Where can I obtain hourly pollutant concentration data?

The Ontario Ministry of the Environment’s (MOE) Air Quality Index web site provides users with access to hourly pollutant concentration data from MOE’s ambient sites.The data output, which includes station and pollutant information, is available in both .HTML and/or .CSV format(s) which may be imported directly into Excel or any other spreadsheet application. Currently, online data is available from 2000 to 2012. The tool may be accessed at:http://www.airqualityontario.com/history/