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. 2011 Mar 31;119(8):1123–1129. doi: 10.1289/ehp.1002976

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National annual average models for PM_2.5, highlighting southern Ontario and the city of Toronto (A), and for NO₂, highlighting southwestern British Columbia and the city of Vancouver (B), that incorporate satellite-derived pollutant estimates, geographic land use variables, and deterministic gradients. The seven cities shown in (B) represent locations of independent monitoring data used to evaluate the national NO₂ and benzene models.