Risk assessment should be seen in the broader context of moving towards an environmentally sustainable society based on clean production. Standard risk assessments can provide information about the probability of certain events and their likely consequences. However, this should only be one element in a decision-making process on whether to proceed with the activity which gives rise to the risk. Over-emphasis on this aspect can detract from consideration of other issues such as social need, availability of alternatives or irreversibility of effects.
Communication about risks often amounts to communicating the results of risk assessment. Risk assessment can be a powerful tool when dealing with well delineated systems, where the hazards are well defined (e.g. traffic). But it has also been applied all too frequently in the past to complex systems where the hazards are poorly defined and/or completely unpredictable (e.g. genetically modified organisms). This has contributed in some part to the increasing scepticism with which the public has treated health and safety information in recent decades.
Ultimately, society needs to adopt an entirely new approach to risks and hazards – one which is preventive, pre-emptive and pro-active, rather than reactive and based on damage limitation after the event. Pervasive technologies which are reasonably suspected of having the potential for substantial, irreversible or uncontainable effects should not be developed until it has been established beyond reasonable doubt that they will not produce such effects.
This strategy features in the framework of Agenda 21 as formulated at UNCED (Rio de Janeiro, 1992), now coordinated by the United Nations Commission on Sustainable Development and implemented through national and local authorities. Agenda 21 recommends use of risk assessment and risk management in reaching decisions on water pollution and control and ensuring compliance with those decisions.
Governments should encourage maximization of the identification and quantification of hazards within any given risk assessment, thus reducing as far as possible the number of assumptions related to modelling. As regards the assumptions that remain, it is important that these are clearly stated and that the precautionary principle is rigorously applied. Aside from the difficulty of accurately and confidently quantifying risks, the question of their acceptability depends on a range of other issues which involve subjective value judgements. This implies a need for broad societal input into decision-making on risks, the role of value judgements and the treatment of scientific uncertainty in risk assessment.