Probabilistic Environmental Risk of Hazardous Materials

Abstract
To help quantify the potential devastation of an environmental accident involving hazardous materials, local, state, and federal agencies have turned to risk assessment methodologies. Risk is commonly defined as the expected cost or monetary loss of an environmental accident and is based on the probability of the accident. This definition of risk is clearly evidenced by the media coverage of environmental disasters such as the Exxon Valdez oil spill and the potential risk surrounding nuclear power plants. However, environmental risk should reflect the probability that an environmental system, or component of that system, can recover from an environmental accident. Environmental risk should address issues such as the interaction between our development and the impact on the environmental system being considered. This paper presents one possible model for determining the probability that an environmental system is able to recover from changes resulting from accidental ecosystem perturbations. A second moment approach commonly applied in reliability analysis is used to quantify the probability that the environmental system will fail due to the introduction of incompatible human activities.