Degradation of PAHs during long range transport based on simultaneous measurements at Tuoji Island, China, and at Fukue Island and Cape Hedo, Japan

Kojiro Shimada; Masayuki Nohchi; Xiaoyang Yang; Taichi Sugiyama; Kaori Miura; Akinori Takami; Kei Sato; Xuan Chen; Shungo Kato; Yoshizumi Kajii; Fan Meng; Shiro Hatakeyama

doi:10.1016/j.envpol.2019.113906

Degradation of PAHs during long range transport based on simultaneous measurements at Tuoji Island, China, and at Fukue Island and Cape Hedo, Japan

Environ Pollut. 2020 May:260:113906. doi: 10.1016/j.envpol.2019.113906. Epub 2020 Jan 10.

Authors

Kojiro Shimada¹, Masayuki Nohchi², Xiaoyang Yang³, Taichi Sugiyama⁴, Kaori Miura⁵, Akinori Takami⁶, Kei Sato⁶, Xuan Chen⁷, Shungo Kato⁸, Yoshizumi Kajii⁹, Fan Meng⁷, Shiro Hatakeyama¹⁰

Affiliations

¹ Global Innovation Research Organization, Tokyo University of Agriculture and Technology, 3-5-8 Saiwaicho, Fuchu, Tokyo, 183-8509, Japan; School of Creative Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo, Japan.
² School of Creative Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo, Japan.
³ State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, 8 Dayangfang, Beiyuan Road, Chaoyang, Beijing, 100012, China. Electronic address: yangxy@craes.org.cn.
⁴ Graduate School of Engineering, Kyoto University, Kyoto, 606-8501, Japan.
⁵ Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwaicho, Fuchu, Tokyo, 183-8509, Japan.
⁶ Center for Regional Environmental Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan.
⁷ State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, 8 Dayangfang, Beiyuan Road, Chaoyang, Beijing, 100012, China.
⁸ Department of Applied Chemistry, Faculty of Urban Environmental Sciences, Tokyo Metropolitan University, 1-1 Minami-oosawa, Hachioji, Tokyo, 192-0397, Japan.
⁹ Department of Natural Resources, Graduate School of Global Environmental Studies, Kyoto University, Yoshida-honmachi, Sakyoku, Kyoto, Kyoto, 606-8501, Japan.
¹⁰ Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwaicho, Fuchu, Tokyo, 183-8509, Japan; Center for Environmental Science in Saitama, 914 Kamitanadare, Kazo, Saitama, 347-0115, Japan; Present address: Asia Center for Air Pollution Research, 1182, Sowa, Nishiku, Niigatashi, Niigata, 950-2144, Japan.

PMID: 31972416
DOI: 10.1016/j.envpol.2019.113906

Abstract

We investigated the degradation of polycyclic aromatic hydrocarbons (PAHs) during long-range transport. Aerosols were collected simultaneously at remote sites on Tuoji Island, China; Fukue Island, Japan; and the Cape Hedo Atmosphere and Aerosol Measurement Station (CHAAMS), Okinawa, Japan in April, October, and December from 2012 to 2013. These remote sites were convenient for investigating the degradation of PAHs during long-range transport. PAHs were analyzed via gas chromatography/mass spectrometry. We identified air masses that passed over all sites and combined our measurements with a chemical transport model. We estimated the relative contributions of the PAHs at the three sites by normalizing the PAH concentrations to elemental carbon. Benzo[a]pyrene persisted in 5-16% of samples. The results of this study are consistent with laboratory studies in which secondary organic aerosol (SOA) coatings protected PAHs from degradation by ozone. We detected an inhibition of the degradation PAHs by SOA coatings by collecting PAHs simultaneously at the three sites. To elucidate the major sources of the SOAs, we carried out a positive matrix factorization analysis to identify the major sources of SOA coating, which controls the lifetime of PAHs. In spring and winter, the contribution of vehicle emissions was higher (46%) at Tuoji Island than at CHAAMS (13%). In contrast, the contribution of coal combustion was higher at CHAAMS (59%) than at Tuoji Island (28%). This result implies that during long-range transport, PAHs derived from coal combustion are more slowly degraded than PAHs derived from vehicle emissions. We found that the viscosity of SOA coatings derived from vehicle emissions in China was low, and the corresponding PAHs were rapidly degraded. In contrast, the viscosity of SOA coatings derived from coal combustion was high, and degradation of the corresponding PAHs was relatively slow. These results imply that PAHs derived from coal combustion have long lifetime.

Keywords: CHAAMS; Coal combustion; PAH degradation; PAHs; Tuoji Island.

MeSH terms

Air Pollutants* / analysis
Air Pollutants* / metabolism
China
Coal
Environmental Monitoring*
Islands
Japan
Polycyclic Aromatic Hydrocarbons* / analysis
Polycyclic Aromatic Hydrocarbons* / metabolism
Seasons

Substances

Air Pollutants
Coal
Polycyclic Aromatic Hydrocarbons