A Health Risk Assessment of Carbonyl-containing Volatile Organic Compounds in the Atmosphere of Chinese Megacities

Carbonyl-containing volatile organic compounds (cVOCs) are important precursors of atmospheric photochemical reactions in the formation of ozone, smog and other air pollutants. China’s megacities are economically developed and densely populated metropolitan areas, usually with a population over ten million; they drive the rapid growth of surrounding urban clusters. So far, 21 cVOCs have been detected in the atmosphere of these megacities. The average annual total concentration of cVOCs is 55.6 μg/m3, an alarmingly high level. Vehicle emissions, industrial discharges, excessive use of organic solvents and other factors have led to a situation where hazardous formaldehyde, acetaldehyde and acetone account for 62.4 percent of the total atmospheric concentration of cVOC in Chinese cities. In a quantitative evaluation using daily exposure levels, cancer risk and hazard quotient, we found that the excessive levels of atmospheric cVOCs in Beijing, Shanghai and Guangzhou pose serious health risks to their inhabitants. Air pollution persists, despite the brief improvements in air quality brought about by the air quality campaign undertaken during major international events like the 2008 Olympic Games, the 2010 Asian Games, and the 2010 World Expo. The health risks caused by atmospheric cVOCs in Chinese cities require close attention.