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
62 ppb. In 2025, the ozone standard will be 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. 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.
