The quality of the air we breathe is important to Albertans. Over the last two decades, there has been increased public awareness about issues such as urban smog, acid rain and global warming. Also, there have been many advances in air pollution reduction technology that have led to a decline in emissions of a number of pollutants since the 1970s. However, Albertans are still concerned about the quality of our air and what contaminants are being released. As technology improves, we are able to better track quantity of emissions released into the atmosphere and the quality of the air. The more we learn about our environment and our impact on it, the better able we are to make informed choices about how to improve air quality both from a society and individual basis. The quality of the air we breathe is dependent on the rate that pollutants are emitted into the atmosphere and the ability of the atmosphere to disperse these pollutants. The movement and dispersion of air pollutants is controlled by wind, temperature, turbulence and the changes in these elements caused by local topography.