Samples were collected at several sites, all within 10 kilometers of the source. SO 2 measurements were made simultaneously at several sites. Size segregated aerosol samples were collected at two sites daily and analyzed for copper, nickel, arsenic, lead and cadmium. There are two main pieces of information we can learn from this data set. First, the size segregated aerosols can tell us which metals are likely to have the most long range impact.
Smaller particles stay airborne much longer than larger particles.
Therefore, because arsenic and lead were found to be in smaller size range particles as compared to copper and nickel, they will be disproportionally represented in the emissions of the smelter that are transported great distances. The second valuable piece of information that can be determined from this data set is an estimate of the emissions of the smelter. Since relatively reliable annual SO 2 emissions are published each year, a ratio between airborne concentrations of SO 2 and each metal was established. Multiplying the SO 2 annual emissions by the established ratio gives an estimate of the metal emissions of plant. The best ratios of metals to sulfur dioxide are shown in Table 1.