Gaseous Elemental Mercury (GEM) in downtown Toronto

Abstract

\nGaseous elemental mercury (GEM) concentrations in downtown Toronto, Canada were monitored\nfrom June 2001 - February 2002 at two levels (3.5 and 7m) above the ground. The mean quarter-hourly\nconcentrations for the time series were 2.39 ng/m$^3$ for the bottom line and 2.57 ng/m$^3$ for the top line. When\ndivided seasonally, the highest concentrations were observed in the summer months 3.03 ng/m$^3$ (bottom) and\n3.31 ng/m$^3$ (top) and the lowest values were observed in the fall with 1.84 ng/m$^3$ (bottom) and 1.97 ng/m$^3$\n(top). When analysed over a 24 scale, the pattern was characterized by highest GEM concentrations during\nthe daytime relative to nighttimes. The results will be compared with those obtained from the rural and\nremote sties in the Canadian Atmospheric Mercury Measurement Network (CamNet).\n