Professor Emeritus, Institute of Nature and Environmental Technology, Kanazawa University, Japan

Speech Title: Recent Atmospheric Polycyclic Aromatic Hydrocarbons Pollution in the Far-Eastern Asian Context

Abstract: The combustion of fossil fuels and biomass produces many kinds of air pollutants such as CO₂ SO_x, NO_x, polycyclic aromatic hydrocarbons (PAHs) and nitropolycyclic aromatic hydrocarbons (NPAHs). In urban air, fine particulate matter (PM2.5) contains large amounts of PAHs and NPAHs. Benzo[a]pyrene, as a representative PAH, is classified as a Group 1 compound (carcinogenic to humans) and 1-nitropyrene (1-NP) is classified as Group 2A (probably carcinogenic to humans). Recently, the WHO classified outdoor air pollution, as well as PM2.5 into Group 1 [1]. Furthermore, several PAHs and NPAHs show not only carcinogenicity/mutagenicity but also endocrine- disrupting and reactive oxygen species-producing activities [2, 3]. To understand recent urban pollution in Far-Eastern Asia caused by combustion-based PM2.5, urban PM was collected in the summer and winter in Japan, China, Korea and Far-Eastern Russia between 1997 and 2014. PAHs and NPAHs were respectively determined using HPLC methods with fluorescence and chemiluminescence detections, respectively [4].

The comparison of atmospheric PAH and NPAH concentrations and compositions revealed the following characteristics of the cities. (1) Concentrations of PAHs and NPAHs were still much higher in China (especially during the winter in northern cities such as Shenyang and Beijing) and Russia than Japan and Korea. (2) PM emitted from low-temperature combustion such as coal heating consisted of large percent of the total PM in winter in Shenyang. (3) PM containing PAHs and NPAHs emitted in China was long range transported to Japan [5]. (4) Japanese commercial cities showed a significant decrease in PAH and NPAH concentrations with decreases in the [NPAH]/[PAH] ratio, suggesting that countermeasures against PM/NOx emissions from automobiles were effective [6].

References
[1] IARC Monographs, Vols. 1–116 (2016).
[2] Hayakawa, K. et al, J. Health Sci., 53, 562 (2007).
[3] Motoyama, Y. and Hayakawa, K. et al., J. Health Sci., 55, 845 (2009).
[4] Hayakawa, K.(ed), Polycyclic Aromatic Hydrocarbons Environmental Behavior and Toxicity in East Asia,. Springer, Feb. 2018.
[5] Hayakawa, K., et al (Eds), Trans-Boundary Pollution in North-East Asia, NOVA Science Publishers, Aug. 2018.
[6] Hayakawa, K. et al., Environ. Pollut., 233, 474 (2018).