Canadian Ambient Air Quality Standards
(CAAQS) for fine particulate matter (PM 2.5 ) and Ozone have
been developed through a collaborative process involving the
federal, provincial and territorial governments and stakeholders,
as directed by the Canadian Council of Ministers of the Environment
(CCME) in October, 2010. The CAAQS replaced the Canada-wide Standards
(CWS) for PM 2.5 and Ozone that were established in 2000. The
ozone standard is currently the 3-year average of the 4th highest
daily maximum 8-hour average concentration set at a level of
60 ppb. In addition to the 8-hour ozone standard, the current
Canadian PM2.5 standard is 27 ug/m3 for 24 hours at the 98th
percentile averaged over 3 years. The 3-year average of the annual
average of the daily 24-hour average concentrations standard
is 8.8 µg/m3. In 2030, both the PM2.5 24-hour and PM2.5
annual standards will change to 23 ug/m3 and 8.0 ug/m3, respectively.
Additional information can be found by clicking here and here.
The Canadian government has realized that,
in some cases, exceedances of the two standards may be due to
activities not related to environmentally derived Canadian air
pollution sources. In jurisdictions highly impacted by transboundary
air pollution from the United States, achieving the CWSs will
be strongly dependent on reductions of this transboundary contribution.
Also,
high background levels of PM and ozone that may occur through
natural events, such as forest fires, natural formation, and
stratospheric intrusion, will need to be considered in assessing
achievement of the CWSs.
