Air quality here one of B.C.’s best
January 02, 2008
Between 16 and 98 people a year die from fine particulate exposure in the B.C. Interior and North, according to a new study by doctors Catherine Elliott and Ray Copes.
Fine particulate – particles 2.5 microns and smaller, called PM 2.5 – enters the air primarily as a by-product of combustion – gasoline and diesel engines, wood burning, industrial processes and other sources. The study found Prince George had the highest PM 2.5 levels in the province.
“Most of the mortalities [from PM 2.5 exposure] happen in the Interior and North, even though most of the population is in the Lower Mainland,” Elliott said.
“We know that people die from short-term air pollution events. With exposure over the long term, the risk is much greater than over the short term.”
New long-term studies in the U.S. have tracked PM 2.5 exposure and mortality rates over an 18-20 year period, she said. Those studies have given doctors a much better understanding of what the long-term effects of PM 2.5 exposure are.
The study looked at PM 2.5 levels across the province and factored together a number of studies to create an average annual mortality rate of 61 in the North and Interior. Elliott said the methodology they used is the same used by the B.C. health officer, several European countries and the World Health Organization (WHO).
Air quality in Terrace and the Vancouver Airport were used as benchmarks to compare mortality rates in the North and Interior.
If all communities in the North and Interior had PM 2.5 levels equal to Terrace, there would have been approximately 263 fewer deaths from 2001 to 2005. If all communities had the same air quality as the Vancouver Airport, there would have been 127 fewer deaths.
Even with the best data, the 16 to 98 per year range, “represents the degree of uncertainty,” in the projections, Elliott said.
“Someone doesn’t come in and doctors say, ‘This person died of air pollution,’” she said. “The mortality that is most attributed is cardiovascular – heart attacks. Fine particulate gets into the arteries and causes inflammation.”
PM 2.5 can be absorbed into the bloodstream through the lungs, she explained.
The study makes a number of recommendations, Elliott said, and reducing the levels of PM 2.5 is number one.
“Any research should generate more questions. Particulate is sorted according to size,” she said. “What’s in these particles? Which particles are most dangerous? We need more information.”
On an individual level, residents in communities like Prince George should take good care of their heart and their lungs, she said.
“One of the huge cardiovascular risks is smoking,” she said. “Lead a healthy, active lifestyle. The WHO now recommends 60 minutes [of exercise], five days a week. The personal lifestyle factors are critical.”
Elliott is a family physician and medical resident training in community medicine. She spends half her time in Prince George and conducted the study with Copes while working at the B.C Centre for Disease Control.
Terrace Standard
