The Peconic River: Concerns associated with different risk evaluations for fish consumption

Risk evaluation and assessment have been used as tools to regulate and manage the risks to consumers of eating self-caught fish that have high levels of contaminants. Armed with these risk assessments, health agencies issue consumption advisories, and in some cases, close some waters to fishing. Recently, regulatory agencies have used contaminant levels in fish as a benchmark for remedial action on contaminated sites, using human health risk assessment as the justification. The US Environmental Protection Agency's new surface water criterion for mercury is based on mercury levels in fish tissue. When multiple regulatory agencies have jurisdiction over the same waters or remediation site there is the potential for differing risk evaluations. Using the Peconic River on Long Island, New York as a case study, the paper examines how and why county, state, and federal health risk evaluations for fish contaminated with mercury differed. While the same risk methodology was applied by all agencies, the assessments were conducted for different purposes, applied different consumption and fish biomass assumptions, and arrived at different conclusions. The risk evaluations invoked to design fish consumption advisories use mercury levels currently in fish, and are designed to prevent current exposure. However, the risk assessments that provide a basis for remediation consider many different pathways of exposure (not just ingestion), and deal with long-term exposure. The risk evaluations, and recommendations promulgated by those agencies, differ because they have different goals, use different assumptions, and often fail to communicate among agencies. It is suggested that it is valuable to have these different levels of risk evaluations to adequately address health issues. However, there are policy implications, which include making the distinctions between the types of risk assessments, their methods and assumptions, and the rationale for these assumptions. Further, assessors and managers should involve all interested stakeholders (including regulators and state health officials) in discussions about the use of risk, the assumptions of risk assessment, and the goals of those evaluations. The difficulties in the case of the Peconic were not due to differences in the original data, but rather in the goals and type of risk assessments performed. If all deliberations had been transparent during all phases of the decision-making and management process, the conflicts within the minds of the public, regulators and other agencies might have been avoided. This case study suggests that more reliability, circumspection and transparency should be built into the process where multiple agencies and multiple objectives are involved.