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.

How does this affect me?

Why is PM_2.5 Important?

Fine particles are a major component of haze and contribute to reduced health, visibility, safety, aesthetics and tourism. The smaller particles that comprise PM_2.5 contribute greatest to haze, as they are more efficient at scattering light than larger particles.

Human Health Effects

Small airborne particles can pose a significant risk to human health. They can be inhaled deeply into the lungs and penetrate the respiratory system. They can then affect breathing, aggravate existing respiratory and cardiovascular diseases, damage lung tissue and contribute to premature death. Once these particles are lodged in the lower regions of the lung, they are difficult to remove through coughing or sneezing and are of particular concern for people with chronic heart and lung disease, as well as for children and the elderly.

The incidences of asthma and other lung related conditions have increased dramatically in the last decade. The BC Lung Association reports that in Canada, 10 to 15 percent of children now have asthma. This staggering statistic is also true on the other side of the border; research from the American Lung Association shows that one in ten children in Washington are affected by asthma.

Graphic: How deeply can particles be inhaled in the lungs?

Source: Environment Canada

Exposure to PM_2.5 leads to cardiovascular and respiratory effects such as:

• Asthma
• Bronchitis
• Emphysema
• Pneumonia
• Premature deterioration of the lungs
• Coronary artery disease
• Abnormal heart rhythms
• Congestive heart failure
• Increased risk of lung cancer⁶

Populations of Risk

Certain populations, such as the elderly, people with existing lung or heart conditions, and children are more vulnerable to the effects of PM_2.5.

Elderly individuals: The EPA estimates that tens of thousands of older adults die prematurely each year because of exposure to fine particles. Since many elderly individuals suffer from preexisting heart and lung conditions, they are especially vulnerable to the health effects of PM_2.5.

People with preexisting heart and lung conditions: Exposure to PM_2.5 leads to increased hospital admissions and medical treatment and is linked with premature death in this population.

Children: Children breathe 50 percent more air per pound of body weight than adults, who already breathe more than 11,000 liters of air per day. In addition, children's respiratory systems are still developing. Exposure to PM_2.5 causes reduced lung function, increased school absences, the inability to engage in children's activities such as sports, and may affect the long-term development of healthy lungs.

Asthmatic adults and children: In Washington State, 11 percent of adults and 10 percent of children have asthma. In British Columbia, almost eight percent of the population has asthma, leading to 27,646 hospital day stays each year. PM_2.5 exposure aggravates asthma and leads to more frequent medical treatment and hospital visits.^7,8

Diesel Particles and Surface Area
Diesel particles have a large surface area, similar to the way you might envision a big VelcroTM ball. Because of their large surface areas, these particles can carry great amounts of organic materials on their surfaces through adsorption.

Cancer Risk, Carbon and Diesel Particulate

Organic material identified in diesel exhaust emissions includes hydrocarbons and their derivatives, polycyclic aromatic hydrocarbons (PAHs) and heterocyclic derivatives.⁹ Many PAHs are known cancer-causing agents because they interact directly with DNA.

PAHs were also among the first substances to be associated with cancer profiled in European coal tar workers in the late 1800s. PAHs can adversely affect survival, growth, metabolism, reproduction and immune function. It is hypothesized that the presence of the adsorbed chemical may influence particle toxicity through certain mechanisms by which a substance's effect is worsened by interaction with other substances.¹⁰

Economic Costs

In British Columbia alone, increased hospital stays from asthma cost approximately $15 million. A recent Lower Fraser Valley (LFV) study estimated that because PM_2.5 exposure leads to health effects at every level, changes in ambient air quality of one percent will lead to $29 million in annual savings. Conversely, it costs nearly $223 million each year in the LFV in PM_2.5 associated costs.¹¹

Asthma, one effect from PM_2.5 exposure, costs Washington State over $400 million each year, including over $100 million in prescriptions alone.

Loss of Tourism Revenues from Impaired Visibility

Haze is created when sulfur and nitrogen oxides (SOx and NOx) and particulate matter scatter light. The smaller particles that comprise PM_2.5 contribute greatest to haze, as they are more efficient at scattering light than larger particles. Haze impairs visibility and our ability to see our beautiful vistas. It is these vistas, in conjunction with the overall beauty of the region that draws people to live, do business in and visit the Puget Sound-Georgia Basin.

In 2000, a study sponsored by the Georgia Basin Ecosystem Initiative was released showing a correlation between poor visibility and loss of tourism revenue.¹²

The study estimated the impact of poor visibility episodes on tourist revenue in Greater Vancouver and the Lower Fraser Valley. It involved an interactive survey with visiting tourists, statistical analysis of the results and constructing an economic model to predict losses in tourist revenue from selected poor visibility episodes. For just one poor visibility event, the model predicts future tourist revenue losses of $7.45 million in the Greater Vancouver area and $1.32 million in the Fraser Valley.

In the Greater Vancouver Regional District/Fraser Basin Valley, researchers found that nitrous oxide, which appears orange-brown on the horizon, interacts with ammonia from agricultural production to reduce visibility. Secondary particulate formation then forms ammonium salts, scattering light and forming a white haze.

Fine Particles (PM2.5) and Visibility in Abbotsford, British Columbia
Good Visibility Day (PM2.5=3µg/m3)		Poor Visibility Day (PM2.5=8µg/m3)
Fine Particles (PM2.5) and Visibility in Seattle, Washington
Good Visibility Day (PM2.5=5µg/m3)		Poor Visibility Day (PM2.5=30µg/m3)

 

 

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