Estimating environmental exposure of emerging agricultural contaminants using spatial data analysis and geographic information system

Debjani Deb, Purdue University

Abstract

Agricultural activities generate a wide range of potential contaminants that can degrade the quality of both surface and ground water, resulting in significant public health and environmental impacts. Amongst potential contaminants connected with farming, livestock antibiotics and hormones and soybean rust fungicides have only recently emerged as concerns. The use of antibiotics and hormones as growth promoters and anti-bacterial agents in the feed of most livestock, and the use of fungicides to control soybean rust are believed to play a leading role in the release of these substances into the environment. While livestock antibiotics/hormones are increasingly being found in water bodies, and have already been observed to cause extreme biological responses at low (ng/l) concentrations, fungicides are more of a future threat in states such as Indiana as they will likely be used to control soybean rust (a potentially devastating disease for soybeans in US) and may reach water resources and impact "off target" species such as fish and humans. Therefore, it is essential to assess the possible environmental impacts of these potential contaminants and identify areas that are most vulnerable to contamination. This study focuses on developing and applying modeling techniques to estimate the potential magnitude and spatial patterns of water resources contamination by these emerging agricultural contaminants. This was achieved by developing a mathematical screening tool as a first step to estimate the possibility of contamination of shallow groundwater. Model results for the State of Indiana demonstrate that transport rates and paths are highly sensitive to soil patterns and characteristics, and illustrate how this approach can be used to create spatial maps of leached fractions beyond a control plane. This was followed by a statewide risk assessment of both livestock antibiotics/hormones and the soybean rust fungicides. Assessment results indicate the regions in Indiana that are vulnerable to contamination by these two groups of compounds. The outputs of this study demonstrate the scale of the potential risk posed by these emerging contaminants and also establish a framework for developing comprehensive management and mitigation plans.

Degree

Ph.D.

Advisors

Harbor, Purdue University.

Subject Area

Plant propagation|Environmental science

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