Never before have Canadians been as concerned about clean air. The federal government estimates that air pollution causes 5,000 premature deaths in Canada each year. Environmental and public health advocates believe the number closer to 16,000. If they are right, air pollution is responsible for approximately forty premature deaths across Canada every day. The magnitude and complexity of the threats to our clean air are staggering. Some of these threats - including smog, acid rain, and hazardous air pollutants - tend to be local or regional in scope. Others - such as ozone layer depletion and...