Dr. TANG Ning at Division of Atmospheric Environmental Studies clarified the behaviors of atmospheric polycyclic aromatic compounds in Beijing, China, and published the paper in Atmospheric Environment, volume 152.

Most of polycyclic aromatic hydrocarbon (PAH) and nitropolycyclic aromatic hydrocarbon (NPAH) are mutagenic and/or carcinogenic. In this study, nine PAHs and five NPAHs in the atmosphere in Beijing, the capital of China, were investigated from 2004 to 2010. Both the concentrations of PAHs and NPAHs decreased in the non-heating season but only the concentrations of NPAHs decreased in heating season. These findings suggest that source control measures implemented by the city of Beijing helped to reduce air pollution in Beijing. The concentrations of PAHs increased in 2010, possibly because of the transport of emissions from windward other areas, such as Shanxi province. Several diagnostic ratios of PAHs and NPAHs showed that the different sources contributed to Beijing’s air pollution, although coal combustion was the main source in the heating season and vehicle emission was the main source in the non-heating season. An analysis of physical parameters in Beijing showed that high wind speed can remove atmospheric PAHs and NPAHs in the heating season and that high relative humidity can remove them in the non-heating season.

Journal title: Atmospheric Environment
Title: Atmospheric behaviors of particulate-bound polycyclic aromatic hydrocarbons and nitropolycyclic aromatic hydrocarbons in Beijing, China from 2004 to 2010
Authors: Tang, N., Suzuki, G., Morisaki, H., Tokuda, T., Yang, X., Zhao, L., Lin, J., Kameda, T., Toriba, A., Hayakawa, K.