FOCUS REVIEW

disease, and respiratory diseases, are the leading causes of morbidity and mortality worldwide. In Canada alone, chronic diseases account for 87 % of total disability and 89 % of all deaths (1). It is estimated that half of the Canadian population live currently with a chronic illness and more than 90 % of them have these three diseases (1). Chronic diseases develop typically over long periods of time and have multiple risk factors. The major causes of cardiovascular disease include high cholesterol, high blood pressure, and obesity (2-6). For lung cancer and respiratory disease, tobacco smoking and exposure to toxic chemicals are important risk factors (7-15). More recently, ambient air pollution has been implicated in increasing the incidence and mortality from lung cancer and from cardio-pulmonar