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United States Department of Agriculture

Agricultural Research Service

2008 Annual Report

1a.Objectives (from AD-416)
The overall goal of this bridging project is to investigate the potential pollutants and agricultural management practices that affect air quality within the Chesapeake Bay region. Agricultural activities in this region have traditionally been production of corn, soybeans, and specialty crops and some confined animal operations; however, production of bioenergy crops including corn, hulless barley, and switch grass are expected to increase as energy costs rise. Urban encroachment has also become a major concern in this region resulting in increased NOx production which can lead to ozone formation in the presence of VOCs. Objective 1: Identify the major emission sources of agricultural pollutants, such as particulate, pesticide active and inert ingredients and other VOCs, and greenhouse gases within the Chesapeake Bay airshed. Objective 2: Determine the predominant fate processes and atmospheric components that influence the fate of agricultural air-borne pollutants. Objective 3: Estimate the spatial and temporal variability of emissions using a combination of field measurements, remotely-sensed, and land use data. Objective 4: Develop a framework to predict the influence of land use changes and agricultural production practices on air quality for use by policy makers, regulators, and natural resource managers.

1b.Approach (from AD-416)
Rapid detection technologies, such as nano and molecular imprinting technologies, will be developed for measuring agricultural pollutants in air. Using newly-developed and traditional techniques, the emission of air-borne pollutants will be measured in selected subwatersheds. Measurements will be taken over several growing seasons in different land use areas and compared to a previously-identified non-urban area where no agricultural activities have occurred for over thirty years. The fate of identified air borne pollutants will be examined in newly-developed chemical fate models. In areas where urban land use is adjacent to agricultural lands, available NOx and meteorological data will be utilized to predict the potential of agricultural pollutants to form ozone. Predictions will be compared to available ozone concentrations. Measured pollutant concentration data will be combined with land use, physical chemical constants, and meteorological data to produce an estimate of total emissions and potential ozone emission as a function of land use. These data will then be extrapolated to consider the effects of land-use changes and agricultural activity on air quality in the Chesapeake Bay region.

3.Progress Report
This bridging project utilizes the Choptank River Watershed Conservation Effectiveness Assessment Project located on the Delmarva Peninsula as a platform to investigate the potential pollutants and agricultural management practices that affect air quality within the Chesapeake Bay region. The Choptank River Watershed can be viewed as a microcosm of environmental pressures emerging in agricultural regions across the U.S., i.e., economic influence of bioenergy demand, urban encroachment, and increasing regulatory restrictions. Research gaps were identified and were presented with summary of research results at the Maryland Pesticide Network, Pesticides and the Chesapeake Bay Watershed Project, Second Annual Stakeholder’s Meeting; the Choptank River Watershed Conservation Effects Assessment Project Customer Workshop; US EPA Chesapeake Bay Program Office, Toxic Substances Committee Meeting; and US EPA, Office of Pesticide Projects, Exposure Modeling Work Group Public Meeting. Chesapeake Bay watershed water quality data were submitted and were used by outside scientists to provide the policy makers with an initial assessment of the potential risks associated with landuse changes due to increased production of bioenergy crops. Presentations were made to La Federacion Latinoamericana de Asociaciones de Quimica at the XXVIII Latin American Chemical Congress concerning land use changes and environmental quality changes associated with bioenergy production and biofuel use and at a congressional briefing. Scientists participated in the NP212 Customer Workshop for Air Quality and Global Change and took the lead in assembling the emissions component.

The sibling project 1265-12220-004-02S, “INVESTIGATING THE ENVIRONMENTAL CHEMISTRY FATE AND TRANSPORT OF AGROCHEMICALS AND OTHER POLLUTANTS”, a specific cooperative agreement with University of Maryland expired in July 2008. This five year project has resulted in a number of important studies and has complimented the previous project plan and the new bridging project. A proposal for a new cooperative agreement to extend this effort has been submitted. Currently two graduate students and one visiting scientist are participating in this cooperative project. One project examines the fate of flame retardant chemicals (polybrominated diphenyl ethers) and antimicrobial chemicals (triclosan) in agricultural soils receiving biosolids applications. The second study examines the impact of land use on pesticide and nutrient fate in the Choptank River watershed/airshed. Previous research studies focused on atmospheric transport and deposition processes controlling the fate of agricultural pesticides in the Chesapeake Bay region.

This project contributes to NP 203 Air Quality: Pesticides and Synthetic Organic Compounds Component; it also addresses NP 211 Water Resource Research: Water Quality Protection Systems.

1. PESTICIDE AND NUTRIENT FATES DIFFER IN CHOPTANK RIVER SUBWATERSHEDS Farmers utilize conservation practices such as tree or grass buffers or cover crops to protect water resources from nutrient and sediment contamination. In the Choptank River Watershed project, stream water from 15 small watersheds with differing amounts of agriculture and conservation practices were compared for nutrient and pesticide contamination throughout the year. The lowest concentrations of nutrients were found in watersheds with the largest amount of forested areas and did not vary widely during the year; however, pesticide concentrations were highest in spring just after application and did not correspond with any category of land use in the watershed. This work supports the idea that nutrients are delivered primarily by groundwater in this region and movement of pesticides to streams is more complicated as delivery can occur via leaching, overland flow, and atmospheric delivery to riparian corridors via drift and/or volatilization. This project contributes to NP 203 Air Quality: Pesticides and Synthetic Organic Compounds Component; it also addresses NP 211 Water Resource Research: Water Quality Protection Systems.

2. FORAGE CONTROLS PERCHLORATE LEVELS IN MILK Perchlorate has been detected in U.S. milk samples from many different states. Applying data from a recently reported 9-week experiment in which 16 Holstein dairy cows were administered perchlorate allowed us to derive an equation for the dose-response relationship between perchlorate concentrations in feed/drinking water and its appearance in milk. Examination of background concentrations of perchlorate in the total mixed ration (TMR) fed in addition to the variable dose supplied to treated cows as a ruminal infusate revealed that cows receive significant and variable exposure to perchlorate from the TMR, and analyses of the ingredients comprising the TMR revealed that 41.9% of the perchlorate came from corn silage, 22.9% came from alfalfa hay and 11.7% was supplied by sudan grass. USDA Food and Nutrition Survey data on fluid milk consumption were used to predict potential human exposure from milk that contained concentrations of perchlorate observed in our previous dosing study, and the study suggests that reducing perchlorate concentration in dairy feed may reduce perchlorate concentrations in milk as well as the potential to reduce human exposure to perchlorate in milk. This project contributes to NP 211 Water Resource Research: Water Quality Protection Systems.

3. FLAME RETARDANT CHEMICALS SURVEYED IN BIOSOLIDS-AMENDED AGRICULTURAL SOILS Biosolids, generated during wastewater treatment are materials, high in organic carbon and nutrient content are often used as soil conditioners on agricultural lands. Concerns exist over the persistence and potential toxicity of flame retardant chemical residues present in biosolids as a result of their use in consumer products. Soil samples were collected from agricultural production fields which had received zero, one, or multiple applications of biosolids, and biosolids samples from the source wastewater plant were also collected every other month over one year. Results indicate that soil concentrations of flame retardant chemicals called polybrominated diphenyl ethers (PBDEs) averaged a factor of 2 higher in soils which have received a single biosoilds application within a three year period and averaged a factor of 10 higher in soils which had received two or more applications in the past 10 years, and the pattern of PBDEs in the treated soils mirrored that of the source biosolids. These results indicate that PBDEs are relatively persistent in soils, but further research is required to examine the potential risks to wildlife and human populations. This project contributes to NP 203 Air Quality: Pesticides and Synthetic Organic Compounds Component; it also addresses NP 211 Water Resource Research: Water Quality Protection Systems.

5.Significant Activities that Support Special Target Populations

6.Technology Transfer

Number of Non-Peer Reviewed Presentations and Proceedings4

Review Publications
Mcconnell, L.L., Rice, C., Hapeman, C.J., Drakeford, L., Harman-Fetcho, J.A., Bialek Kalinski, K.M., Fulton, M.H., Allen, G. 2007. Agricultural Pesticides and Selected Degradation Products in Five Tidal Regions and the Mainstem of Chesapeake Bay. Environmental Toxicology and Chemistry. 26(12):2567-2578.

Loyo-Rosales, J.E., Rice, C., Torrents, A. 2007. Fate of Octyl- and Nonylphenol Ethoxylates and Some Carboxylated Derivatives in Three American Wastewater Treatment Plants. Environmental Science and Technology. 41(19):6815-6821.

Rice, C., Baldwin, R.L., Abbott, L., Hapeman, C.J., Capuco, A.V., Le, A.N., Bialek Kalinski, K.M., Bannerman, D.D., Hare Jr, W.R., Paape, M.J. 2007. Predicting Perchlorate Exposure in Milk From Concentrations in Dairy Feed. Journal of Agricultural and Food Chemistry. 55:8806-8813.

Last Modified: 2/27/2015
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