Trends of sulfur and nitrogen deposition from 2003 to 2017 in Japanese remote areas

Sakurako Yamaga; Satomi Ban; Mao Xu; Tatsuya Sakurai; Syuichi Itahashi; Kazuhide Matsuda

doi:10.1016/j.envpol.2021.117842

Trends of sulfur and nitrogen deposition from 2003 to 2017 in Japanese remote areas

Environ Pollut. 2021 Nov 15:289:117842. doi: 10.1016/j.envpol.2021.117842. Epub 2021 Jul 27.

Authors

Sakurako Yamaga¹, Satomi Ban², Mao Xu³, Tatsuya Sakurai⁴, Syuichi Itahashi⁵, Kazuhide Matsuda⁶

Affiliations

¹ Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo, 183-8509, Japan.
² Japan Environmental Sanitation Center, 10-6 Yotsuyakami-cho, Kawasaki, 210-0828, Japan.
³ United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo, 183-8509, Japan.
⁴ School of Science and Engineering, Meisei University, 2-1-1 Hodokubo, Hino, Tokyo, 191-8506, Japan.
⁵ Central Research Institute of Electric Power Industry, 1646 Abiko, Chiba, 270-1194, Japan.
⁶ Graduate School of Agriculture, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo, 183-8509, Japan; United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo, 183-8509, Japan. Electronic address: kmatsuda@cc.tuat.ac.jp.

PMID: 34352635
DOI: 10.1016/j.envpol.2021.117842

Abstract

Emissions of sulfur (S) and nitrogen (N) compounds in East Asia has drastically changed over the last two decades. To assess the influence of the drastic changes in air pollution on ecosystems in Japan, we investigated the trends of S and N deposition during 2003-2017 at remote sites of Acid Deposition Monitoring Network in East Asia (EANET). We measured wet deposition and inferentially estimated dry deposition of S and N using monitoring data from 2003 to 2017 at eight sites. We estimated dry deposition using the inferential method with an updated parameterization for gaseous surface resistance. The linear regression method and nonparametric Mann-Kendall test was used to analyze the temporal trends based on the monthly data sets. High S and N deposition amounts over 10 kg ha^-1 year^-1 were frequently found at most sites. There were significant increase trends in N deposition to S deposition (N/S) ratio at all sites throughout the 15-year period. Some trends were significantly found when the 15-year period was divided into three: 2003-2007, 2008-2012, and 2013-2017. S deposition had significantly decreased over a wide area in Japan, especially at Sado-seki, Happo, Oki, Hedo, and Ogasawara, in 2013-2017. Significant decreases in oxidized N deposition at Sado-seki and Oki were also found in 2013-2017. Because of almost flat N deposition mainly contributed by reduced N deposition, the N/S ratio clearly increased. These trends were associated with the recent reductions in SO₂ and NO_x emissions in China. The NO_x emission reduction of China has not caught up with that of SO₂, and NH₃ emissions have not been reduced. This caused the significant increases in the N/S ratio not only in 2013-2017 but also in 2003-2017.

Keywords: Ammonia; Dry deposition; East asia; Oxidized nitrogen; Reduced nitrogen.

MeSH terms

Air Pollutants* / analysis
Ecosystem
Environmental Monitoring
Japan
Nitrogen* / analysis
Sulfur / analysis

Substances

Air Pollutants
Sulfur
Nitrogen