ABSTRACT
This chapter considers a number of risk-based frameworks intended for various environmental management applications. The use of risk assessment to deal with chronic risks such as those associated with contaminated land is complementary to the more traditional approach of considering the environmental consequences associated with catastrophic events. In order that the risks associated with the exposure of ecosystems to chemical contaminants could be accommodated within a legal framework, the Dutch National Health Council evaluated various ecosystem risk assessment strategies. The distinction that is often made between 'qualitative' and 'quantitative' risk assessment leads to the implicit assumption that the latter is inherently superior. Risk characterisation summarises and integrates both the toxicity and exposure steps into quantitative and qualitative expressions of risk. The Hazard Ranking System (HRS) is a scoring system used by the US Environmental Protection Agency (EPA) and is the means by which the relative risks associated with the potential release of hazardous substances from waste sites are measured.
