Spatially explicit exposure assessment of persistent pollutants through the food chain of the European hedgehog (Erinaceus europaeus).

摘要

The characteristic vegetation in different habitat types is an important determinant for the amount of persistent pollutants that reaches the soil after atmospheric deposition. Habitat-specific soil characteristics, such as pH and organic matter, determine the bioavailability of these compounds to organisms living in close proximity with soil. Soil dwelling invertebrates, such as earthworms, beetles and woodlice, constitute a major part of the diet of the European hedgehog (Erinaceus europaeus) and exhibit a spatial distribution that is related to certain habitat types. As a result, soil and biota show spatially explicit contamination patterns. So far, the distinct (horizontal) classification of habitat types has not been taken into account in bioaccumulation studies from soil to biota. Moreover, if the ecological receptor of concern in an exposure assessment is a predator situated higher up in the food chain, its movement across habitat types within the study site should be considered as well. This necessitates the study of the predator's foraging behavior to reveal which areas are actually used for feeding, since this will largely affect the degree of exposure. Up till now, real life foraging data are rarely used in site-specific exposure and risk assessments.;The main objective of this doctoral thesis was to perform a spatially explicit exposure assessment. Therefore, the foraging behavior of two hedgehog populations was used to relate prevailing soil contamination in different habitat types to measured hair concentrations of metals and organochlorine and organobromine compounds. In addition, the bioaccumulation of these persistent pollutants from soil to invertebrates was studied in function of different habitat types.;The results of this thesis illustrate the importance of habitat as a key element in soil contamination and indicate that site-specific distinction of habitat types contributes towards a more relevant assessment of bioaccumulation and risk. The spatially explicit exposure assessments presented in this thesis showed the potential of estimating exposure to soil contamination based on prevailing soil concentrations and individual exposure time, derived from field-based foraging data.