Outdoor and Indoor air pollution in China is mainly due to direct combustion of coal for domestic heating and cooking purposes. In general, air pollution levels are more severe in the northern parts of the country, during the cold season and cooking hours than in the southern parts, during the warm season and non-cooking hours. The direct impact of air pollution on human health is increasing incidents of chronic respiratory disease in urban and rural residents, and even increased cases of lung cancer in nonsmoking women. With the purpose of controlling air pollution and improving environmental health, a series of laws, standards and regulations have been adopted over the last few years.
