This study is focused on the linkage between lung cancer incidence rates and PM 2.5 pollution. Researches conducted by leading research organizations in U.S. and Europe were reviewed and analyzed, and strong evidence exists that elevated fine particulate air pollution exposures are associated with significant increases in lung cancer mortality. The linkage between fine particulate air pollution and lung cancer motility is observed even after controlling for cigarette smoking, occupational exposure, and other risk factors. This finding is in alignment with observations in China which show an upward trend of lung cancer incidences coupled with a downward trend in the number of smokers. Currently, China lacks systematic research on the effect of PM2.5 on lung cancer. As a result, this paper investigated studies on the linkage between pollution and lung cancer incidence from decades of research conducted in the U.S. and Europe. One important step in solving this issue in China is through classifying PM 2.5 pollution as a human cacinogen. Adequate government regulation, public awareness, regional collaboration and industrial compliance are also key to the successful control of PM 2.5 pollution and smog.

The increased occurrence of smoggy days in major Chinese cities is of major concern to the general public. This paper explores the major sources of PM 2.5 pollutants, a key contributor to the smog in Beijing, one of China's largest cities. Evidence indicates that the secondary PM 2.5 particles formed through NO x , SO x , NH 3 , VOCs, etc. have a strong impact on human health. As a result, PM 2.5 pollution control should not simply focus on controlling particulate emission, but should involve adopting an integrated multi-pollutant control strategy. In addition to identifying the major sources of PM 2.5 , this paper explores its impact on environmental and human health. Although the intention of this research is not to provide solutions for reducing PM 2.5 pollution, the paper analyzes the United States' experience with establishing PM 2.5 standards and mandates. Specifically, this paper focuses on the air quality control strategies adopted in California since the 1940s and draws parallels with present-day China. The research suggests that adequate government regulation, public awareness, regional collaboration and industrial compliance are keys to successfully controlling PM 2.5 pollution.