Spatial and Temporal Exposure Characterization

Spatial and Temporal Exposure Characterization

The potential exposure of nontarget organisms (plants, invertebrates, and mammals alike) and habitat areas to agrochemicals is increasingly important in the risk assessment process. To characterize potential exposure, the relationships Map layers created by a GIS between source areas and nontarget areas must be examined. These relationships incorporate environmental factors that vary over time and geographic area. Using a geographic information system (GIS), these factors can be quantified for each nontarget area (such as a stream or hedgerow) over a large geographic area. The resulting distributions provide a baseline from which to select specific end points for exposure analysis.

For regulatory purposes, hundreds (or thousands) of water bodies are sampled and evaluated using frequency curves to provide statistically significant data on overall potential exposure for a particular region.

Using a GIS in conjunction with models can help you answer many questions:

To what extent and magnitude do agriculture and aquatic systems interact?
How frequently will concentrations exceed levels of concern?
How much diversity in land cover is present within the region of interest?
What percentage of agriculture within the study site potentially exposes nontarget areas?
How often does agriculture occur directly adjacent to critical habitat?
How often are water bodies that potentially could be exposed protected by naturally occurring vegetation?
How do soil characteristics affecting chemical transport vary across the study area?

Waterborne staff has extensive experience in conducting spatial and temporal exposure characterizations worldwide.