This combustion is the problems small dust and harmful gases such as sulfur dioxide, nitrogen dioxide, carbon monoxide, and. In the atmosphere and spread to an area of the community. Smog pollution in the North as a major air pollution problem, one of the country's problems. The terrain is the swamp for the Pan and the climate in the winter with high air pressure. Weather and dry for a long time. Allow the accumulation of pollutants in the atmosphere exceeded these standards.