LEAD, CADMIUM, ARSENIC AND ZINC IN THE ECOSYSTEM SURROUNDING A LEAD SMELTER

A lead smelter has been operating at Belledune in the province of New Brunswick, in eastern Canada, since 1966. This paper presents data on the concentrations of the four primary metals emitted from the smelter - lead, cadmium, arsenic and zinc - which were measured in the terres trial environment near the smelter and the concentrate transport route . Deposition of these metals to the snowpack and the uptake by grass f orage are discussed in relation to non-regulatory guidelines, toxicity and atmospheric emissions. A 1992 snowpack transect survey extending 0.5-40 km northwest, southeast and south of the smelter revealed lead concentrations of 2-3193 ppb, cadmium < 0.10-49.7 ppb, arsenic < 3.0-7 2.0 ppb, and zinc 3-401 ppb. Deposition estimates within this zone for lead were between 0.046 and 20.1 kg/ha/yr, cadmium < 0.007 and 313 g/ ha/yr, arsenic < 0.016 and 453 g/ha/yr and zinc 0.020 and 2.52 kg/ha/y r. Concentrations of these metals in the snowpack were highest within 3 km of the smelter and were detectable at greater distances SE of the smelter. Lead was dispersed greater distances from the smelter than c admium or arsenic. Snowpack samples collected within 5-20 m of the rai lway contained 140-7270 ppb of lead, 0.4-36.9 ppb of cadmium, < 3.0-72 .0 ppb of arsenic and 41-13100 ppb of zinc. Grass forage sampled withi n 0.6-16 km of the smelter contained lead 5-152 ppm, cadmium 0.10-4.1 ppm, and zinc 22-154 ppm. Highest concentrations of lead, cadmium and zinc in grass forage were found within 2.2 km of the smelter. Grass fo rage collected within 10-70 m of the railway contained lead 13-288 ppm , cadmium 0.4-1.3 ppm and zinc 98-831 ppm.