Air pollution has been associated with significant adverse health effects, including increased morbidity and mortality. The global increase in the prevalence of diseases that are associated with exposure to air pollution is of great concern. In particular, severe PM2.5 pollution occurs in Asian countries due to increasing emissions of air pollutants caused by the countries' rapid economic growth. A number of studies have been performed to clarify the association between PM2.5 and disorders such as asthma, ischemic cardiovascular diseases, arteriosclerosis, cancer, and neurological disorders. It is important to protect populations that are susceptible to such pollution. While the characterisation and monitoring of pollutant components currently dictates pollution control policies, it will be necessary to identify susceptible populations in order to adequately target prevention strategies for the health effects of air pollution. This book offers a comprehensive review of the recent advances in our understanding of the health effects of PM2.5, the role of oxidative stress in these effects, the contribution of ultrafine fractions of PM2.5 to the health effects, and discusses prevention strategies for these health effects. It also suggests further risk assessment, risk management, and novel policies for PM2.5 pollution, required to protect public health.