A report on the third step in detailed Human Health Risk Assessment for smelter-related metals, other than lead. In this phase, the two metals identified in Phase 2 as warranting some further assessment, arsenic and cadmium, were evaluated again incorporating new outdoor air and indoor dust data. Antimony was included again, despite the finding of negligible risks in Phase 2 because no data for antimony in soils had been available for some of the neighbourhoods being assessed.
The risk assessment in Phase 3 used data for antimony, arsenic and cadmium concentrations in Trail area soils, air, indoor dust and locally grown produce, and employed prescribed methods from regulatory agencies in BC (or Canada or USA where not prescribed for BC) to estimate long-term exposures and risks to residential, commercial and agricultural land users. Estimated risks of adverse health effects associated with a full lifetime of exposure in Trail were confirmed to be low, but still somewhat above target levels. Therefore, the Phase 3 report recommended continued monitoring of air concentrations of arsenic and cadmium in order to confirm ongoing anticipated improvements in air quality.
