An overview of PM2.5 sources and control strategies

The new national ambient air quality standard for particulate matter is summarized, with emphasis on fine particles, or particulate matter with aerodynamic diameter less than 2.5 μm (PM2.5). Sources of ambient and indoor PM2.5 are summarized, followed by an overview of control strategies for both primary (directly emitted) particles and gaseous precursors of ambient particles. The role of future findings on the health effects of particles of different sizes or compositions is noted, as is the potential importance of controlling indoor exposures for susceptible people. EPA risk management research on sources and control options is summarized. The cost-effectiveness of prevention and control technologies for PM2.5 has not been well researched and documented. Optimum control strategies will likely include a variety of control options.