Tuesday, June 07, 2005

Smog kills 800 a year in Toronto

'Potentially avoidable': Heat-related deaths will double by 2050: study

A study attributes 1,082 deaths a year in Montreal to the effects of extreme heat, cold and air pollution.

More than 800 people die each year in both Toronto and Montreal from the acute effects of exposure to smog, a report released yesterday says.

The study found 822 smog-related deaths annually in Toronto, 818 in Montreal, 368 in Ottawa and 258 in Windsor.

"We've got hundreds of deaths that can be attributed to air pollution and the combined effects of air pollution and extreme temperature. Those are deaths that are potentially avoidable," said Dr. David McKeown, Toronto's Medical Officer of Health.

Based on their findings, Toronto Public Health researchers projected heat-related mortalities will double in the four cities surveyed by 2050 and triple by 2080. They also determined that deaths related to smog will increase by 20% by 2050 and 25% by 2080.

The study of the four cities -- done in conjunction with Environment Canada -- traced the impact of extreme heat, cold and air pollution on premature mortality rates over a 46-year-period.

Researchers cross-referenced hour-by-hour mortality and weather data between 1954 and 2000 along with air pollution data between 1974 and 2000.

The results suggest extreme heat days have mortality rates twice as high as normal days.

Dr. McKeown said Toronto had another 120 deaths linked to heat and 105 connected to extreme cold.

The release of the report came the same day as Toronto's first heat alert for 2005 and following a five-day long smog advisory declared by the Ministry of the Environment.

John Filion, the Toronto Board of Health chairman, said the study demonstrates pollution is a "serious health risk."

"If we had some catastrophe in Toronto where we could identify it caused 800 people to die prematurely, the public would pay attention," Mr. Filion said. "But because we don't know who those 800 people are, people tend to say, 'We don't need to be very concerned.' "

Dr. Quentin Chiotti, air program co-ordinator for Pollution Probe, said the report represented a significant step in recognizing heat and pollution-related deaths are interrelated. Studies in the past have tended to focus on one area or the other, he said.

"This study is the next generation that is beginning to show it's a combination of the two," he said.

Despite the study's grim findings, the researchers said air quality is better now than it was 20 years ago, with Environment Canada data suggesting levels of carbon monoxide and other pollutants have dropped since 1985. But Dr. Chiotti cautioned that while air pollution has diminished, increasing global temperatures will likely present new health risks. Nearly 11,000 deaths occurred in Europe during a heat wave in 2003.

"This is not a trivial problem," Dr. Chiotti said.

Heat alerts are issued in Toronto when there is a 65% chance that weather conditions could result in premature deaths. When they occur, the city takes measures such as activating an information line operated by the Red Cross and alerting 1,100 community agencies to take extra precautions with vulnerable individuals, such as the elderly and the homeless. Dr. McKeown urged the federal government to institute a national heat warning system similar to Toronto's program.

"We think there are avoidable deaths happening," Dr. McKeown said. "Clearly, the heat alert system is based on the monitoring of local weather, but we think it could be a national system."


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