Sea-to-Sky Airshed Ambient Air Quality Monitoring Report 1984 - 2001
The Sea-to-Sky Airshed includes the areas of Howe Sound (including Langdale and Horseshoe Bay) up through Squamish, Whistler and the Pemberton Valley. The southern half of this airshed has historically been the more industrialized portion, and includes two pulp mills. The northern half of the airshed is dominated by a mountain tourist resort and outdoor recreation pursuits. In general, the air quality in the Sea-to-Sky Airshed is "good" (using the BC Air Quality Index ratings of "good", "fair", "poor", "very poor") and well below national and provincial Air Quality Objectives. In summer, however, air pollutant concentrations regularly reach the "fair" category and, on rare occasions when weather conditions are particularly stagnant, conditions have reached into the "poor" category. Over the past two decades, concentrations of some pulp mill related pollutants have decreased somewhat, but in general, pollutant concentrations have remained the same.
Historically, air quality was measured only in the southern half of the Sea-to-Sky Airshed due to the presence of the pulp mills at Port Mellon and Woodfibre. The main pollutants of concern with respect to pulp mill emissions are: total reduced sulphur (TRS) which is associated with odour, sulphur dioxide (SO2) which is associated with airway inflammation and nose and throat irritation, and particulate matter (PM10) which is associated with adverse effects on respiratory and cardiac systems. Since the 1980s (when continuous measurements first began), the number of hours per year where the TRS odour levels have reached the "fair" category has decreased, although the monitoring technology has changed over the past two decades, making it difficult to directly compare longer-term averages. Levels of SO2 (always in the "good" category) and PM10 (usually "good", 10% "fair") have remained similar over the past twenty years.
Two pollutants which are of concern with respect to present and future air quality in the Sea-to-Sky Airshed are ground-level ozone (O3) and particulate matter (PM10 and PM2.5). In the summer, concentrations of both of these pollutants contribute to occasional events of "fair" and "poor" air quality. These two pollutants are associated primarily with vehicle emissions, as well as industrial emissions. Due to the rapid growth that is already a reality in the corridor, and the growth that is predicted in the coming decades, these pollutants have the potential to increase, and will be closely monitored for future reporting in the Sea-to-Sky region.
The The Sea-to-Sky Airshed Ambient Air Quality Monitoring Report is available here
(PDF/939KB/93 pages).
|
