Comparing environmental risks: a consultative approach to setting priorities at the community level.
Environmental risk management is facing a crisis. The number of recognized environmental hazards has clearly outstripped the resources available to do detailed studies on each or to establish effective control measures for each on an individual basis. Some method of prioritizing environmental hazards is required that does not involve detailed and individualized quantitative risk assessment. An alternative approach that has gained favour in recent years has been "risk comparison", as sponsored by the U.S. Environmental Protection Agency and as applied in several American states and local communities. Risk comparison is an approach that involves expert panels and the interested public in a consultative and iterative process leading to widespread agreement, if not consensus, on the relative rankings of often disparate environmental hazards. An outline of steps in the process formulated by the Northeast Center for Comparative Risk at the Vermont Law School is presented with commentary regarding its applicability to the Canadian scene. Implicit tradeoffs in risk comparison are also explored, including emphasis on categorical hazards v. media quality, magnitude of hazard v. population affected, ecological integrity v. human health, social concern v. scientific assessment, and novel v. familiar hazards. In practice, risk comparison is a process-oriented and often tedious approach, but it represents one way out of the current conundrum in dealing with environmental hazards.