Atmospheric Deposition Of Heavy Metals In Toronto

Atmospheric deposition rates of heavy metals (As, Cd, Co, Cu, Hg, Mn, Ni, Pb, and Zn) were determined from July 2009−December 2010 in downtown Toronto. Atmospheric deposition samples were collected using samplers with plastic, glass and water surfaces from two rooftops (15 m and 59 m above ground) in the city core of Toronto. Mercury species were analyzed using Cold Vapor Atomic Fluorescence Spectrophotometer (CVAFS) and the rest of metals were analyzed by acid digestion combined with Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). The results showed that the deposition of heavy metals was higher on water surface as compared to both the plastic and glass surfaces and that Cu, Mn, Pb and Zn showed higher deposition rates as compared to As, Cd, Co and Ni. The deposition rates were higher on Kerr Hall North (KHN) site indicating contribution from local sources. For total mercury (THg) and methyl mercury (MeHg), the deposition rates were higher on Jorgenson (JOR) site as compared to KHN site.