A report on the second step in detailed Human Health Risk Assessment for smelter-related metals, other than lead. In this phase, the eight metals identified in Phase 1 as potentially warranting detailed assessment in Phase 2 were considered further. As a result of new soil sampling and analysis, only three of these (antimony, arsenic and cadmium) were found to exceed soil screening levels beyond the smelter property boundary. A comparison of concentrations of all eight metals in air monitoring data against air screening levels concluded that only arsenic and cadmium posed potential risks from inhalation. Therefore, only antimony (due to concentrations in soil), arsenic and cadmium (due to concentration in both soil and air) were carried further in the Phase 2 risk assessment.
The risk assessment in Phase 2 used data for antimony, arsenic and cadmium concentrations in Trail area soils and air, 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. The estimated risks from exposures to antimony in soil and air were negligible. For arsenic and cadmium, estimated risks were low, but still deemed to warrant further assessment and updating as environmental conditions continued to improve in Trail, particularly as air concentrations of arsenic were expected to continue to decline.