[H-CG26] 農業残渣焼却のもたらす大気汚染と健康影響および解決への道筋

[HCG26-05] Unravelling the link between air pollution in Delhi and Rice Crop Residue Burning in Punjab and Haryana during 2022 and 2023 field campaign

*Poonam Mangaraj¹、Yutaka Matsumi²、Akash Biswal¹、Kazuyo Yamaji³、Masayuki Takigawa⁴、Hikaru Araki¹、Natsuko Yasutomi¹、Tomoki Nakayama⁵、Prabir K Patra^1,4、Sachiko Hayashida¹、Akansha Sharma⁶、A P Dimri⁶、Surendra K Dhaka⁷、Manpreet S Bhatti⁸、Mizuo Kajino⁹、Sanjeev Bhardwaj¹⁰、Ravindra Khaiwal¹⁰、Suman Mor¹¹、Ravi K Kunchala¹²、Vimal J Vazhathara¹²、Tuhin K Mandal¹³、Prakhar Mishra¹⁴、Tanbir Singh¹⁵、Kamal Vatta¹⁶ (1.Research Institute for Humanity and Nature, Kyoto 6038047, Japan 、2.Institute for Space-Earth Environmental Research, Nagoya University, Nagoya 4648601, Japan、3.Graduate School of Maritime Sciences, Kobe University, Kobe 6580022, Japan 、4.Research Institute for Global Change, JAMSTEC, Yokohama 2360001, Japan 、5.Faculty of Environmental Science, Nagasaki University, Nagasaki 8528521, Japan 、6.School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110067, India、7.Radio and Atmospheric Physics Lab, Rajdhani College, University of Delhi, New Delhi, India、8.Department of Botanical and Environmental Sciences, Guru Nanak Dev University, Amritsar, Punjab 143005, India 、9.Meteorological Research Institute, Japan Meteorological Agency, Ibaraki 3050052, Japan、10.Department of Community Medicine and School of Public Health, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh 160012, India、11.Department of Environment Studies, Panjab University, Chandigarh 160014, India 、12.Center for Atmospheric Science, Indian Institute of Technology (IIT)-Delhi, New Delhi 110016, India 、13.Environmental Sciences & Biomedical Metrology Division, CSIR-National Physical Laboratory, New Delhi, India、14.Department of Civil Engineering, Indian Institute of Technology (IIT)-Roorkee, Uttarakhand 247667, India、15.SCVB Government College, Palampur, Himachal Pradesh, India、16.Department of Economics and Sociology, Punjab Agricultural University, Ludhiana, Punjab 141004, India)

キーワード：Crop Residue Burning, Kharif Rice, PM2.5, Northwest India, Environmental Issue

Crop residue burning (CRB) is a major environmental issue that frequently makes headlines during harvest season owing to severe air pollution. The harvesting season for kharif rice (October to November) in northwest India coincides with the shift in weather patterns. The CRB, particularly those associated with kharif rice paddy in Punjab and Haryana, is believed to play a significant role in worsening air pollution in the Delhi national capital region (NCR). Due to a lack of simultaneous high-density network observations including the both source and receptor regions, the association between growing particulate matter of PM2.5 in Delhi-NCR and CRB in Punjab and Haryana is debated and hinders effective policymaking to mitigate air pollution in the Delhi-NCR. We established a network of 30 Compact & Useful PM_2.5 Instrument with Gas sensors (CUPI-Gs) during extensive field campaigns covering Punjab, Haryana, and Delhi-NCR from September to November of 2022 and 2023. The continuous observations conducted in 2022–2023, recorded a considerable drop in fire detection counts (FDCs) of 31-37% in Punjab and Haryana regions. In contrast, a rise in PM_2.5 levels of around 20% was observed over the Delhi-NCR region. Variabilities in concentrations of PM_2.5 and carbon monoxide (CO) in the Delhi-NCR were also found to be independent of those in Punjab and Haryana. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) for 24-hour-backward at three different heights indicated a distinct PM_2.5 plume over Delhi-NCR, likely due to the prevalence of low-wind conditions (<1 m s^-1) in 2023 as compared to the year 2022 (>2 m s^-1). Based on sensitivity simulations of the Community Multiscale Air Quality Modeling System (CMAQ), we detected a rise in PM_2.5 at surface locations in Punjab and Haryana for eight times high CRB emissions, but no significant change in PM_2.5 levels in Delhi-NCR. In this study, we decipher the links and persistency between ground conditions (fire counts, meteorology, etc.) and PM_2.5 abundances. Some of this information is provided through our website in near real-time: https://aakash-rihn.org/en/campaign2023/.