ABSTRACT
Background Heavy reliance on relatively uncontrolled coal combustion as a source of heat and power has created serious environmental problems in China-particularly in its coal-rich northern provinces. Particulate matter (PM) and sulfur dioxide (SO2) are the major pollutants of concern, although with recent progress in reducing PM emissions, attention is increasingly shifting to the control of SO2. In many urban areas, high SO2 concentrations-along with fine particles created by the atmospheric transformations of SO2 into sulfates-represent a serious public health threat.
