Smog-related premature deaths among seniors could increase by about 80 per cent over the next 20 years, Ontario doctors warned Monday.

The Ontario Medical Association made 20-year projections of the consequences of smog for the health-care system, in a report, entitled Smog's Excess Burden on Baby Boomers.

The report says premature deaths from smog will jump from 4,890 to 8,870 in 20 years — an increase of about 81 per cent.

"Contrary to popular belief, many of the smog illnesses and premature deaths are cardiovascular in nature, rather than respiratory," the report's authors noted.

Smog could harm not only seniors with a history of heart or lung problems, but also those who are healthy.

A 45-year-old man or woman who hits the golf course on a smoggy day may "have a very slight event in their heart which would ordinarily be trivial, but catapults forward into a cardiac arrest," Dr. Ted Boadway, a spokesman for the OMA, told CBC Radio's Metro Morning.

The nitric oxide in smog is toxic to heart muscle cells and arteries, and can indirectly promote clogged arteries, Boadway said.

Assuming no changes in air pollution levels over the coming years, the report predicts smog will have a major effect on health care because of the aging bubble of baby boomers.

Specifically, smog-related emergency room visits for seniors are expected to jump by almost 24,000 per year, compared with an increase of 4,000 visits for all other age groups combined, according to the report.

Part of the problem is Canada is a laggard in conservation and a leader in energy consumption, Boadway said.

He applauded the Ontario government's plans to close coal-fired power plants over pollution concerns, as well as federal moves to reduce sulphur in fuels.