Developing a new paradigm for managing fine particulate air pollution.
Annette C. Rohr is program manager for air quality, health, and risk assessment at the Electric Power Research Institute (EPRI), and Ronald E. Wyzga is a senior technical executive and biostatistician at EPRI.
Fine particulate matter—particles less than 2.5 micrometers in diameter, or PM2.5—has been linked with a number of adverse health effects, including premature mortality, cardiovascular disease, and respiratory diseases such as asthma. PM2.5 is a complex mixture comprised of hundreds of different components, both inorganic and organic. Inorganic components include sulfate and nitrate—formed from gaseous sulfur dioxide (SO2) and nitrogen oxides (NOx)—as well as elemental species such as selenium, mercury, arsenic and chromium. Coal-fired power plants are the most significant source of SO2, while traffic is responsible for most NOx. Organic PM components include polycyclic aromatic hydrocarbons and a host of other compounds. These organic materials are derived from a variety of sources, including traffic and wood smoke, and from reactions between emissions of volatile organic compounds (VOC) from anthropogenic and natural vegetative sources and other atmospheric constituents. Black carbon (BC)—sometimes referred to as soot—is found primarily in tailpipe emissions, especially those from diesel vehicles, and wood smoke. BC is a significant contributor to ambient PM in urban areas.