Air Quality
This indicator examines trends in air quality related to the concentrations of fine particulate matter in the Puget Sound Georgia Basin. Fine particulate matter is one component of air quality, chosen because of its effect on human health and visibility.

What is happening?

Georgia Basin

PM_2.5 data was collected between 1996 and 2004 at 11 locations throughout the Georgia Basin. Locations include not only urbanized areas such as Vancouver and Victoria, but also less commercial locations such as Powell River and Whistler.

Click on the image at right to see a larger version of "Air Quality Stations in Georgia Basin & Puget Sound."
Source: Environment Canada

Measuring PM_2.5 against Canadian Federal Standards

PM_2.5 is measured against the Canada Wide Standard (CWS) for Particulate Matter and Ozone. The standard for PM_2.5 is 30 µg/m3 averaged over 24 hours. Canada Wide Standards are set by Canadian federal organizations. BC will be responsible for meeting these standards by 2010. The main goal of this standard is to minimize the negative impacts of both particulate matter and ozone on human health and the environment. This particular CWS considers both pollutants together because they share common sources and contribute to smog.²

Standards for the Greater Vancouver Regional District

The Greater Vancouver Regional District (GVRD) adopted a 24-hour objective, or standard, for particulate matter at 10 micrometers, or PM₁₀, in 1994. All GVRD air quality objectives are currently under review as part of the Air Quality Management Plan review. However, there are currently no short term objectives for PM_2.5. There is, however, a proposed 24-hour objective of 25 µg/m3 and an annual air quality objective of 12 µg/m3.

Chart: How PM_2.5 is Measured in Canada and the U.S.

PM2.5 Measurement
Agency	Standard
Canada
The Canadian Council of ministers of the Environment (CCME)	30 µg/m3 (24-hour average, 3-year average of the 98th percentile measured annually)
National Ambient Air Quality Objectives (NAAQO)	n/a
BC Ministry of Environment (Level B)	As per Canada-Wide Standard
Greater Vancouver Regional District*	As per Canada-Wide Standard
United States
U.S. EPA National Ambient Air Quality Standards	65 µg/m3 (24-hour average, 3-year average of the 98th percentile of 24-hour concentrations) 15 µg/m3 (Annual average, 3-year average of the weighted annual mean of PM2.5 concentrations)
Washington Department of Ecology	As per EPA Standards
Northwest Clean Air Agency	As per EPA Standards
Puget Sound Clean Air Agency	As per EPA Standards

Puget Sound

The United States Environmental Protection Agency (US EPA) established a federal 24-hour standard for PM_2.5 at 65 µg/m3. The annual standard for PM_2.5 is 15 µg/m3. The standard for PM_2.5 sets limits to protect public health, including the health of "sensitive" populations such as asthmatics, children, and the elderly. The standard also serves to protect public welfare, including protection against decreased visibility, damage to animals, crops, vegetation, and buildings.

The Puget Sound Clean Air Agency, one of Washington's regional air authorities, has adopted a goal of maintaining PM_2.5 levels in the Puget Sound region at or below a 24-hour average of 25 µg/m3.

Results for the Puget Sound Georgia Basin

The levels of PM_2.5 in the Puget Sound ecosystem have gradually decreased since the early 1990s. The Puget Sound region currently meets the National Ambient Air Quality Standard for PM_2.5. In the Georgia Basin, concentrations have remained relatively steady over the same period. PM_2.5 is forecasted to increase over 19 percent in Puget Sound between 1996 and 2018, and 10 percent in the Lower Fraser Valley between 2000 and 2020.³

PM_2.5 Puget Sound Region Annual Averages

Click on the graph to view a larger version.
Source: EPA, Washington State Department of Ecology

The graph at right reveals the average annual concentrations of PM_2.5 in the Puget Sound region from 1999 to 2004. The U.S. annual standard for PM_2.5 (15 µg/m3) is indicated by the red line marked "Federal Standard."

 

PM_2.5 Maximums and Averages in the Georgia Basin

Click on the graph to view a larger version.
Source: Environment Canada

The graph at right pertains to the PM_2.5 Maximums and Averages in the Georgia Basin.²⁵ In the Georgia Basin, PM_2.5 values have been relatively constant since the mid-1990s (graph at right). Here, "annually averaged hourly measurements" are represented by the orange line and the "annual average of daily maximum" values are shown by the blue columns.

Ambient Levels of PM_2.5 Against the Canada-Wide Standard

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Source: Environment Canada

As shown in the image at right, all measured communities in the Georgia Basin are below the Canada-Wide Standard (CWS) for PM_2.5 (depicted by the black bar on the left-hand side of each plot).²⁶

How does it compare to other areas?

While the Georgia Basin is the most populated area of BC, communities in this area are often not exposed to the high concentrations of PM_2.5 seen in other areas of the province. This is because the level of fine particles in the air is determined by many factors, including the number of older wood stoves, the amount of outdoor burning in the area, as well as weather conditions and the overall influence of terrain on the dispersion of pollutants.

PM_2.5 concentrations in Puget Sound are comparable with other areas of Washington State, although the sources of particles are different. Communities east of the Cascade Mountains show occasional higher peaks of fine particles from large-scale agricultural burning or wind blown dust. These, however, are not significant sources in the immediate Puget Sound region. The average levels of PM_2.5 do tend to be higher in urban or industrialized areas.

 

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