The precautionary principle: Protecting against failures of scientific method and risk assessment

The precautionary principle has been increasingly incorporated into national and international legislation to protect the environment from anthropogenic impacts. Suggestions for redefinition of the principle have been made (Gray and Bewers, 1996). Adopting these suggestions would entail using a risk-based approach to environmental protection rather than a truly precautionary approach. There remain enormous gaps in our understanding of the identity and of the individual or combined toxicity of chemicals released to the marine environment. This is also true of the actual doses involved in environmental exposures, whereas the most appropriate ways of determining ecosystem impacts have not yet been identified. Classical toxicological assumptions applied to dose-response relationships can no longer be regarded as universally applicable. Ecotoxicology, consequently, contains irresolvable indeterminacies. It is clear, therefore, that the continuing application of the precautionary principle as a paradigm for regulatory action, as a means of recognizing and accounting for limitations to scientific evidence, is an approach that is both scientifically defensible and capable of ensuring a high level of environmental protection.