PT03 Landscape-Scale Ecological Risk Assessment
Exhibit Hall
8:00 AM - Tuesday, 11 November 2003
(PT038) A Presumptive Risk Assessment: Exposure of Mammals to Agricultural Pesticides in South Carolina, USA.
Simpson, K. A. N.1, Johnson, A. 1, Allen, C.2, 1 Clemson Institute of Environmental Toxicology; Clemson University, Pendleton, SC, USA2 USGS South Carolina Cooperative Fish and Wildlife Research Unit; Clemson University, Clemson, SC, USA
ABSTRACT- Geographic information systems (GIS) are powerful tools applicable to a variety of environmental problems or questions addressed by a wide range of professionals. The versatility of GIS permits and even aids blending and merging of disciplines where appropriate for resolution of these problems or questions. Although merging of GIS and ecotoxicology is a relatively recent development, it is an appropriate approach for large-scale questions in environmental toxicology. Some techniques developed in landscape ecology are readily applicable to these problems. To illustrate this approach, we have conducted a presumptive risk assessment on a statewide basis for mammalian species of South Carolina based on the proximity of their habitats to agricultural areas. Habitat patches that may pose risk due to proximity to agricultural land were identified. Area, edge, edge/area ratios, and a relative index of potential exposure were calculated for these patches. Some pesticides, such as organophosphates (OPs), are of concern due to potential acetylcholinesterase inhibition effects on mammalian species. Other pesticides may not have direct deleterious effects on mammals at expected environmental concentrations, but may have indirect effects due to alterations of lower trophic levels. We analyzed data for pesticides used on widespread agricultural crops in South Carolina to estimate exposures and contrast pesticide effects data for indigenous mammalian/avian species. Pesticide exposures were estimated based on the acreage of major agricultural crops and recommended pesticide application rates. This analysis is an initial screening to identify species that may be at risk of exposure to and effects from the pesticides used on the major crops in South Carolina, as well as those species for which risks from these exposures are minimal or unlikely to result in any adverse effects. We summarized the possible cumulative effects that may occur in indigenous mammalian populations due to changes in land and pesticide use.
Key words: mammals, presumptive risk assessment, pesticides, agriculture