Wildlife exposure assessments study designs

The first step in a wildlife exposure assessment is to document the occurrence and persistence of a pesticide in the study area throughout the study duration. Several articles in this book describe the experimental designs and best practices to conduct field crop and environmental dissipation (air, soil and water) studies. This article presents methods to quantify spatial and temporal distributions of pesticide presence in ecosystems following normal application and resultant exposure of nontarget wildlife. 

Studies may be designed for estimating exposures to a wide array of wildlife, including birds, mammals and amphibians. Many regulatory requirements involve birds, and less emphasis is currently placed on other species. As regulatory requirements evolve, ecological risk assessments will be required for more species. This may require alternative approaches for food item analysis to allow estimates of pesticide ingestion. 

Only circumstantial evidence is available that supports the supposition that wildlife species are exposed to explosive compounds. Studies conducted at U.S. Army ammunition plants and other areas of known soil contamination have failed to detect body burdens of suspected explosive compounds in mice, deer, and some bird species [4-7] (see Chapter 10 in this book for a more complete review). Given the relatively rapid metabolic potential of many explosives in vivo, the heterogeneous distribution of these substances in the environment, and the potential for bioaccumulation of some nitramines in plants, body burden analysis may not adequately describe exposure potential. Therefore, the data reviewed in this chapter will focus on controlled laboratory toxicity studies conducted to evaluate the effects in wildlife species, many of which were designed for specific risk assessment applications. 

---