Indoor Air Pollution From Household Fuel Combustion In China: A Review
Nearly all China’s rural residents and a shrinking fraction of urban residents use solid fuels (biomass and coal) for household cooking and heating. As a result, by use of global meta-analyses of epidemiological studies, it is estimated that indoor air pollution from solid fuel use in China is responsible for ~ 420,000 premature deaths annually, more than the ~300,000 attributed to urban outdoor air pollution in the country. To help elucidate more fully the extent of this hazard, we reviewed nearly 200 publications reporting health effects, emission characteristics, and/or indoor air concentrations associated with the use of solid fuels, mainly coals, in both rural and urban areas of China. Health effects include cancer (mainly lung cancer), chronic obstructive pulmonary diseases, respiratory illnesses, immune system weakening, and lung function reductions. Arsenic poisoning and fluorosis, resulting from coal combustion, have also been observed. Although attempts have been made in a few studies to identify specific coal smoke constituents responsible for specific adverse health effects, the majority of indoor air measurements include only particulate matter, carbon monoxide, sulfur dioxide, and/or oxides of nitrogen. Based on the measurements made in 122 individual studies, we summarize the distributions across residences from 29 provinces, showing indoor concentrations exceeding health-based standards in many of the measured households. Finally, we review various past and potential intervention options including the National Improved Stove Program and several emerging fuel technologies.