Health risk assessments for alumina refineries.

OBJECTIVE: To describe contemporary air dispersion modeling and health risk assessment methodologies applied to alumina refineries and to summarize recent results. METHODS: Air dispersion models using emission source and meteorological data have been used to assess ground-level concentrations (GLCs) of refinery emissions. Short-term (1-hour and 24-hour average) GLCs and annual average GLCs have been used to assess acute health, chronic health, and incremental carcinogenic risks. RESULTS: The acute hazard index can exceed 1 close to refineries, but it is typically less than 1 at neighboring residential locations. The chronic hazard index is typically substantially less than 1. The incremental carcinogenic risk is typically less than 10(-6). CONCLUSIONS: The risks of acute health effects are adequately controlled, and the risks of chronic health effects and incremental carcinogenic risks are negligible around referenced alumina refineries.