Air quality in Canada

For millennia, changes in the earth's atmosphere were the result of natural forces. Over the past century, however, these changes have escalated as a result of human activities-mainly unprecedented growth in global population and consumption of natural resources to increase industrial production-that degrade and destroy the forests and other vital ecosystems essential to atmospheric processes. Such human activities produce large quantities of substances that are released in the air, where over time they can overload natural processes and eventually reach harmful levels. The result is poor air quality in urban and rural areas around the world.

This article addresses the following questions: What is the condition of our outdoor and indoor air? What effects does air quality have on our health and our environment? And what are governments and businesses doing to address air quality concerns?