Epidemiologic studies of particulate matter and lung cancer.

Particulate matter (PM) plays an important role in air pollution, especially in China. European and American researchers conducted several cohort-based studies to examine the potential relationship between PM and lung cancer and found a positive association between PM and lung cancer mortality. In contrast, the results regarding PM and lung cancer risk remain inconsistent. Most of the previous studies had limitations such as misclassification of PM exposure and residual confounders, diminishing the impact of their findings. In addition, prospective studies on this topic are very limited in Chinese populations. This is an important problem because China has one of the highest concentrations of PM in the world and has had an increased mortality risk due to lung cancer. In this context, more prospective studies in Chinese populations are warranted to investigate the relationship between PM and lung cancer.