And like a smaller, but growing, number of his fellow countrymen, Brown, 58, knows it is wise to take precautions before exploring the elements for a long period of time - in his case, four to five hours on the golf course.

"I certainly bring lots of water," says Brown, a native of New Zealand, "and I tend to play mid- or late-morning. And if there is a smog advisory, those are the days I try to avoid, because often I will come off the course feeling additionally fatigued."

Brown's decision is a wise one, since as every Canadian medical association warns us, the air we breathe might not be good for us. And that's not just a rule for urban centres like Vancouver, Toronto and Montreal. Fact is, even cottage country may have a hidden enemy in its midst, thanks to poor air quality.

There are a myriad of factors that demand that today we take extra precautions before enjoying the great outdoors, especially during our Canadian summer. This includes industrial and vehicle emissions, ground-level ozone - gas resulting from the merging of pollutants and sunlight - and our changing climate, which many tag as global warming.

With all of these dangers, fear of smog and dangerous air pollutants may scare you into permanent hibernation, but by taking extra care outdoors you'll have it made in the shade.

The 2008 Heart and Stroke Foundation Report Card on Canadians' Health reported that there are 6,000 additional deaths in Canada each year due to short- and long-term exposure to air pollution - with nearly 70 per cent of deaths coming in the form of cardio and cerebrovascular disease.

"Since the early 1990s, a growing body of evidence from Canada, the U.S. and Europe has documented increased rates of heart attack, and more hospitalizations for serious heart diseases such as heart failure, and stroke, after both short- and long-term exposure to polluted air," says Dr. Beth Abramson, Heart and Stroke Foundation spokesperson and cardiologist.

The Heart and Stroke Foundation says that while Canadians seem to make the connection between air pollution and some diseases, only 13 per cent associated heart disease with air pollution.

Environment Canada estimates that at least 30 per cent of Canadians are being exposed to higher than acceptable levels of fine particulate matter - particles in the air formed from gaseous air pollutants that interact with sun and water.

According to the Heart and Stroke Foundation report, British Columbia, Alberta, Ontario and Quebec received failing grades when it comes to fine particulate matter and heart health.

All of the agencies mentioned call for increased awareness of the dangers of poor air quality. The Heart and Stroke Foundation has called for the Air Quality Health Index (AQHI), which gives daily information about air quality, to be rolled out across Canada. Currently used in Toronto, Nova Scotia and B.C., the AQHI is a new system to measure air quality and its effects on lung health. It's the first index of its type in the world to be based on scientific health studies.

Environment Canada currently updates its Air Quality Index (AQI) on an hourly basis at smc.ec.gc.ca. The AQI measures the level of six major air pollutants, and gives a reading based on the pollutant that's at the worst level that day.

Yet, according to the Canadian Lung Association, only one-third of Canadians are familiar with the AQI. This is unacceptable, according to Dr. Menn Biagtan of the British Columbia Lung Association.

"It's important that all Canadians become familiar with the AQI. It's like a canary in the coal mine, but even better. The index gives you a heads-up when air quality is poor, so that you can take preventative action," she says.

The new AQHI will provide "a great improvement over existing air quality indexes," according to Kenneth Maybee, chair of environmental issues for the Lung Association, which has partnered with Health Canada and Environment Canada throughout the development process. Says Maybee, "(The AQHI) provides Canadians with another way that they can take action to protect their own health and the health of others in their care."

Biagtan warns, it's not just urban dwellers who are affected by air pollution. People living in rural areas and in cottage country can be affected by pollutants released hundreds of kilometres away that get blown by the wind.

"Sometimes people think they're not affected by air pollution because they can't see it in the air," says Biagtan. "But ground-level ozone, one of the main components of smog, is colourless. You may not be able to see it, but it can harm you."

New data released in early June by the Ontario Medical Association (OMA) shows that air pollution is a contributing factor in almost 9,500 premature deaths per year in Ontario.

Dr. Ken Arnold, president of the OMA, urges people to take the proper precautions when air quality is poor.

"The health impacts from smog range anywhere from itchy eyes and sore throats to respiratory and cardiac illnesses and even premature death," says Arnold. "It's important for those who may be more at risk from smog-related illness to consult their doctor on how they can stay protected."

OUTDOOR EXERCISE: IS IT SAFE?

In 2006, Toronto Public Health and Health Canada completed a study to identify convenient times of the day when it's safe for vigorous outdoor exercise. Examining Canada's largest city, the two groups found, not surprisingly, that pollution levels tend to be lowest overall before 7 a.m. and after 8 p.m.

In 2007, Ontario recorded 59 poor air-quality days. On days when air pollution is high, it is recommended to: