University Graduate Fellow and Research Assistant (08/2001-12/2007)

 

U. S. Department of Agriculture, Agricultural Research Service, Beltsville, MD & University of Maryland College Park, College Park, MD.

Project based on investigating factors impacting the levels, phase distribution, and spatial and temporal trends of pesticides in the atmosphere of the Delmarva Peninsula.

 

  • Environmental Monitoring Program Management - Providing technical assistance in the development and smooth implementation of a monitoring -focused environmental assessment (air, precipitation) system for U.S. Department of Agriculture (USDA). Project objective was to characterize the environmental processes governing the fate and transport of pesticides (currently used and legacy) and brominated flame retardants in the atmosphere of the Upper Delmarva Peninsula. This is an important agricultural region within the Chesapeake Bay Watershed containing critical living resources habitat. Activities involved structuring and scoping of the environmental sampling; development and communication of sampling methodology; training site-operators in sampling of environmental media and coordinating sample collection activities over 4 years at 3 sites, development of data management tools; development of standard operating procedures for laboratory analysis and training laboratory support group; and development and presentation of reports for communication of results to research associates.

  • Environmental Modeling - Calibrated a nonlinear model to predict the levels of pesticides (current and legacy) and transformation products, and flame retardants in the atmosphere of Delmarva Peninsula (an agricultural region in the Chesapeake Bay watershed). Influence of agricultural cycle, local usage, and meteorological conditions on observed air levels and possibility of both long and short range transport was examined. The influence of sampling procedures, and meteorological conditions (like Relative Humidity) on vapor- particle partitioning and factors influencing wet deposition and scavenging were also examined. This required knowledge of environmental processes and applicability in a given situation; Trajectory analysis (HYSPLIT), analysis and examination of datasets (use of SAS). Performed statistical Analysis using GLM, LOGISTIC Regression modeling, NLIN; Experienced in producing external files and reports employing various SAS procedures. Developed new or modified SAS programs to load data from the source and create study specific datasets, which were used as source datasets for report generating programs and Exported SAS files to Excel.  

  • Environmental Impact/Risk Assessment- Evaluated the influence of regional activities and meteorological conditions on the observed levels of pollutants and atmospheric transport. Assessed the risk posed by wet deposition to the biota in the Chesapeake Bay.  Results will ultimately be used to design improved management practices to limit off-site transport of pesticides.

Accomplishments

  • Discovered that spray irrigation is an unknown source of Polybrominated Diphenyl Ethers (PBDEs) to the atmosphere.

  • Determined that wet deposition contributes only up to 17% of the annual pesticides load in the Chesapeake Bay.

  • Discovered that average measured concentrations of legacy organochlorine pesticides in Delmarva Peninsula rain are 2 to 10 times higher than in the Great Lakes.