Brief Summary of Minutes of Annual Meeting

Objective 1: Identify, develop, and/or validate trace residue analytical methods, immunological procedures, and biomarkers. The authentication of foods is an important aspect of quality control and food safety. Scientists at the University of Hawaii (Honolulu) developed a fast and reliable method to determine the geographical origin of honey based on fingerprinting and barcoding of proteins in honey by using matrix assisted laser desorption ionization tandem time of flight mass spectrometry (MALDI TOF MS) and MALDI BioTyperTM software, respectively. The protein mass spectra of 16 known Hawai'i-origin honey samples were obtained and useful peak information was extracted and used to generate protein fingerprints. This information was then transformed into spectral barcodes for use as a spectral database library. The differentiation ability of the database library was validated using 5 of the 16 known Hawai`i-origin honey samples obtained directly from the producers. Validation results showed that the protein fingerprints of honeys have better comparability with those honeys in the library known to be from the same region than with those of honey samples from other regions. The protein fingerprints were used to differentiate the geographical origins of commercially purchased honey samples with labels indicating that they were produced in different countries and various states, including Hawai'i. A mass spectrum profile of proteins can be acquired in a few seconds, and MS spectral data can be readily transformed into protein fingerprint barcodes via MALDI BioTyperTM software. The results showed that using these techniques protein fingerprinting and barcoding can be a rapid, simple and practical method for determining the geographical origin of honeys sold in commerce. The muck soils of the north shore of Lake Apopka (FL) are high in organic matter, inorganic nutrients, and water content. Ideally suited for agriculture, these soils have been subjected to a wide variety of agrochemicals. Some of the more recalcitrant organochlorine pesticides, such as DDT and its degradation products DDD and DDE, have persisted in the soil for over thirty years. Scientists at University of Florida (Gainsville) used the extracellular enzymes from white rot fungi and demonstrated that it is possible to substantially reduce the amount of DDT, DDD, and DDE in this soil by more than 60% in three weeks. Objective 2: Characterize abiotic and biotic reaction mechanisms, transformation rates, and fate in agricultural and natural ecosystems. Land application of biosolids is a common practice throughout the world. However, concerns continue to be raised about the safety of this practice because biosolids may contain trace levels of organic contaminants. Scientists in Mississippi evaluated the levels of triclocarban (TCC), triclosan (TCS), 4-nonylphenol (4-NP), and polybrominated diphenyl ethers (PBDEs) in biosolids from waste water treatment plants and in soils from field plots receiving annual applications of biosolids for 33 years. All of the four contaminants evaluated were detected in most of the biosolids at concentrations ranging from hundreds of mg kg-1 levels to thousands of mg kg-1 levels (dry weight basis). They were detected at mg kg-1 levels in the biosolids-amended soil but their concentrations decreased sharply with increasing the soil depth, indicating limited mobility. The levels of all four compounds in the surface soil increased with increasing biosolids application rate. The mass balance estimations show that most of the PBDEs and smaller percentage of the 4- NP, TCC, and TCS introduced in the soil were recovered in the top 120-cm soil layer. These observations suggest slow degradation of PBDEs but rapid degradation of 4-NP, TCC, and TCS in the biosolids-amended soils. Excess nutrients and agrochemicals from non-point sources contribute to water quality impairment in the Chesapeake Bay watershed, with loading rates related to land use, agricultural practices, hydrology, and pollutant fate and transport processes. USDA-ARS scientists in Beltsville, MD, characterized monthly baseflow stream samples from 15 agricultural subwatersheds of the Choptank River, Maryland (2005 to 2007) for nutrients, herbicides, and transformation products. Streams were gauged to determine loading rates. High resolution digital maps of land use and hydrologic features were derived from remote sensing imagery. Mean nitrate concentrations (overall mean 4.9 mg/L) were correlated positively with percent agriculture (R2 = 0.60) and negatively with percent forest (R2 = 0.75); however, concentrations were higher in the well-drained upland (WDU) subwatersheds than in poorly-drained upland (PDU) subwatersheds (p = 0.02) suggesting increased denitrification in the PDU landscape due to prevalence of hydric soils. Springtime atrazine concentrations (overall mean 0.29 µg/L) were higher in WDU subwatersheds where riparian stream buffers were prevalent than in PDU subwatersheds where forested patches are typically not near streams (p = 0.02). Strong correlation with percent forest in the WDU subwatersheds provided evidence for capture of herbicide drift by the riparian forest canopy and subsequent wash-off during rainfall. Scientists at Cornell University studied the Fenton degradation of 4,6-dinitro-o-cresol (DNOC) under different experimental conditions using Amberlyst 15 ion exchange resin containing ferrous ion. DNOC was found to be effectively degraded under most conditions, and it was observed that, with the addition of HCl, the desorption of ferrous ion from the resin into the solution played a major role in this degradation. The total iron concentration in the reaction solution was found to increase with the addition of HCl, and a pseudo-first order kinetic model was applied to the desorption of ferrous ion from the resin based on the assumption of a first-order ion exchange process. The degradation rate of DNOC also increased as a function of HCl. A kinetic model was developed to simulate the degradation of DNOC under different operating conditions, assuming the first order desorption of ferrous ion. It was found that a lower pH could lead to faster degradation of the target compound. Degradation of DNOC under different delivery rates of H2O2 was studied and optimal conditions were determined. Scientists at University of Nevada (Reno) have continued the examination of photochemical processes on arid land soil surface, particularly the photochemical and thermal fixation of atmospheric nitrogen on arid lands soils and titanium dioxide. Photochemical fixation of nitrogen on soils was established over 20 years ago, but has received less attention in recent years. During the previous year we have provided strong evidence that nitrogen is also fixed thermally on titanium dioxide and soils to produce nitrate. For work completed since the last report, we have utilized isotopic (15N) methods for providing confirmation of atmospheric nitrogen incorporation into nitrate under thermal conditions. The results of this study support the production of nitrate, both by thermal and photochemical processes. However, the amount of nitrate produced containing the heavier isotope is less than expected and resulted in an incomplete understanding of the nitrogen fixation process. The impact of varying soil, landscape, and climate conditions on the off-site transport of pesticides must be determined to develop improved pesticide management practices. In collaboration with USDA-ARS scientists in St. Paul and Riverside, USDA-ARS scientists in Morris (MN) quantified the rate of S-metolachlor dissipation after fall and spring application in eroded and rehabilitated landforms in which topsoil was moved from areas of soil accumulation (lower slope) to areas of topsoil depletion (upper slope). Fall-applied metolachlor provided no control of annual grasses because ~80% was removed from the root zone during the winter and early spring, presumably by leaching and runoff. S-metolachlor dissipated in the spring with a half-life of 24 to 29 d. These results suggest that fall-applied metolachlor may not provide economic weed control and presents an increased risk of water contamination. Although landscape position and bulk soil movement within the landform had a large impact on soil properties, we observed no significant differences in metolachlor dissipation between different landscape positions and between eroded and rehabilitated landforms. Pesticides applied to turf grass have been detected in surface waters raising concerns of their affect on water quality and interest in their source, hydrological transport and use of models to predict transport. TurfPQ, a pesticide runoff model for turf grass, predicts pesticide transport but has not been rigorously validated for larger storms. USDA-ARS scientists in St. Paul (MN) evaluated TurfPQs ability to accurately predict the transport of pesticides with runoff following more intense precipitation. The study was conducted with creeping bentgrass [Agrostis palustris Huds.] turf managed as a golf course fairway. A pesticide mixture containing dicamba, 2,4-D, MCPP, flutolanil, and chlorpyrifos was applied to six adjacent 24.4 m x 6.1 m plots. Rainfall simulations yielded 13 events with which to test TurfPQ. Measured mean percentage of applied pesticide recovered in the runoff for dicamba, 2,4-D, MCPP, flutolanil, and chlorpyrifos was 24.6, 20.7, 14.9, 5.9, and 0.8 %, respectively. The predicted mean values produced by TurfPQ were 13.7, 15.6, 15.5, 2.5, and 0.2 %, respectively. Comparisons of the model estimates with our field observations indicate that TurfPQ under predicted pesticide runoff during 69.5 ± 11.4 mm, 1.9 ± 0.2 h, simulated storms. Sensitivity analyses indicated that errors in the organic carbon partition coefficient (KOC) of the pesticide and organic carbon (OC) estimates of the turf may contribute but were not the main cause of under predictions. The greatest source of error was in the timing of predicted infiltration and runoff, which influenced the predicted availability of pesticides for transport with runoff. Objective 3: Determine adverse impacts from agrochemical exposure to cells, organisms, and ecosystems. Scientists at Oregon State University evaluated the effectiveness of adapted and native woody plant species as drift barriers between cherry orchards and surface water resources in Wasco County (Middle Columbia-Hood Subbasin), Oregon. Wasco County contains nearly 9,000 acres of cherry orchards. Pest management includes the use of organophosphate insecticides, applied by airblast ground sprayers or fixed-wing aircraft. Two sites were chosen, one along Threemile Creek and the other along Mill Creek. Sites were chosen based on prevailing wind direction and riparian vegetation. At both sites the orchards slope down to the creek. However the two sites were distinct as to the distance from the edge of the application site to the creek. This distance is approx. 150m at the Threemile site and approx. 25m at the Mill Creek site. At each site two sampling areas were selected - an area with riparian vegetation between the orchard and the creek and an area without riparian vegetation. Spray deposition samplers consisted of Whatman No. 1 filter paper (23 x 26 cm), attached to rectangular aluminum frames. At each location a sampler was positioned horizontally at a height just above the orchard tree canopy, approx. 5m. Four or 5 samplers were located along two transects extending from within the orchard towards the creek. For one transect the sampler at the creek was intercepted by riparian vegetation and the other was not. Application of malathion ULV was by fixed-wing aircraft. Wind speed and direction, and temperature were monitored. Analysis was by gas chromatography with mass selective detection. During June, 2007 2 applications were sampled at each site. At the Threemile Creek site malathion concentrations within the orchard ranged from <0.01 to 1.47 ug/cm2. Malathion concentrations at Threemile Creek were 0.45 and 0.16 ug/cm2 for the transect without riparian vegetation, and 0.05 and 0.16 ug/cm2 with riparian vegetation. At the Mill Creek site malathion concentrations within the orchard ranged from <0.01 to 0.77 ug/cm2. Malathion concentrations at Mill creek were 0.09 and 0.13 ug/cm2 for the transect without riparian vegetation, and 0.05 and 0.08 ug/cm2 with riparian vegetation. These data suggest that the presence of riparian vegetation can result in a small reduction in pesticide stream loading via drift. Scientists at Purdue University analyzed liver proteome response of largemouth bass (Micropterus salmoides) exposed to environmental contaminants to identify novel biomarkers of exposure. Adult male bass were exposed to cadmium chloride, atrazine, PCB 126, phenanthrene, or toxaphene via intraperitoneal injection with target body burdens of 0.00067, 3.0, 50, 100, and 2.5 ¼g/g, respectively. After a 96 hr exposure, hepatic proteins were separated with two-dimensional gel electrophoresis and differentially expressed proteins (vs. controls) recognized and identified with MALDI TOF/TOF mass spectrometry. We identified, 30, 18, 18, five, and eight proteins as differentially expressed within the cadmium chloride, atrazine, PCB 126, phenanthrene, and toxaphene treatments, respectively. Alterations were observed in the expression of proteins associated with cellular ion homeostasis (toxaphene), oxidative stress (phenanthrene, PCB 126), and energy production including glycolysis (cadmium chloride, atrazine) and ATP synthesis (atrazine). This work supports the further evaluation of several of these proteins as biomarkers of contaminant exposure in fish. African rue (Peganum harmala) is an invasive herbaceous perennial that primarily invades disturbed areas. This species is toxic to cattle and sheep, and has been reported in eight western states, with its largest center of distribution is southern New Mexico and West Texas. Established populations are persistent and difficult to control. We evaluated the long-term response of African rue and associated vegetation to three herbicides (hexazinone, imazapyr, and metsulfuron). Scientists at University of New Mexico tested the effects of herbicide type, application date, and plant moisture stress on necrosis, African rue seedling density, and density of associated grasses and broadleaf plants at two locations in southern New Mexico. Herbicides were applied in Spring, Summer, or Fall 2004, and evaluated annually through 2007. At both sites, target plants sprayed with hexazinone and imazapyr were at least 30 to 40% more necrotic after 3 growing season relative to non-sprayed controls. Early necrotic response to metsulfuron was short-lived, and was not sustained after 2 growing seasons. Hexazinone was most effective when sprayed in June, whereas effects of application date were site-dependent for imazapyr. Imazapyr and metsulfuron reduced African rue seedling density after the first growing season, but this effect was short-lived. Density of African rue seedlings was significantly reduced by hexazinone, and a reduction of at least 50% was sustained through 3 growing seasons. Metsulfuron was least damaging to associated grasses and forbs. Both hexazinone and imazapyr significantly reduced associated vegetation. Supplemental water had negligible effect on herbicide efficacy. Overall, hexazinone provided the most effective control of mature plants and seedlings of African rue, but was also most detrimental to associated vegetation. Scientists at UC Davis evaluated farmworker exposure to cholinesterase pesticides. Court-ordered monitoring of blood cholinesterases (ChEs) from orchard workers in Washington State is underway. In 2008, the mean red blood cell acetylcholinesterase (AChE, EC 3.1.1.7) activity was 9.65 + 1.11 umoles/min/ml (n = 1793) and the mean serum (BChE, 3.1.1.6) activity was 5.19 + 0.90 umoles/min/ml (n = 1811). Determinations were made using the Ellman assay and automated equipment of Pathology Associates Medical Laboratories (PAML), Spokane, Washington. This will be one of the largest studies reported to date of farmworker baseline blood data. Scientists at Kansas State University sequenced and characterized 11 complete cDNAs encoding glutathione S-transferases (GSTs) in Chironomus tentans. Phylogenetic analysis revealed seven GSTs in three different cytosolic classes including 2 in delta (CtGSTd1, CtGSTd2), 4 in sigma (CtGSTs1, CtGSTs2, CtGSTs3, CtGSTs4) and 1 in omega (CtGSTo1). The remaining four GSTs (CtGSTu1, CtGSTu2, CtGSTu3, CtGSTu4) were unclassified due to their low relatedness to currently known classes of insect GSTs. Reverse-transcription (RT)-PCR analysis of the 11 GST genes showed that CtGSTd1, CtGSTu2, CtGSTu4, CtGSTs1, CtGSTs2, CtGSTs3, CtGSTs4 and CtGSTo1 were expressed in all tissues examined, including salivary glands, hemolymph, midgut, Malpighian tubules, fatbodies and carcass, whereas CtGSTd2 and CtGSTu1 were expressed in a limited number of tissues. RT-PCR analysis also revealed that CtGSTs1 and CtGSTs4 were only two genes that showed significant levels of expression in eggs, whereas all the 11 GST genes showed various levels of expression in all the four larval instars. Real-time quantitative PCR confirmed that the herbicide alachlor increased CtGSTd1, CtGSTs2 and CtGSTs3 gene expression by 2.1-, 2.8- and 4.3-fold, respectively, when fourth-instar midges were exposed to alachlor at 1,000 mg/L for 72h. Such increased expressions were associated with decreased total GST activities, and could be a counteractive measure at the transcriptional level to compensate the reduced GST activity in aquatic midges. Objective 4: Develop technologies that mitigate adverse human and environmental impacts. There is scant field fumigation emission rate information specific to Pacific Northwest cooler fall season application conditions. To help fill this fumigant emissions data gap, scientists at Washington State University (Tri Cities) applied Sectagon 42 (42% solution of metam sodium) to two treatment plots (1.7 acres for drizzle boom and 1.8 acres for shank injection) within a 122 acre field circle in Franklin County, WA in the fall of 2008. This study was developed to assess emission rates and total cumulative field loss of metam sodiums gaseous by-product, methyl isothiocyanate (MITC) during and four days post-application under typical Pacific Northwest potato pre-plant fumigation conditions. For each treatment plot, MITC concentrations (in ¼g m-3) were generated from air collected through activated charcoal at eight receptors spaced around the periphery before, during, and throughout the 4-day post application period. MITC field emission rates (¼g m-2 sec-1) together with total cumulative MITC loss over the 4-day post application period were estimated using an Industrial Source Complex Short Term (ISCST3) emissions model that utilized hourly meteorological data gathered at the field study location over the study time frame. California Department of Pesticide Regulations criteria for generating these near-field emission estimates. Drizzle boom test plot measured and modeled emission data were usually well correlated allowing emission rate estimation by linear regression. Upwind estimated MITC contribution from the higher emission drizzle boom plot, however, influenced the reliability for directly correlating field measured/modeled shank emission rates and necessitated a more conservative mean measured/mean flux estimation approach during application and up to 20 hours post-application. We did not attempt to subtract the estimated upwind MITC source contribution to the shank plot when calculating periodic emission rates or estimating total cumulative loss. Following Cal DPR emission criteria, the estimated total cumulative MITC loss by drizzle boom was 47% compared to 13% by soil incorporated shank injection. It is reasonable to anticipate some over-estimation of shank field emission rates. These two concurrent emission assessments provide flux data typical of the cooler fall climatic conditions when PNW fumigations are occurring.