(MERAF) for the Base Metals Smelting Sector - CCME

are of additional concern from a federal government perspective. An overview of
health and environmental effects associated with these substances is provided in
Appendix A.
1.1.1. Particulate Matter and Ground Level Ozone
The primary drivers for reducing ambient levels of particulate matter and groundlevel
ozone are the effects these pollutants have on human health and the
environment.
Particulate matter refers to microscopic solid and liquid particles that remain
suspended in the air for some time. Particles give smog its colour and affect
visibility. Ground-level ozone is a colourless gas that forms just above the earth's
surface.
Ground-level ozone is considered a secondary pollutant because it is produced
through chemical reactions of two primary precursor pollutants: nitrogen oxides
(NOx) and volatile organic compounds (VOCs). Particulate matter can be both
primary pollutants and secondary pollutants. Primary particles are emitted
directly into the atmosphere (e.g., windblown dust and soil, pollen, automobile
and industrial exhausts or emissions). Secondary particles are formed through
chemical reactions involving the precursors NOx, VOCs, sulphur oxides (SOx),
and ammonia (NH3) 6 .
PM 2.5 (fine fraction of PM) is mainly a secondary pollutant. PM is a problem
throughout all seasons and in all regions of Canada, while ozone can be
characterized as a summer regional problem. These pollutants and their
precursors (such as NOX, VOCs, SOx) can be transported long distances by air
currents. Therefore, the air quality at a given site results from a mixture of local,
regional, and/or distant sources 7 .
Extensive scientific studies indicate that there are significant health and
environmental effects associated with these pollutants. Particulate matter and
ozone are linked to serious health impacts including chronic bronchitis, asthma,
and premature deaths. PM 2.5 has been recognized to have the potential for the
greatest health impact on a larger segment of the general population 8 .
The 1998 Science Assessment Document on National Ambient Air Quality
Objectives for Particulate Matter (PM) reports that exposure to particulate matter
is strongly linked to daily mortality, increased hospitalizations, and cardiovascular
and respiratory diseases. It also reports that PM 2.5 is linked to an increase in
respiratory hospitalizations and visits to emergency rooms. Fine particles (i.e.,
PM 2.5 ) are shown to have a stronger and more significant association with
mortality than coarse particles, as either the coarse fraction of PM 10 (i.e., PM 10-
2.5), PM 10 and/or total suspended particulate (TSP). Sulphate, considered a
6 Canadian Council of Ministers of the Environment. Backgrounder - Particulate Matter and
Ozone Canada-wide Standards. June 2000. URL:
http://www.ccme.ca/pdfs/backgrounders_060600/PM_Ozone_Backgrounder_E.pdf
7 Ibid.
8 Ibid.
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