identify, develop, and/or validate trace residue analytical methods, immunological procedures, and biomarkers  Hawaii, Li: π-Cation Interactions in Molecular Recognition and Design. The π-cation interaction that differs from the cation-π interaction is a valuable concept in molecular design of drugs and pesticides. In this report we present an up-to-date review (1995 to 2017) on bioactive molecules involving π-cation interactions with the recognition site, and categorize into systems of inhibitor-enzyme, ligand-receptor, ligand-transporter, and hapten-antibody. The concept of π-cation interactions offers use of π systems in a small molecule to enhance the binding affinity, specificity, selectivity, lipophilicity, bioavailability, and metabolic stability, which are physiochemical features desired for drugs and pesticides.   California, Gan: A Tiered Framework to Evaluating Accumulation of Emerging Contaminants in Food Crops. Irrigation with treated wastewater and application of biosolids or animal waste introduce numerous contaminants of emerging concern (CECs) into agroecosystems. Accumulation of CECs in food produce constitutes a potential food safety and human health risk. However, a comprehensive risk assessment and management of CECs in agroecosystems is constrained by multiple factors, the utmost of which is the enormous number and diverse characteristics of CECs.  In this perspective, we briefly summarize the current knowledge on accumulation of CECs in plants including vegetables. We then delineate processes contributing to the ultimate accumulation of CECs in edible tissues in the soil-plant continuum. We outline a tiered framework as the path forward to prioritize CECs that may have a high risk for accumulation in food produce. This tiered approach is valuable as it helps us focus our research efforts only on the priority CECs and thus maximizes the use of our limited research resources to tackle this urgent issue.   Objective 2: Characterize abiotic and biotic reaction mechanisms, transformation rates, and fate in agricultural and natural ecosystems   Louisiana, Armbrust: Advanced Experiments to Investigate Pesticide Fate Processes in Shallow Water Aquatic Systems. Shallow water aquatic systems are relevant to many areas in agriculture.  Some agricultural settings, such as rice culture, make use of these directly to control weeds and other agricultural pests.  They are also employed in aquaculture for many marine species (fish, crabs, shrimp) as well as freshwater aquaculture (catfish, crawfish) and can serve as breeding grounds freshwater and marine organisms and serve as breeding grounds for juvenile organisms. The purpose of the present and ongoing investigation is to use shallow irradiated water-sediments systems to simulate degradation processes influenced by sunlight in shallow aquatic habitats such as rice fields and estuarine systems receiving agricultural runoff, hydroxyl radical rate constants to capture degradation rate information for chemicals susceptible to this process, and phototoxicity experiments on freshwater and marine fish as well as an economically important invertebrate, red swamp crawfish.  Many of these processes are not captured in the standard battery of tests submitted by registrants for pesticide registration, but can be captured by these systems and potentially simulated exposure models used by the US EPA.  The present work is focusing on selected rice herbicides as well as the fungicide dicloran.   USDA ARS Maryland, Hapeman: Launching a National Study to Age-date Stream Waters using Chiral MESA. Agricultural activities can be significant non-point sources of nutrient pollution to surface waters, and various conservation practices and remediation methods have been implemented to control and remediate these nutrient losses. Evaluating their effectiveness on mitigating delivery of groundwater pollutants to surface waters requires reliable dating methods to measure groundwater residence times. Several approaches have been utilized to improve these estimates, including isotopic ratio changes in nitrate or water, fortuitous detection of soluble anthropogenic compounds (e.g., CFCs, SF6), or gaseous analysis, but significant uncertainties still exist. Furthermore, these methods cannot be used in waters exposed to atmosphere, such as streams and lakes. Recently, we have discovered a method to estimate the age of groundwater under agricultural lands based on the mean residence time and the change in the chirality ratio of MESA (metolachlor ethane sulfonic acid, 2-[(2-ethyl-6-methylphenyl)(2-methoxy-1-methylethyl)amino]-2-oxoethanesulfonic acid), a degradation product of the herbicide metolachlor (2-chloro-N-(2-ethyl-6-methylphenyl)-N-(1-methoxypropan-2-yl)acetamide).     Objective 3: Determine adverse impacts from agrochemical exposure to cells, organisms, and ecosystems   Indiana, Sepulveda:  Effects of Per/Polyfluoroalkyl Substance (PFAS) Exposure on Larval Eastern Tiger Salamanders (Ambystoma tigrinum) and American Toads (Anaxyrus americanus). Per/polyfluoroalkyl substances (PFASs) are a ubiquitous group of anthropogenic environmental toxicants. Decades of production and use in a variety of applications has led to contamination of surface waters across the globe. Many species of wildlife are exposed to these compounds with unknown effects, though research suggests exposure may result in disruption of thyroid hormone regulation. Since thyroid hormone is a primary driver of amphibian metamorphosis, amphibians may represent a group of at-risk animals due to PFAS exposure. With this in mind, we chronically exposed larval eastern tiger salamanders (Ambystoma tigrinum) and American toads (Anaxyrus americanus) to four different PFASs (perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonate (PFHxS) and 6:2 fluorotelomer sulfonate (6:2 FtS)). First, we determined time to steady-state by conducting a 40-day uptake study and examining body burdens and bioconcentration of PFAS when exposed via contaminated water. A following study examined effects on growth, body condition, and thyroid gland development. For all compounds, uptake was rapid and a steady-state body burden was generally achieved in 10 d or less. Only PFOS showed significant bioconcentration (up to 117.7 at 10 d, all others were <10 throughout exposure). Salamanders in all treatment groups were found to have body condition indices below control levels, with significance for low dose (10 µg/L PFAS in water) PFOA and PFHxS, as well as mid and high-dose (100 and 1000 µg/L) 6:2 FtS. No reductions in growth or body condition were noted for toads. Thyroid gland development was only appreciable in toads at the developmental stages examined; no effects of PFAS exposure were noted on thyroid gland histology. The reduction in body condition of salamanders exposed to low doses of PFASs is of concern and may adversely affect populations of this species in nature.  Objective 4: Develop technologies that mitigate adverse human and environmental impacts   USDA ARS South Dakota, Papiernik: Summer Fertigation of Dairy Slurry Reduces Subsurface Drainage Nitrate Losses Compared to Fall Injection. Leaching of nitrate (NO3-N) from manure-applied cropping systems can represent a substantial route of nitrogen loss to the environment for dairy farms, particularly in fields with artificial subsurface drainage. In this on-farm study, we used a Before/After analysis to assess the effectiveness of summer fertigation with reduced manure rates versus fall injection of dairy slurry in terms of subsequent corn silage yield, corn N removal, soil NO3-N distribution, and NO3-N losses in subsurface tile drainage from a 65-ha field in Minnesota. Here, we present the results for NO3-N losses. Weekly flow-weighted mean NO3-N concentration in tile drainage was lower during fertigation (47.7 mg L-1) than injection (56.8 mg L-1), although mean weekly drainage depth was greater during fertigation (2.3 versus 1.1 mm). Results suggest that summer fertigation with attendant reduction in application rate is a viable method for reducing drainage NO3-N losses without impacting yield of irrigated silage corn in the U.S. Midwest.    Oregon, Jenkins: Probabilistic Methods to Evaluate the Relationship between Chlorpyrifos Use at the Watershed Scale and Impacts on Aquatic Resources. Pesticide surface water monitoring beginning in the early 1990’s has led to the identification of the Zollner Creek watershed, located in the Willamette Valley, OR, one of the most contaminated surface waters in the state of Oregon. Zollner Creek was monitored for pesticides from 1993-2008 by the USGS as part of the National Water Quality Assessment Program (NAWQA). Starting in 2005, the Oregon Department of Environmental Quality (ODEQ) began monitoring in the Zollner Creek watershed as part of the Pesticide Stewardship Partnership (PSP). For this study, a probabilistic approach was used to characterize use practices of the organophosphate insecticide chlorpyrifos in the Zollner Creek watershed located in the Willamette Valley of Oregon between 2010 and 2011. The Soil and Water Assessment Tool (SWAT) was used to simulate the fate and transport of chlorpyrifos applied in the watershed and estimate aqueous exposure concentrations over a continuous 2 year period. The estimated exposure concentrations were used in conjunction with a Tier 1 Daphnia magna theoretical population model to evaluate the effect on population growth dynamics over the 2 year period. Daphnia magna was chosen as a sensitive species within the salmonid food web.

Publications

Journal Articles <ol> <li>Janney, P. K., J. J. Jenkins. 2018. Modeling ecohydrology in the Zollner Creek watershed, Oregon USA – a systems approach to evaluating the impact of agricultural practices on water resources. Submitted to Journal of Environmental Quality.</li> <li>Hall, K. E., K. A. Spokas, B. Gamiz, L. Cox, S. K. Papiernik, and W. C. Koskinen. Glyphosate sorption/desorption on biochars – Interactions of physical and chemical processes. Pest Manag. Sci. 74: 1206-1212. 2017.</li> <li>Sandhu, S. S., D. A. N. Ussiri, S. Kumar, R. Chintala, S. K. Papiernik, D. D. Malo, and T. E. Schumacher. Analyzing the impacts of three types of biochar on soil carbon fractions and physiochemical properties in a corn-soybean rotation. Chemosphere 184:473-481. 2017.</li> <li>Gamble, J. D., G. W. Feyereisen, S. K. Papiernik, C. Wente, and J. Baker. Regression-kriged soil organic carbon stock changes in manured corn silage–alfalfa production systems. Soil Sci. Soc. Am. J. 81:1557-1566. 2017.</li> <li>Gamble, J., G. W. Feyereisen, J. M. Baker, S. K. Papiernik, and C. D. Wente. Summer fertigation of dairy slurry reduces soil nitrate concentrations and subsurface drainage nitrate losses compared to fall injection. Front. Sustain. Food Syst. 2:15. 2018.</li> <li>Papiernik, S. K., T. W. Sappington, R. G. Luttrell, L. S. Hesler, and K. C. Allen. Overview: Risk factors and historic levels of pressure from insect pests of seedling corn, cotton, soybean, and wheat in the U.S. J. Integrated Pest Manag. In press.</li> <li>Sappington, T. W., L. S. Hesler, K. C. Allen, R. G. Luttrell, and S. K. Papiernik. Prevalence of sporatic insect pests of seedline corn and factors affecting risk of infestation. J. Integrated Pest Manag. In press.</li> <li>Hesler, L. S, K. C. Allen, R. G. Luttrell, T. W. Sappington, and S. K. Papiernik. Early-season pests of soybean in the United States and factors that affect their risk of infestation. J. Integrated Pest Manag. In press.</li> <li>Allen, K. C., R. G. Luttrell, T. W. Sappington, L. S. Hesler, and S. K. Papiernik. Frequency and abundance of selected early-season insect pests of cotton. J. Integrated Pest Manag. In press.</li> <li>Wang, ; Peng, J.; Li, Q.X.; Peng, Y-L. 2017. Phosphorylation-mediated regulatory networks in mycelia of Pyricularia oryzae revealed by phosphoproteomic analyses. Molecular and Cellullar Proteomics 16: 1669-1682.</li> <li>Lv,; Zhang, J.; Shi, T.; Dai, L.; Li, X.; Wu, X.; Li, X.; Tang, J.; Li, Q.X.; Hua, R. 2017. Procyanidolic oligomers enhance photodegradation of chlorothalonil in water via reductive dechlorination. Applied Catalysis B: Environmental 217: 137-143.</li> <li>Wang, ; Zhu, M.; Jiang, E.; Hua, R.; Na, R.; Li, Q.X. 2017. A simple and rapid turn on ESIPT fluorescent probe for colorimetric and ratiometric detection of biothiols in living cells. Scientific Reports 7(1):4377.</li> <li>Wu, ; Sun, Z.; Shi, T.; Pan, D.; Xue, J.; Li, Q.X.; Hua, R. 2017. Influence of plant growth regulating substances on transport and degradation of acephate and its metabolite methamidophos in tomato. Int’l J. of Environmental Analytical Chemistry 97(4): 345-354.</li> <li>Wu, ; Xue, J.; Pan, D.; Jin, L.; Shi, T.; Cheng, X.; Li, Q.X.; Hua, R. 2017. Dissipation and residue of acephate and its metabolite metamidophos in peach and pear under field conditions. Int’l J. of Environmental Research 11(2): 133–139.</li> </ol> <ol start="15"> <li>Xie,; Zhao, C.; Han, Q.; Zhou, H.; Li, Q.X.; Diao, X. 2017. Effects of pyrene exposure on immune response and oxidative stress of the pearl oyster, Pinctada martensii. Fish Shellfish Immunol. 63: 237-244.</li> <li>Chen, ; Chen, C.; Yoza, B.A.;· Li, Q.X.;· Guo, S.; Wang, P.; Dong, S.; Wang, Q.H. 2017. Efficient ozonation of reverse osmosis concentrates from petroleum refinery wastewater using composite metal oxide loaded alumina supports. Petroleum Science 14: 605-615.</li> <li>Chen,; Liang, J.; Yoza, B.A.; Li, Q.X.; Zhan, Y.; Wang, Q. 2017. Evaluation of an up- flow anaerobic sludge bed (UASB) reactor containing diatomite and maifanite for the improved treatment of petroleum wastewater. Bioresource Technology 243: 620-627.</li> <li>Wang, ; Boesch, R.; Li, Q.X. 2017. A case study of air quality - pesticides and odorous phytochemicals on Kauai, Hawaii, USA. Chemosphere 189: 143-152.</li> <li>Cho, K.; Park, B.-J.; ·Chung, K.H.; Li,Q.X.; Kan, E. 2017. Fenton oxidation of bisphenol A using an Fe3O4-coatedcarbon nanotube: Understanding of oxidation products, toxicity and estrogenic activity. Korean Journal of Pesticide Science 21(3): 310-315.</li> <li>Ye, ; Ching, T.H.; Yoza, B.A., Masutani, S.; Li, Q.X. 2017. Cometabolic degradation of blended biodiesel by Moniliella wahieum Y12Tand Byssochlamys nivea M1. International Biodeterioration & Biodegradation 125: 166-169.</li> <li>Wang, ; Geng, A.; Dong, Y.; Fu, C.; Li, H.; Zhao, Y.; Li, Q.X.; Wang, F. 2017. Comparison of translocation and transformation from soil to rice and metabolism in rats for four arsenic species. Journal of Agricultural and Food Chemistry 65 (41): 8992–8998.</li> <li>Cao, ; Zhang, W.; Ning, X.; Wang, B.; Liu, Y.; Li, Q.X. 2017. Development of monoclonal antibodies recognizing linear epitope: illustration by three Bacillus thuringiensis crystal proteins of genetically modified cotton, tobacco and maize. Journal of Agricultural and Food Chemistry 65(46): 10115-10122.</li> <li>Pan, ; Li, Q.X.; Lin, Z.; Chen, Z.; Tang, W.; Tan, H.; Pan, C.; Zeng, D. 2017. Interactionsbetween salicylic acid and antioxidant enzymes tilting the balance of H2O2 from photorespiration in nontarget-crops under halosulfuron-methyl stress. Pesticide Biochemistry and Physiology 143: 214-223.</li> <li>Clukey, E.; Lepczyk, C.A.; Balazs, G.H.; Work, T.M.; Li, Q.X.; Bachman, M.J.; Lynch,</li> <li>2018. Persistent organic pollutants in fat of three species of Pacific pelagic longline caught sea turtles: Accumulation in relation to ingested plastic marine debris. Science of the Total Environment 610-611:402-411.</li> <li>Chen, ; Yan, X.; Yoza, B.A; Zhou, T.; Li, Y.; Zhan, Y.; Wang, Q,; Li, Q.X. 2018. Efficiencies and mechanisms of ZSM-5 zeolites loaded with cerium, iron, or manganese oxides for catalytic ozonation of nitrobenzene in water. Science of the Total Environment 612: 1424–1432.</li> <li>Liu,; Pan, D.; Wu, X.; Chen, H.; Cao, H.; Li, Q.X.; Hua, R. 2018. Enhanced degradation of prometryn and other s-triazine herbicides in pure cultures and wastewater by polyvinyl alcohol-sodium alginate immobilized Leucobacter sp. JW-1. Science of the Total Environment 615: 78-86.</li> </ol> <ol start="27"> <li>Li, ; Li, Y.; Pan, X.; Li, Q.X.; Chen, R.; Li,X.; Pan, C.; Song, J. 2018. Comparison of a new air-assisted sprayer and two conventional sprayers in terms of deposition, loss to the soil and residues of azoxystrobin and tebuconazole applied to sunlit greenhouse tomato and field cucumber. Pest Management Science 74(2): 448-455.</li> <li>Sun, ; Pan, D.; Liu, J.; Wu, X.; Hua, R.; Li, Q.X. 2018. Leucobacter prometrynivorans sp. nov., a prometryn-degrading bacterium isolated from sludge. International Journal of Systematic and Evolutionary Microbiology 68: 204-210.</li> <li>Islam, ; Wang, J.; Farooq, M.A.; Khan, M.S.S.; Xu, L.; Zhu, J.; Zhao, M.; Muños, S.; Li, Q.X.; Zhou, W. 2018. Potential impact of the herbicide 2,4-dichlorophenoxyacetic acid on human and ecosystems. Environmental International 111: 332-351.</li> <li>Lv, ; Chen, Y.; Zhao, Z.; Shi, T.; Wu, X.; Li, Q.X.; Hua, R. 2018. Design, synthesis and antifungal activities of 3-acyl thiotetronic acid derivatives: New fatty acid synthase inhibitors. Journal of Agricutlrual and Food Chemistry 66(4): 1023–1032.</li> <li>Fu, ; Xu, T.; Cui, Z.; Ng, Ho, L.; Wang, K.; Li, J.; Li, Q.X. 2018. Mutation of phenylalanine-223 to leucine enhances transformation of benzo[a]pyrene by ring- hydroxylating dioxygenase of Sphingobium sp. FB3 by increasing accessibility of the catalytic site. Journal of Agricultural and Food Chemistry 66(5): 1206-1213.</li> <li>Zhang, ; Zhou, L.; Li, Q.X.; Liang, H.; Qin, H.; Masutani, S.; Yozae, B. 2018. Toxicity of lanthanum oxide nanoparticles to the fungus Moniliella wahieum Y12T isolated from biodiesel. Chemosphere 199: 495-501.</li> <li>Chu, ; Baker, M.R.; Leong, G.; Letcher, R.J.; Li, Q.X. 2018. Covalent binding of the organophosphate insecticide profenofos to tyrosine on α- and β-tubulin proteins. Chemosphere 199: 154-159.</li> <li>Wang, ; Ma, W.; Yoza, B.A.; Xu, Y.; Li, Q.X.; Chen, C.; Wang, Q.; Gao, Y.; Guo, S.; Zhan, Y. 2018. Investigation of catalytic ozonation of recalcitrant organic chemicals in aqueous solution over various ZSM-5 zeolites. Catalysts 8(4): 128.</li> <li>Sanchis, ; Salvador, J.-P.; Campbell, K.; Elliott, C.T.; Shelver, W.L.; Li, Q.X.; Marco, M.-</li> <li>2018. Fluorescent Microarray for Multiplexed Quantification of Environmental Contaminants in Seawater Samples. Talanta 184: 499-506.</li> <li>Wang, ; Liu, J.; Zhu, M.; Wang, L.; Zen, X.; Fan, S.; Wang, Z.; Li, H.; Na, R.; Zhao, X.; Li, Q.X. 2018. Biophysical characterization of interactions between falcarinol-type polyacetylenes and human serum albumin via multispectroscopy and molecular docking techniques. Journal of Luminescence 200: 111-119.</li> <li>Chen,; Xianyang Yao, C.; Li, Q.X.; Wang, Q.; Liang, J.; Zhang, S.; Ming, J.; Liu, Z.; Deng, J.; Yoza, B.A. 2018. Turf soil enhanced treatment of phenolic wastewater using an up-flow anaerobic sludge blanket (UASB) reactor. Chemosphere 204: 227-234.</li> <li>Wang, ; Na, R.; Zhu, M.; Jiang, E.; Wang, L.; Fan, S.; Wang, Z.; Li, Q.X.; Hua, R. 2018. A colorimetric and ratiometric dual-site fluorescent probe with 2,4-dinitrobenzenesulfonyl aldehyde groups for imaging of aminothiols in living cells and zebrafish. Dyes and Pigments 156: 338-347.</li> </ol> <ol start="39"> <li>Nzila, ; Ortega Ramirez, C.; Musac, M.M.; Sankaraa, S.; Chanbashac, B.; Li, Q.X. 2018. Pyrene biodegradation and proteomic analysis in Achromobacter xylosoxidans, PY4 strain. International Biodeterioration & Biodegradation 130: 40-47.</li> <li>Fu, Q.G., Q.F. Ye, J. Richards, and J. Gan. 2017. Metabolism of diclofenac in Arabidopsis thaliana cells: Dominance of conjugates and non-extractable residues. Environmental Pollution 222: 383-392.</li> <li>Lao, W.J., Y.W. Hong, D. Tsukada, K. Maruya, and J. Gan. 2016. A new film-based passive sampler for moderately hydrophobic organic compounds. Environmental Science & Technology 50: 13470-13476.</li> <li>Liao, C.Y., A.R. Taylor, W.F. Kenney, M. Brenner, D. Schlenk, and J. Gan. 2017. Historical record and fluxes of DDTs and PCBs at the Palos Verdes Shelf Superfund site, California. Science of the Total Environment 581-582: 697-704.</li> <li>Lin, K.D., W.J. Lao, Z.J. Lu, F. Jia, K. Maruya, and J. Gan. 2017. Measuring freely dissolved DDT and metabolites in seawater using solid-phase microextraction with performance reference compounds. Science of the Total Environment 599-600: 364-371.</li> <li>Xue, J.Y., C.Y. Liao, J. Wang, Z. Cryder, T.B. Xu, F.M Liu, and J. Gan. Development of passive samplers for in situ measurement of pyrethroid insecticides in surface water. Environmental Pollution 224: 516-523.</li> <li>Fu, Q.G., J.B. Zhang, Schlenk, D. Borchardt, and J. Gan. 2017. Direct conjugation of emerging contaminants in higher plants: An overlooked risk? Environmental Science & Technology 51: 6071-6081.</li> <li>Coffin, S., J. Gan, and D. Schlenk. 2017. The use of an isotope dilution method to estimate risk of DDTs from contaminated sediments to humans that consume fish in Palos Verdes, California, USA. Science of the Total Environment 601-602: 1139-1146.</li> <li>Ding, T.D., M.T. Yang, J.M. Zhang, K.D. Lin, J.Y. Li, and J. Gan. 2017. Toxicity, degradation and metabolic fate of ibuprofen on freshwater diatom Navicula sp. Journal of Hazardous Materials 330: 127–134.</li> <li>Cheng, Z.P., F.S. Dong, J. Xu, X.G. Liu, X.H. Wu, Z.L. Chen, X.L. Pan, J. Gan, Y.Q. Zheng. 2017. Simultaneous determination of organophosphorus pesticides in fruits and vegetables using atmospheric pressure gas chromatography quadrupole-time-of-flight mass spectrometry. Food Chemistry 231: 365–373.</li> <li>Pennington, M.J., J.A. Rothman, M.B. Jones, Q.S. McFrederick, J. Gan, and J.T. Trumble. 2017. Effects of contaminants of emerging concern on Megaselia scalaris (Lowe, Diptera: Phoridae) and its Microbial Community. Scientific Reports 7: 8165, DOI:10.1038/s41598-017-08683-7</li> <li>Ding, T.D., K.D. Lin, B. Yang, M.T. Yang , J.Y. Li, W.Y. Li, and J. Gan. 2017. Biodegradation of naproxen by freshwater algae Cymbella and Scenedesmus quadricauda and the comparative toxicity. Bioresource Technology 238: 164-173.</li> <li>Sanganyado, E., Z.J. Lu, Q.G. Fu, D. Schlenk, and J. Gan. 2017. Chiral pharmaceuticals: A review on their environmental occurrence and fate processes. Water research 124: 527-542.</li> <li>Bertotto, L., J. Richards, J Gan, D. Volz, and D. Schlenk. 2018. Effects of bifenthrin exposure on the estrogenic and dopaminergic pathways in zebrafish embryos and juveniles. Environmental Toxicology & Chemistry 37: 236-246.</li> <li>Liao, C.Y., J. Richards, A. Taylor, and J. Gan. 2017. Development of polyurethane-based passive samplers for ambient monitoring of urban-use insecticides in water. Environmental Pollution 231: 1412-1420</li> <li>Sun, C.L., S. Dudley, and J. Gan. 2018. Pharmaceutical and personal care products-induced stress symptoms and detoxification mechanisms in cucumber plants. Environmental Pollution 234: 39-47.</li> <li>Pennington, M.J., J.A. Rothman, S. L. Dudley, M. B. Jones, Q. S. McFrederick, J. Gan, and J. T. Trumble. 2017. Contaminants of emerging concern affect Trichoplusia ni growth and development on artificial diets and a key host plant. Proceedings of National Academy of Science USA. 9923–9931 (<a href="http://www.pnas.org/cgi/doi/10.1073/pnas.1713385114">pnas.org/cgi/doi/10.1073/pnas.1713385114</a>)</li> <li>Ding, T.D., K.D. Lin, M.T. Yang, L.J. Bao, J.Y. Li, B. Yang, and J. Gan. Biodegradation of triclosan in diatom Naviculasp.: Kinetics, transformation products, toxicity evaluation and the effects of pH and potassium permanganate. Journal of Hazardous Materials 344: 200-209.</li> <li>Richards, J., Z.J. Lu, Q.G. Fu, D. Schlenk, and J. Gan. Conversion of pyrethroid insecticides to 3-phenoxybenzoic acid on urban hard surfaces. Environmental Science & Technology Letters 4: 546-550.</li> <li>Wang, J., A. Taylor, C.Y. Xu, D. Schlenk, and J. Gan. 2018. Evaluation of different methods for assessing bioavailability of DDT residues during soil remediation. Environmental Pollution 238: 462-470.</li> <li>Wang, J., A. Taylor, D. Schlenk, and J. Gan. 2018. Development of isotope dilution method (IDM) for predicting bioavailability of hydrophobic organic pollutants in soil. Environmental Pollution 236: 871-877.</li> <li>Fu, Q.G., C.Y. Liao, D. Schlenk, and J. Gan. 2018. Back conversion from product to parent: Methyl triclosan to triclosan in plants. Environmental Science & Technology Letters 5: 181-185.</li> <li>Pennington, M., J.A. Rothman, M.B. Jones, Q.S McFrederick, J. Gan, and J.T. Trumble. 2018. Effects of contaminants of emerging concern on Myzus persicae (Sulzer, Hemiptera: Aphididae) biology and on their host plant, Capsicum annum. Environmental Monitoring and Assessment 190: 125 (1-11).</li> <li>Ding, T.D., K.D. Lin, L.J. Bao, M.T. Yang, J.Y. Li, B. Yang, and J. Gan. 2018. Biouptake, toxicity and biotransformation of triclosan in diatom Cymbella sp. and the influence of humic acid. Environmental Pollution 234: 231-242.</li> <li>Sun, C.L., S. Dudley, M. McGinnis, and J. Gan. Hydrogen peroxide mediated root growth inhibition in wheat by triclosan. Environmental Pollution (in press)</li> <li>Wang, J., K.D. Lin, A. Taylor, and J. Gan. In vitro Assessment of pyrethroid bioaccessibility via particle ingestion. Environment International (in press).</li> <li>Zhai, Y.W., X.H. Xia, X.Y. Xiong, L.Z. Xia, X.J. Guo, and J. Gan. 2018. Role of fluoranthene and pyrene associated with suspended particles in their bioaccumulation by zebrafish (Danio rerio). Ecotoxicology and Environmental Safety 157: 89-94.</li> <li>Ding, T.D., K.D. Lin, J. Chen, Q. Hu, B. Yang, J.Y. Li, and J. Gan. 2018. Causes and mechanisms on the toxicity of layered double hydroxide (LDH) to green algae Scenedesmus quadricauda. Science of the Total Environment 635: 1004-1011. Romero-Flores, McConnell LL, Hapeman CJ, Ramirez M, Torrents A. 2017. Evaluation of an electronic nose for improved biosolids alkaline-stabilization treatment and odor management. Chemosphere 186:151-159.</li> <li>Niño de Guzmán GT, Hapeman CJ, Millner PD, McConnell LL, Jackson D, Kindig D, Kjellerup B, Torrents A. 2018. Using a high-organic matter biowall to treat a trichloroethylene plume at the Beaver Dam Road Landfill. Environ Sci Pollut Res 25:8735-8746.</li> <li>Spiegal S, Bestelmeyer BT, Archer DW, Augustine DJ, Boughton EH, Boughton RK, Cavigelli MA, Clark PE, Derner JD, Duncan EW, Hapeman CJ, Harmel RD, Heilman P, Holly MA, Huggins DR, King K, Kleinman PJA, Liebig MA, Locke MA, McCarty GW, Millar N, Mirsky SB, Moorman TB, Pierson FB, Rigby JR, Robertson GP, Steiner JL, Strickland TC, Swain HM, Wienhold BJ, Wulfhorst JD, Yost MA, Walthall CL. 2018. Sustainable intensification of U.S. agriculture: strategies, barriers, and the role of the Long-Term Agroecosystem Research network. Environ Res Lett 13:034031. DOI: https:10.1088/1748-9326/aaa779.</li> <li>Yao Q, Yang Z, Li H, Buser MD, Wanjura JD, Downey PM, Zhang C, Craige C, Torrents A, McConnell LL, Holt GA, Hapeman CJ. 2018. Assessment of particulate matter and ammonia emission concentrations and respective plume profiles from a commercial poultry house. Env Pollut 238:10-16.</li> <li>Ro KS, Li H, Hapeman CJ, Harper LA, Flesch TK, Downey PM, McConnell LL, Torrents A, Yao Q. 2018. Enhanced dispersion and removal of ammonia emitted from a poultry house using a vegetative environmental buffer. Agriculture 8:46. DOI:10.3390/agriculture8040046.</li> </ol> <ol> <li>Abdel-moneim A, Mahapatra CT*, Sepúlveda MS. (2018). In vivo visual reporter system for estrogenic contaminant exposure using transgenic see-through Japanese medaka Oryzias latipes. Chemosphere 201:251-253. (IF = 4.20).</li> <li>Rodgers ML, Jones ER, Klinkhamer C, Mahapatra CT*, Serafin J, Bosker T, Perkins C, Griffitt RJ, De Guise S, Sepúlveda MS. (2018). Combined effects of Deepwater Horizon crude oil and environmental stressors on Fundulus grandis embryos. Environmental Toxicology and Chemistry. In Press. (IF = 2.95).</li> <li>Poynton HC, Hasenbein S, Benoit JB, Sepúlveda MS, Poelchau MF, Hughes DST, Murali SC, Chen S, et al. (2018). The Toxicogenome of Hyalella azteca: a model for sediment ecotoxicology and evolutionary toxicology. Environmental Science & Technology. In Press. (IF = 6.19).</li> <li>Godfrey A, Hooser B, Abdel-moneim A, Horzmann KA, Freeman JL, Sepúlveda MS. (2017) Thyroid disrupting effects of halogenated and next generation chemicals on the swim bladder development of zebrafish. Aquatic Toxicology 193:228-235. (IF = 4.12).</li> <li>Thurner K, Goforth RR, Chen S, Amberg J, Leis E, Kinsella JM, Mahapatra C, Sepúlveda MS. (2017) Viruses, bacteria and helminths of invasive carp: Insights from an in vitro assay and a survey with native fishes in a large Midwestern River. Journal of Fish Pathology 30:000-000. (IF = 2.05).</li> <li>Chatuverdi P, Vanegas DC, Hauser BA, Foster JS, Sepúlveda MS, McLamore ES (2017) Microprofiling real time nitric oxide flux for field studies using a stratified nanohybrid carbon-metal electrode. Analytical Methods 42:6061-6072. (IF = 1.90).</li> <li>Hoover GM, Chislock MF*, Tornabene BJ, Guffey SC, Choi YJ, De Perre C, Hoverman JT, Lee LS, Sepúlveda MS. (2017). Uptake and depuration of four per/polyfluoroalkyl substances (PFASs) in northern leopard frog Rana pipiens tadpoles. Environmental Science & Technology Letters 4:399-403. (IF = 5.30).</li> <li>Abdel-moneim A, Deegan D, Gao J, Perre C, Doucette JS, Jenkinson B, Lee LS,  Sepúlveda MS. (2017) Gonadal intersex in smallmouth bass Micropterus dolomieu from northern Indiana with correlations to molecular biomarkers and anthropogenic chemicals. Environmental Pollution 230:1099-1107. (IF = 5.09).</li> <li>Bosker T, van Balen Liselotte, Walsh B, Sepúlveda MS, DeGuise S, Perkins C, Griffitt R. (2017). The combined effect of Macondo oil and corexit on sheepshead minnow (Cyprinodon variegatus) during early development. Journal of Toxicology and Environmental Health Part A 80:477-484. (IF = 2.73).</li> <li>Godfrey A, Abdel-moneim A, Sepúlveda MS. (2017) Acute mixture toxicity of halogenated chemicals and their next generation counterparts on zebrafish embryos. Chemosphere 181:710-712. (IF = 4.20).</li> <li>Dunlop ES, McLaughlin R, Adams JV, Jones M, Birceanu O, Christie MR, Criger LA, Hinderer JLM, Hollingworth RM, Johnson NS, Lantz S, Li W, Mille J, Morrison BJ, Mota-Sanchez D, Muir A, Sepúlveda MS, Steeves T, Walter L, Westman E, Wirgin I, Wilkie MP. (2017) Rapid evolution meets invasive species control: the potential for pesticide resistance in sea l. Canadian Journal of Fisheries and Aquatic Sciences 75:152-168. (IF = 2.85).</li> <li>Keller CEM, Sepúlveda MS, Hopf Jannasch A, Roumani AM, Zhou FC, Brown PB. (2017) Metabolite changes in the zebrafish model of fetal alcohol spectrum disorder associated with established neural abnormalities. The FASEB J. 31:792.1. (IF = 5.49).</li> <li>Miles JC, Hua J, Sepúlveda MS, Krupke CH, Hoverman JT. (2017). Effects of clothianidin on aquatic communities: Evaluating the impacts of lethal and sublethal exposure to neonicotinoids. PLoS ONE 12, e0174171. (IF = 3.23).</li> <li>Almeida LZ, Guffey SC, Sepúlveda MS, Höök TO. (2017) Behavioral and physiological responses of yellow perch (Perca flavescens) to moderate hypoxia. Comparative Biochemistry and Physiology. Part B: Biochemistry and Molecular Biology 209:47-55. (IF = 1.75).</li> <li>Kar S, Sepúlveda MS, Roy K, Leszczynski J. (2017) Endocrine-disrupting activity of per- and polyfluoroalkyl substances: Exploring combined approaches of ligand and structure based modeling. Chemosphere 184:514-523. (IF = 4.20).</li> <li>Mahapatra CT*, Damayanti NP, Guffey SC, Serafin SS, Irudayaraj J, Sepúlveda MS. (2017) Comparative in vitro toxicity assessment of perfluorinated carboxylic acids. Journal of Applied Toxicology 37:699-708. (IF = 3.15).</li> <li>Gao J, Lin L, Wei A, Sepúlveda MS. (2017) Protein corona analysis of silver nanoparticles exposed to fish plasma. Environmental Science & Technology Letters 4:174-179. (IF = 5.30).</li> </ol> <ol start="88"> <li>Estes, T. and Armbrust. (2018).  Development of a New Method for Estimating Runoff Curve Numbers.  Journal of Environmental Quality.  (submitted)</li> <li>Xu, W.; E. Vebrosky, M. Richards and Armbrust (2018). Evaluation of Dicloran Phototoxicity using primary cardiomyocyte culture from Crassostrea virginica.  Science of the Total Environment 628-629:1-10.</li> <li>Vebrosky, E.; Saranjampour, P; D.G. Crosby and Armbrust. (2018). Photodegradation of Dicloran in Freshwater and Seawater.  Journal of Agricultural and Food Chemistry.  66(11):2654-2659.</li> <li>Saranjampour, P; E. Armbrust. (2018). Repeatability of n-octanol/water partition coefficient values between liquid chromatography measurement methods.  Environmental Science and Pollution Research DOI: 10.1007/s11356-018-1729-4.</li> <li>Saranjampour, P; E. Vebrosky and Armbrust. (2017). Salinity impacts on water solubility and n-octanol/water partition coefficients of selected pesticides and oil constituents.  Environmental Toxicology and Chemistry 36(9): 2274-2280.</li> <li>Sarajampour, P., Armbrust and BD. Marx. (2017).  Assessing the hydroxyl radical and volatilization roles in the aquatic fate of polycyclic aromatic sulfur-containing hydrocarbons.  Environmental Toxicology and Chemistry 36(8):1998-2004.</li> </ol>

Impact Statements

1. Judicious use of agrochemicals and other anthropogenic chemicals will demand practical knowledge of their fate and effects in agricultural and natural ecosystems. The directed multi-institutional federal-state and interdisciplinary research efforts combined with state experimental station outreach reported herein facilitates the development and adoption of economic technologies that improve pest management and other endeavors while minimizing adverse human and environmental impacts.

Date of Annual Report: 07/17/2019

Report Information

Annual Meeting Dates: 06/02/2019 - 06/05/2019
Period the Report Covers: 05/01/2018 - 04/30/2019

Participants

Kevin Armbrust, Louisiana State Agricultural Experiment Station
Laura Basirico, Louisiana State Agricultural Experiment Station
Susanne Brander, Oregon State Agricultural Experiment Station
Joanna Burger, Rutgers University
Jay Gan, California Agricultural Experiment Station
Jeff Jenkins, Oregon State Agricultural Experiment Station
Qing Li, Hawaii Agricultural Experiment Station
Laura McConnell, Bayer CropScience
Fred Michel, Ohio State Agricultural Research and Development Center
Glenn Miller, Nevada Agricultural Experiment Station
Gary Robbins, University of Connecticut
Ruijun Qin, Oregon State Agricultural Experiment Station
Daniel D. Snow, Nebraska Agricultural Experiment Station
Tracy Sterling, Montana Agricultural Experiment Station
Chris Pritsos, Nevada Agricultural Experiment Station; W-3045 Administrative Advisor

Brief Summary of Minutes

Minutes Attachment:

W-3045 2019 meeting minutes.docx

Accomplishments

Accomplishments   Objective 1:  Characterize abiotic and biotic reaction mechanisms, transformation rates, and fate in agricultural and natural ecosystems.   Lousiana, Amrbrust. Shallow water aquatic systems are relevant to many areas in agriculture.  Some agricultural settings, such as rice culture, make use of these directly to control weeds and other agricultural pests.  They are also employed in aquaculture for many marine species (fish, crabs, shrimp) as well as freshwater aquaculture (catfish, crawfish) and can serve as breeding grounds freshwater and marine organisms and serve as breeding grounds for juvenile organisms.  Intertidal estuarine systems at the terminus of agricultural watersheds and near shore waterbodies receiving agricultural runoff are also relevant habitats.  Environmental fate processes that occur within these areas may dominate in comparison to processes in deeper water bodies.  For example, photochemical processes will be more dominant in shallow water versus deeper water bodies where light is more strongly attenuated.  Additionally, photochemical processes at sediment-water interfaces can become significant in these ecosystems and can include not only degradation through direct photochemical processes but also indirect processes at the interface or thought radical oxidants generated at the interface.  Additionally organisms that live within these habitats may be more susceptible to photochemically induced toxicity.  This may occur through direct absorption of a chemical from the water or, for epibenthic organisms, exposure to the pore water at the sediment water interface.  The purpose of the present and ongoing investigation was to apply shallow irradiated water-sediments systems to simulate degradation processes influenced by sunlight in shallow aquatic habitats to the new rice herbicide Benzobicylon (RougeÒ) and measure its degradation in rice field settings.  Results from this work can assist growers with dissipation information under local conditions as well as provide data allowing more informed exposure assessments by the US EPA.   Montana, Sterling. Smooth brome volatiles may help trap a major insect pest of wheat. Smooth brome (Bromus inermis Leyss.) is a cool-season, perennial grass that spreads by rhizomes and was introduced in the 1880s as a livestock forage and for erosion control; it grows across North America along most highways and many times in proximity to wheat-growing regions, and is considered weedy in some habitats.  The major wheat pest, wheat stem sawfly (Cephus cinctus Norton) (WSS) causes $350 million of annual damage in wheat fields throughout the Northern Great Plains. Insecticides are not effective in this pest system, but smooth brome may be an alternate host and serve as a perimeter trap. No data exist to demonstrate its effectiveness; therefore, we investigated host preference behaviors of WSS between plants at two growth stages in laboratory and greenhouse conditions and identified and quantified attractive volatile compounds from wheat and smooth brome using GC-MS. In Y- tube olfactometer bioassay, WSS were more attracted towards the volatiles emitted from bromes compared to wheat. Furthermore, the duration of oviposition insertion along with the length of time spent on stem, leaves, oviposition insertions, and quiescence was higher in brome as compared to wheat (data not shown). There were more eggs per stem in bromes than in wheat. Consistent with these behaviors, we found significant differences in some volatile compounds collected from both plant species among which some of them have been suggested as behaviorally active compound for female WSS. With more egg loads and more larval mortality in premature stages of plants, less cut stems and significantly higher amount of behaviorally active volatile compounds, smooth bromes could potentially be used to improve integrated pest management strategies for WSS.   Objectives: 1. Characterize abiotic and biotic reaction mechanisms, transformation rates, and fate in agricultural and natural ecosystems, and 2. Determine adverse impacts from agrochemical exposure to cells, organisms, and ecosystems.   Ohio, Michal. Phragmites Composting: Optimization of Compost Amendment Ratio and Determination of Seed and Glyphosate Persistence. Phragmites (Phragmites australis subspecies australis) is an invasive, non-native reed grass that has inundated natural areas of Ohio and the United States. Certain natural and restored areas along the Black River near Lorain, Ohio have become overgrown with Phragmites over many years. Phragmites is one of the fastest growing and most invasive grass species. Controlling Phragmites infestations usually requires multiple herbicide applications during the spring or summer after panicle formation (Mozdzer et al., 2008), followed by cutting the plants at ground level for disposal. The herbicide used to kill Phragmites is Aqua-net, an aquatic glyphosate with a non-ionic surfactant. Glyphosate containing herbicides are widely used and also known by the trade names Rodeo, Roundup and Shore Klear. A question that has been raised concerning the use of these herbicides is whether they would persist and be present at phytotoxic concentrations in composts produced from treated Phragmites residues. This is of concern since nearly all of the Phragmites removed from the site may have received a lethal dose of glyphosate.   Nebraska, Snow. Mechanisms, mitigation and uptake of geogenic contaminants in ephemerally irrigated crops. This four-year study is focused on transfer of arsenic, uranium and selenium from soil or irrigation water to food and feed crops and will improve our understanding of the fate of these chemicals in the environment as well as their impacts to humans and animals. Results to date help characterize conditions under which uranium, selenium and arsenic is taken up from irrigation water at different stages of plant development.  Field sites in western and central Nebraska have been monitored using soil cores, lysimeters and plant tissue samples over a two growing seasons.  One growing season of greenhouse experiments designed to test the importance of ferrihydrite suggests that transformation and redox cycling of iron oxyhydroxides is one of the key processes affecting mobility and bioavailability of these elements. Crop uptake of arsenic, uranium and selenium is correlated with mobile forms of these elements in soil porewater.   Objectives: 1. Characterize abiotic and biotic reaction mechanisms, transformation rates, and fate in agricultural and natural ecosystems, 2. Determine adverse impacts from agrochemical exposure to cells, organisms, and ecosystems, and 3. Develop technologies that mitigate adverse human and environmental impacts.   Oregon, Jenkins. Probabilistic Methods to Investigate the Fate of Chlorpyrifos and Chlorpyrifos-oxon at the Watershed Scale. Pacific Northwest freshwater resources are key elements in the life history and ecology of Pacific salmon and steelhead (Oncorhynchus sp.). In addition to overfishing, critical habit degradation and loss has been identified as contributing to population decline, resulting in 28 evolutionarily significant units (ESUs) listed as threatened or endangered under the Endangered Species Act (ESA). Characterizing risks to Pacific salmonids and their food web related to pesticide exposure requires complex spatial and temporal information on life history and ecology, as well as pesticide use patterns and environmental fate. For this study, a probabilistic approach is used to characterize use practices of the organophosphate insecticide chlorpyrifos in the Zollner Creek watershed located in the Willamette Valley of Oregon between 2010 and 2011. The Soil and Water Assessment Tool (SWAT) will be used to simulate the fate and transport of chlorpyrifos and its oxon degradate in the watershed in order to estimate aqueous exposure concentrations over a continuous 2 year period.   California, Gan. A Novel Water-Swelling Sampling Probe for in vivo Detection of Neonicotinoids in Plants. Neonicotinoids have rapidly become one of the most commonly used insecticides since their initial introduction in 1990s. The extensive use of neonicotinoids has led to increasing concerns over their adverse ecological implications. Of these concerns, the worldwide crisis of pollinator colonies is regarded as the most urgent. Even though there has been extensive research on the potential role of neonicotinoids in pollinator population declines, limitations in sampling and analytical techniques are preventing a mechanistic understanding to directly connect exposure to the adverse consequence. Most studies to date rely on correlation of the presence of neonicotinoid residues in plant materials with toxicity effects in exposed pollinators or their communities. Conventional analytical methods operate on the principle of exhaustive extraction and analysis of total chemical concentrations. The uptake and translocation of systemic pesticides such as neonicotinoids in plants is via the transpiration stream in xylem, while their distribution in sugars occurs through phloem. Therefore, for pollinators, quantification of neonicotinoids in nectar and sap of flowering plants would improve the estimation of chemical exposure. We developed a sensitive biomimetic SPME fiber for detecting seven neonicotinoids in live plants. The fiber was fabricated by assembling water-swelling crosslinked polyvinyl-pyrrolidone particles on a stainless-steel wire via a simple dip-coating step, and the surface coating was then modified by oxidative self-polymerization of norepinephrine to obtain biocompatible and anti-fouling properties. We demonstrated that the in vivo SPME probe provided nearly instantaneous measurement of neonicotinoids in sap, and that when coupled with the analysis of total tissue concentrations, offered insights on the distribution of neonicotinoids between plant sap and tissue matter.   Objectives: 3. Determine adverse impacts from agrochemical exposure to cells, organisms, and ecosystems, and 4. Develop technologies that mitigate adverse human and environmental impacts.   Hawaii, Li. Putative mode of action of the monoterpenoids linalool, estragole, methyl eugenol and citronellal on ligand-gated ion channels. Essential oils have been used as sedatives, anticonvulsants and local anesthetics in traditional medical remedies; preservatives for food, fruit, vegetable; and grain storage and bio-pesticides for food production. Linalool, along with a few other major components such as estragole, methyl eugenol and citronellal, are the active chemicals in many essential oils, particularly basil oils. Basil oil and aforementioned monoterpenoids are potent against insect pests. However, the molecular mechanism of action of those chemical constituents is not well-understood.  It is well-known that the γ-aminobutyric acid type A receptors (GABAAR) and nicotinic acetylcholine receptor (nAChR) are primary molecular targets of synthetic insecticides used in the market today. Furthermore, GABAAR-targeted therapeutics have been in clinical use for many decades, including barbiturates and benzodiazepines to name a few. Here, we studied the electrophysiological effects of linalool, estragole, methyl eugenol, and citronellal on GABAAR and nAChR to further understand their versatility as therapeutic agents in traditional remedies and as insecticides.  Our results revealed that linalool inhibits both GABAAR and nAChR, which may explain its insecticidal activity. Linalool is a concentration-dependent, non-competitive inhibitor on the GABAAR as the EC50 values of GABA for the rat α1β3γ2L GABAAR were not affected by linalool:  36.2 ± 7.9 µM and 36.1 ± 23.8 µM in the absence and presence of 5 mM linalool, respectively. The half maximal inhibitory concentration (IC50) of linalool on the GABAAR is approximately 3.2 mM. Considering that multiple monoterpenoids are found within the same essential oil, it is likely that linalool has a synergistic effect with methyl eugenol characterized previously as both a GABAAR agonist and positive allosteric modulator and other monoterpenoids, thus offering a possible explanation for its sedative and anticonvulsant effects.

Publications

Impact Statements

W-3045 researchers at Louisiana State University are investigating impacts of herbicide use on irradiated water-sediments systems to simulate degradation processes influenced by sunlight in shallow aquatic habitats to the new rice herbicide Benzobicylon (Rouge) and measure its degradation in rice field settings. Results from this work promise to assist growers with dissipation information under local conditions as well as provide data allowing more informed exposure assessments by the US EPA. Pesticide surface water monitoring beginning in the early 1990’s has led to the identification of the Zollner Creek watershed, located in the Willamette Valley, OR, one of the most contaminated surface waters in the state of Oregon. Zollner Creek has been monitored for pesticides since 1993 by the USGS as part of the National Water Quality Assessment Program (NAWQA). W-3025 researchers at Oregon State University are applying the Soil and Water Assessment Tool (SWAT) to assist producers in the rapid evaluation of mitigation measures by facilitating a systems approach to the understanding of watershed scale pesticide and degrade fate and impact on aquatic resources. Composting is being increasingly called upon as a process to recycle organic wastes (yard trimmings. garden waste, food waste, manure, etc). This is because composting can recover plant nutrients, reduce greenhouse gas emissions from landfills and generate soil amendments that improve soil fertility. However, herbicide contaminated composts have the potential to cause substantial economic damage especially when used by organic producers who can lose certification. Compost producers also can suffer financial setbacks due to claims for damaged gardens and landscaping. The societal impacts are also great since negative perceptions about composts could lead to a reduction in the use of composting as an organics recycling option. W-3045 researchers at Ohio State University are conducting experiments using a compost reactor system to determine whether composting reduces the phytotoxicity of feedstocks treated with glyphosate (Roundup), the most commonly used herbicide. Reactor studies showed that glyphosate treated Phragmites results in phytotoxic composts only when composted alone, and not when mixed with untreated yard trimmings prior to composting. Better understanding of herbicide persistence in feedstocks, their dissipation during composting could lead to improved procedures and labeling, restrictions on the application of persistent herbicides, the development of less recalcitrant herbicides, and mitigation strategies to treat contaminated composts. The major pathway for exposure of terrestrial life to inorganic contaminants in soil is through food ingestion. Rapidly increasing population and living standard has resulted in a significant pressure to increase agricultural production from limited resources while at the same time make food safer for consumption. Soil and irrigation water used for crop production in many areas contains elevated levels of geogenic contaminants such as arsenic, cadmium, chromium, and uranium. Edible plants and crops are known to accumulate these trace elements leading to toxic exposure, and are associated with the presence of high level of contaminants in soils and irrigation waters. W-3045 researchers at the University of Nebraska are conducting a 4-year study to look closely at mobilization and transfer of natural arsenic, uranium and selenium from soil or irrigation water to food and feed crops, which to date have not been well studied. The knowledge gained will greatly improve our understanding of the fate of geogenic contaminants as well as their potential impacts to the health of humans and animals, supporting one of the key goals of United States Department of Agriculture (USDA), which is to “provide all Americans access to a safe, nutritious and secure food supply.” Wheat Stem Sawfly (WSS) is a major wheat pest across the Northern Great Plains causing millions of dollars of losses from wheat yield reductions. W-3045 researchers at Montana State University are conducting lab and field studies to evaluate the potential role of a common perennial grass, smooth brome, in trapping this insect pest. Results show that smooth brome produces the same volatile attractants that wheat does and at higher levels; smooth brome stems also host more larvae than wheat stems. These results suggest that smooth bromes could potentially be used to improve integrated pest management strategies for WSS. Ecotoxicological risks of neonicotinoid insecticides are raising significant concerns, including their potential role in bee population declines. Neonicotinoids are water soluble, systemic insecticides, and exposure of non-target organisms such as pollinators occurs mainly through residues in nectar and pollens of flowering plants. W-3045 researchers at the University of California – Riverside have developed a novel biomimetic water-swelling solid-phase microextraction (SPME) probe with limits of detection for neonicotinoids as low as 0.03 ng mL-1, and applied it for in vivo detection of seven neonicotinoids in plant sap. This novel application of SPME supports in vivo plant assays providing a wealth of information, including changes in levels and distribution of neonicotinoids over time in the same plants. Kinetics and distribution patterns suggested that after treatment at the same level, neonicotinoids differed significantly in their levels in the sap. The in vivo sampling and monitoring of neonicotinoids in live plants may provide unique and much needed information in achieving breakthrough understanding of the connection between neonicotinoid use and pollinator exposure. Essential oils have been used as sedatives, anticonvulsants and local anesthetics in traditional medical remedies; preservatives for food, fruit, vegetable; and grain storage and bio-pesticides for food production. Linalool, along with a few other major components such as estragole, methyl eugenol and citronellal, are the active chemicals in many essential oils, particularly basil oils. Basil oil and aforementioned monoterpenoids are potent against insect pests. However, the molecular mechanism of action of those chemical constituents is not well-understood. W-3045 researchers at the University of Hawaii have discovered that linalool inhibits neurotransmitters GABAAR and nAChR, which may explain its insecticidal activity. Considering that multiple monoterpenoids are found within the same essential oil, it is likely that linalool has a synergistic effect with methyl eugenol characterized previously as both a GABAAR agonist and positive allosteric modulator and other monoterpenoids, thus offering a possible explanation for its sedative and anticonvulsant effects. The results of W-3045 member applied research are disseminated to the scientific community through publications in refereed journals, presentations and at national and international meeting venues. Sixty-seven (67) member peer reviewed publications for 2018-2019 related to this project are listed. In addition members presented research findings at national and international meetings, including the American Chemical Society, the Society of Environmental Toxicology and Chemistry, and the IUPAC International Congress of Crop Protection Chemistry. W-3045 AES members continue to collaborate and coordinate with USDA ARS – a recent example was joint participation in the Workshop on Innovation and Regulation in Agriculture – Incorporating the Benefits of Vegetative Filter Strips into Risk Assessment and Risk Management of Pesticides. December 3-5, 2018, Raleigh, NC. The outcomes and impacts of activities in 2018-2019 described above align with the following W-3045 project benchmarks: • Develop technologies in air, water, soil, biosolids, and composts that will aid in mitigating adverse agrochemical impacts to biota (including humans) and environment. • Provide communication-outreach on current and emerging agrochemical concerns to the science community, regulatory agencies, the agricultural industry and public. • Improve communication of agrochemical risks for humans and environment. Enhance capability of existing regulatory exposure models to reduce bystander risks. • Improve/refine watershed, aquatic organism, and migratory bird models for assessing the impact of agrochemicals on sensitive non-target plant/animal species and for wildlife protection. • Through applied research and outreach, reduce adverse impacts of agrochemical use on pollinators. • Identify new approaches and strategies to reduce pesticide use and address existing and emerging agrochemical concerns.