B.C. Air Quality

How We Measure Air Quality

The Province of British Columbia uses a number of methods to measure air quality, including permanent monitoring stations in communities, mobile instrumentation (e.g. on a truck or airplane), and industrial stack monitoring.

These monitoring stations measure the presence of contaminants in the air, such as carbon monoxide (CO), nitrogen dioxide (NO2), ozone (O3), particulate matter (PM2.5 and PM10), sulphur dioxide (SO2), and hydrogen sulphide (H2S).

You'll find more detailed information on measuring air quality in Air Quality Monitoring.

How We Collect and Measure Data

Contaminants are measured in one of two ways: either through continuous (real-time) or noncontinuous (discrete) monitoring. In continuous monitoring, air is constantly measured and the data is automatically transmitted to a central database. In noncontinuous monitoring, contaminants collect on a filter or canister over a specified period of time (such as one, three or six days). Then a technician collects the filter or canister and sends it to a certified laboratory for measurement and analysis.

How We Analyze the Findings

Continuous and noncontinuous data are housed in a central data warehouse of the Ministry of Environment where they are screened by data validation technicians for errors. Once the data has been certified as correct (i.e., validated), the data can then be used for reporting out to the public, comparing with objectives and guidelines, regulatory purposes, and by scientists for more detailed analysis.

How We Report Our Findings

Current, nonvalidated data from continuous monitoring stations is published hourly on our website. This data forms the basis for the Air Quality Health Index (AQHI). The AQHI is updated hourly for a number of communities in British Columbia.

Validated data can also be found on the site [link to come]. This data is used to produce a number of reports, including regional reports, an annual State of the Environment report, and reports by third parties, such as the BC Lung Association, and the Office of the Provincial Health Officer.

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