Most air pollutants are damaging to human health. Whilst high profile air pollutants such as sulphur dioxide, carbon monoxide and ground level ozone are present in the Williams Lake Airshed, it is the high levels of suspended particulate matter (PM) that pose the greatest problem. PM10 refers to particulate matter less than 10 micrometers (μm) in diameter, these relatively small particles can remain in the atmosphere for long periods of time and they are capable of traveling large distances from their source. Particles less than PM10 are also known as inhalable particles, they can be breathed into the lungs and as a general rule the smaller the particle the deeper they penetrate.
Inhaled pollutants irritate, inflame or destroy lung tissue. Studies in B.C. associate at least 82 deaths annually with inhalation of fine particulate matter. Inhalation of particulate matter exacerbates heart and lung conditions and increases hospitalization of those suffering from chronic respiratory disorders such as asthma, bronchitis and emphysema.
Particles less than 2.5μm are thought to be especially harmful as they penetrate to the deepest regions of our lungs. Composed mainly of secondary particles (formed from physical and chemical reactions involving gases such as oxides of nitrogen, sulphur and ammonia, and volatile organic compounds (VOCs) there are a growing number of studies linking these smaller particles with premature death.
Suspended particulate matter is too small to register with the naked eye, however, it is clearly visible in our airshed when atmospheric concentrations reach sufficient levels to form a blue or brown haze. Sources of particulate matter vary from naturally occurring dust pollen and spores, to those originating from human activity such as industrial processes, back yard burning, home and commercial heating, car and truck emissions, and road and construction dust. Whilst the natural sources of particulate matter are difficult to control, we can however influence human sources: we can make a difference.
Monitoring stations in Williams Lake continuously sample ambient air for fine
particulates less than 10 and 2.5 micrometers in diameter.
