State of Environment Reporting

Air Quality in British Columbia

Percentage of Monitored Communities Exposed to Human Health Risks from Fine Particulates for more than 18 days, or 5% of the time.

SOURCE: BC Ministry of Water, Land and Air Protection, 2001, Air Resources Branch. NOTES: This indicator depicts the percentage of communities where PM10 is greater than 25µg/m³, the concentration above which there is statistical evidence that health risks begin to occur, for more than 5% of the time in each year. Data were taken from two types of stations – continuous and non-continuous. Non-continuous samplers take samples over a 24-hr period once every six days. Only stations with data for 75% of the hours over each quarter of the year were included. The total number of stations meeting these requirements were 1994, 19; 1995, 24; 1996, 27; 1997, 32; 1998, 32; 1999, 36; 2000, 38. Monitoring stations are often located in communities where air quality is of some concern, therefore the data do not necessarily reflect the average air quality. In cases where there was more than one monitor in a community, the monitor located in a residential areas or city centre was chosen over monitors located adjacent to industrial facilities.

Status and trends in fine particulates (PM₁₀) in British Columbia

• Fine particulate matter (PM) includes naturally occurring dust as well as soot, smoke, liquid droplets and other particles emitted by vehicles, factories, power plants, construction and other human activities.
  
  
• In 2000, 25 out of 40 communities monitored exceeded the fine particulate (or PM₁₀) levels at which health risks are known to occur, on more than 18 days (or 5% of the time). Twenty-one of these communities exceeded this level on more than 36 days (or 10% of the time).
  
  
• Air quality appears to be improving in several communities. For example, twelve communities have shown consistent improvements in the concentrations of PM₁₀ over the past three years.
  
  
• This indicator uses 25 micrograms per cubic metre as the concentration where health risks begin to occur. Studies have not been able to determine a threshold below which there are no health effects. People with respiratory and cardiovascular ailments may be exposed to health risks at concentrations below 25ug/m³.
  
  
• PM is divided into classes depending on particle size. PM₁₀, measured in this indicator, refers to particles 10 micrometres or less (about 1/8th the width of human hair). Studies suggest that a smaller particle (PM_2.5) poses a greater human health risk than PM₁₀.

Why is it important?

• Fine particulates (PM₁₀ and PM_2.5) can pose a serious threat to public health. Most at risk are individuals with chronic obstructive pulmonary or cardiovascular disease, asthmatics, the elderly and children.
  
  
• Fine particulates are a major component of smog.
  

• Initiatives designed to protect good air quality, and improve on poor air quality, include: the development of a framework for airshed planning that can be applied to threatened airsheds; the development individual airshed management plans in Prince George, the Bulkley Valley, Greater Vancouver, Quesnel/Williams Lake, Golden and the Fraser Valley; Air Care, an ongoing inspection program to reduce motor vehicle emissions in the Lower Fraser Valley, a heavy vehicle testing program in the Lower Fraser Valley; modernization of air monitoring programs; continued phase-out of beehive burners; and Smoke Control Regulations such as the regulation of large-scale open burning and higher standards for wood stoves.