Developing consensus: mercury science and policy in the NAFTA countries (Canada, the United States and Mexico)

The international science community has recognized methylmercury in the aqu atic food chain, as a potential environmental and human health risk. As a r esult, countries around the world have implemented a number of mercury mana gement initiatives. The United States, Mexico and Canada in consultation wi th stakeholders are developing a trilateral North American Regional Action Plan (NARAP) on mercury. Through public involvement in the decision making process, the NARAP has offered opportunities for more transparency in trans actions between governments, industry and stakeholders. In spite of the ava ilable scientific information, there are still important uncertainties asso ciated with the mercury issue. These knowledge gaps include: the most appro priate methylmercury reference dose for sensitive groups; the percentage of the North American population that is at risk from methylmercury exposure; spatial and temporal mercury deposition patterns in each country; the link between mercury emissions, atmospheric deposition and methylmercury concen trations in fish; and the relative magnitude of contributions from natural and anthropogenic sources. (C) 2000 Elsevier Science B.V. All rights reserv ed.