Smog is caused by combustion. The occurrence of wildfire was many times both locally and from neighboring countries. Burning leaves through the rest of agricultural materials to prepare the area for planting during the rainy season the burn area to benefit the store vegetables. These combustion problems small dust and harmful gases such as sulfur dioxide, nitrogen dioxide, carbon monoxide. 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.