The goals of the Air Quality Partnership are to increase the public's understanding
on the impact of air pollution, provide alerts for days with high air pollution,
provide health effects information and guidelines to prevent or reduce exposure,
and finally encourage voluntary actions to reduce air pollution emissions, especially
on "Action Days".
The Partnership forecasts "Action Days," or days when the air is expected to be
unhealthy to breathe. Using a color-coded scale, the forecast informs people about
the predicted ozone and fine particulate matter (PM2.5)
levels and any precautions that need to be taken.
Ozone in the stratospheric ozone layer protects us from the sun's harmful rays.
But at ground-level, where we breathe it, it's not so good for us. In the summer,
sunlight and high temperatures 'bake' pollutants emitted by motor vehicles, power
plants, industrial manufacturing and other sources to form high levels of ground-level
ozone, commonly known as smog.
Particle pollution is the term for tiny drops
of liquid or small particles of dust, metals and other material that float in the
air. Some particles are large or dark enough to be seen as soot or smoke. Others
are so small that they can only be detected with an electron microscope. Particle
pollution comes from a variety of sources such as cars, power plants, factories,
construction sites, forest fires, and municipal waste incinerators.