Pollution could be causing up to 25,000 premature deaths in Canada each year and burdening the health care system with up to $9.1-billion annually in extra costs, according to a new study by researchers at the University of British Columbia and the University of Alberta.

The study is one of the first to estimate the largely preventable health toll in Canada caused by the widespread exposure to air pollution, hazardous chemicals and pesticides, although the World Health Organization has conducted similar research this year and also concluded that environmental factors cause thousands of premature deaths in Canada each year.

The research was published online this week in the journal Environmental Research, and also estimated that pollution is responsible for between 8,000 and 24,000 new cases of cancer and 500 to 2,500 low birth-weight babies annually.

The estimated health toll from environmental causes is a controversial subject and hard to calculate precisely, but is based on research indicating that a portion of such common illnesses as cancers, respiratory diseases and heart problems are linked to pollutants.

Comment: Interesting how cancer, respiratory diseases and heart problems can be caused by environmental factors. Yet we are relentlessly pushed by the media to think smoking is the only cause.

The lead author of the study says the findings highlight that Canada could improve its health standards by implementing more stringent regulations to control environmental hazards.

"In our cultural DNA, we think of Canada as a pristine nation, but this is at odds with our track record on the environment," said David Boyd, an environmental lawyer and PhD candidate at UBC's Institute for Resources, the Environment and Sustainability who co-authored the paper with University of Alberta medical professor Stephen Genuis.

The two researchers used recent public health data to estimate the deaths caused by exposure to environmental hazards in four categories: respiratory disease, cardiovascular disease, cancer and congenital afflictions.

"We focused on these diseases because there is strong evidence connecting them to environmental contaminants," Mr. Boyd said.

Mr. Boyd said Canada could cut the toll caused by pollution by developing stronger environmental standards for air quality, drinking water, food and consumer products. He also says Canada needs to invest more resources in research, health tracking, and the development of greener technologies, as is done in some European countries.

"Sweden ... is light years ahead of Canada, so that would be a good place to start," Mr. Boyd said. "They have the substitution principle, whereby if there is a safer chemical available, there is legal obligation to use the safer one."

The study estimated that pollution causes about 1.1 million to 1.8 million restricted activity days for asthma sufferers each year and causes Canadians as a group to spend from 600,000 to 1.5 million extra days a year in hospital.