Environmental protection and improvement comes at a price, and regulators must ensure that resources are targeted at the highest priority risks. Risk assessment at a strategic level is now an essential tool. Risks can arise from natural sources such as flooding and radon, as well as anthropogenic sources such as discharges of pollutants or the introduction of alien fish species. In deciding which environmental pressure to tackle next, and which to leave, regulators have to compare the full range of risks on a sound and consistent basis. Comparing risks from such diverse sources poses a significant challenge and traditional hazard assessments are now no longer sufficient. Consideration now needs to be given to a much wider range of factors if risk assessment is to be used as an aid to strategic decision-making. In general, Strategic Risk Assessment can be broken down into four main tasks. (i) Harm assessment-where the impact of a given level of exposure on a predefined receptor group is determined. (ii) Risk significance-where the harm evaluated in (i) is placed in the geographical (regional, national international) context in relation to the overall population of receptors, and the range of different receptors. (iii) Risk uncertainty-where the probability of occurrence, exposure and harm is quantified together with the range of uncertainties involved in the overall assessment. (iv) Risk importance-where the costs and benefits of various actions/options together with a measure of society's view of the risk are brought together. All the above have been included in the Strategic Risk Assessment Methodology which has been developed by the Environment Agency, and will be used to direct the organisation's manpower and financial resources to maximise its contribution to sustainable development. (C) 1998 Published by Elsevier Science B.V. All rights reserved.
