25. WHICH HUMAN AND TERRESTRIAL ECOLOGICAL RECEPTORS ARE MOST AT RISK FROM SMELTER EMISSIONS?

摘要

Base-metal smelters, which operated more than 100 years ago and may continue to operate, are found in many countries. These smelters have released sulfr dioxide (SO_2) and metal particulates (e.g., arsenic, cadmium, copper, nickel, lead, and zinc) into the local and regional environment. Human health risk assessments (HHRAs) and ecological risk assessments (ERAs) are required by contaminated site regulatory programs in many countries. Regional- or landscape-scale risk assessments are nearing completion for areas surrounding several of these smelters in Canada, the USA, and Europe. Valued ecosystem components (VECs) that were assessed in the terrestrial components of the ERAs are similar to those assessed in any terrestrial ERA, including plant communities, soil invertebrate communities, birds, and mammals. Results from completed ERAs clearly illustrate which VECs are most at risk. Although the emissions histories, ecosystems, metals, and VECs may be different, the conclusions are similar; plant communities are most at risk around smelters, and impacts to plant communities can have an impact on wildlife due to changes in habitat. In transition countries, such as Romania, the focus remains on human health impacts. Results from an HHRA conducted for a lead smelter in Romania are consistent with those for a lead smelter in Canada and results from smelters from other countries. Children are most at risk from ingestion of deposited dust from airborne emissions from lead smelters, but also from soil ingestion and dust inhalation. This can be monitored via a program to measure blood lead levels in young children. Various programs can be implemented to decrease exposure of children to metals around smelters. In addition, improvements in human health, plant communities (and wildlife habitats) can be made through the decrease in SO_2 and metal emissions.