Mercury policy in the Great Lakes states: past successes and future opportunities.

While mercury (Hg) releases to air and water within the Great Lakes states have declined significantly, concentrations of mercury in fish remain a cause for concern regarding human and ecosystem health in the Great Lakes Basin. This paper assesses the priority that Hg source reduction ought to have in relation to some other environmental concerns, and explores the relative costs of various Hg reduction policies. Long-range transport of atmospheric mercury creates a collective action problem for states, since most of the mercury emitted within any given state deposits outside that state's borders, and since most of the mercury deposited within a state originated outside that state. This paper discusses some of the mechanisms that policy makers in the Great Lakes states employed to get beyond the collective action problem, including: providing an example for others to follow; using cross-jurisdiction cooperation to leverage the benefits of leadership on Hg reduction and control; and, promoting voluntary actions. Recommendations for future opportunities include: focusing reduction efforts on sources with the highest total mass of emissions rather than solely focusing on reduction of local deposition and utilizing all tools available in the clean air and clean water acts.