Naqvi Hasan Raja, Mutreja Guneet, Shakeel Adnan, Siddiqui Masood Ahsan
Department of Geography, Faculty of Natural Sciences, Jamia Millia Islamia, New Delhi, India.
Environmental Systems Research Institute, R & D Center, New Delhi, India.
Remote Sens Appl. 2021 Apr;22:100473. doi: 10.1016/j.rsase.2021.100473. Epub 2021 Jan 30.
The COVID-19 pandemic spread worldwide, such as wind, with more than 400,000 documented cases as of March 24, 2020. In this regard, strict lockdown measures were imposed in India on the same date to stop virus spread. Thereafter, various lockdown impacts were observed, and one of the immediate effects was a reduction in air pollution levels across the world and in India as well. In this study, we have observed approximately 40% reduction in air quality index (AQI) during one month of lockdown in India. The detailed investigations were performed for 14 major hotspot places where the COVID-19 cases were >1000 (as of 1 June 2020) and represents more than 70% associated mortality in India. We assessed the impact of lockdown on different air quality indicators, including ground (PM, PM, NO, SO, O, and AQI) and tropospheric nitric oxide (NO) pollutants, through ground monitoring stations and Sentinel-5 satellite datasets respectively. The highest reductions were noticed in NO (-48.68%), PM (-34.84%) and PM (-33.89%) air pollutant (unit in μg/m) post-lockdown. Moreover, tropospheric NO (mol/m) concentrations were also improved over Delhi, Mumbai, Kolkata, Thane, and Ahmedabad metro cities. We found strong positive correlation of COVID-19 mortality with PM (R = 0.145; r = 0.38) and AQI (R = 0.17; r = 0.412) pollutant indicators that significantly improved next time point. The correlation finding suggests that long-term bad air quality may aggravate the clinical symptoms of the disease.
2019年冠状病毒病（COVID-19）大流行如疾风般在全球蔓延，截至2020年3月24日，有记录的病例超过40万例。鉴于此，印度于同日实施了严格的封锁措施以阻止病毒传播。此后，观察到了各种封锁影响，其中一个直接影响是全球和印度的空气污染水平均有所降低。在本研究中，我们观察到印度在封锁一个月期间空气质量指数（AQI）下降了约40%。对14个主要热点地区进行了详细调查，这些地区的COVID-19病例数>1000（截至2020年6月1日），占印度相关死亡率的70%以上。我们分别通过地面监测站和哨兵-5卫星数据集评估了封锁对不同空气质量指标的影响，包括地面（PM、PM、NO、SO、O和AQI）和对流层一氧化氮（NO）污染物。封锁后，NO（-48.68%）、PM（-34.84%）和PM（-33.89%）空气污染物（单位：μg/m）的降幅最大。此外，德里、孟买、加尔各答、thane和艾哈迈达巴德等大城市的对流层NO（mol/m）浓度也有所改善。我们发现COVID-19死亡率与PM（R = 0.145；r = 0.38）和AQI（R = 0.17；r = 0.412）污染物指标呈强正相关，在下一个时间点显著改善。相关性研究结果表明，长期的恶劣空气质量可能会加重该疾病的临床症状。
