Department of Geography, Faculty of Natural Sciences, Jamia Millia Islamia, New Delhi, India.
Department of Biochemistry, Amity University, Jaipur, Rajasthan, India.
Environ Pollut. 2021 Jan 1;268(Pt A):115691. doi: 10.1016/j.envpol.2020.115691. Epub 2020 Oct 27.
India enforced stringent lockdown measures on March 24, 2020 to mitigate the spread of the Severe Acute Respiratory Syndrome Coronovirus-2 (SARS-CoV-2). Here, we examined the impact of lockdown on the air quality index (AQI) [including ambient particulate matter (PM and PM), nitrogen dioxide (NO), sulfur dioxide (SO), carbon monoxide (CO), ozone (O), and ammonia (NH)] and tropospheric NO and O densities through Sentinel-5 satellite data approximately 1 d post-lockdown and one month pre-lockdown and post-lockdown. Our findings revealed a marked reduction in the ambient AQI (estimated mean reduction of 17.75% and 20.70%, respectively), tropospheric NO density, and land surface temperature (LST) during post-lockdown compared with the pre-lockdown period or corresponding months in 2019, except for a few sites with substantial coal mining and active power plants. We observed a modest increase in the O density post-lockdown, thereby indicating improved tropospheric air quality. As a favorable outcome of the COVID-19 lockdown, road accident-related mortalities declined by 72-folds. Cities with poor air quality correlate with higher COVID-19 cases and deaths (r = 0.504 and r = 0.590 for NO; r = 0.744 and r = 0.435 for AQI). Conversely, low mortality was reported in cities with better air quality. These results show a correlation between the COVID-19 vulnerable regions and AQI hotspots, thereby suggesting that air pollution may exacerbate clinical manifestations of the disease. However, a prolonged lockdown may nullify the beneficial environmental outcomes by adversely affecting socioeconomic and health aspects.
2020 年 3 月 24 日，印度实施了严格的封锁措施，以减缓严重急性呼吸系统综合征冠状病毒 2（SARS-CoV-2）的传播。在这里，我们通过 Sentinel-5 卫星数据，大约在封锁后 1 天和封锁前 1 个月和封锁后检查了封锁对空气质量指数（AQI）[包括环境颗粒物（PM 和 PM）、二氧化氮（NO）、二氧化硫（SO）、一氧化碳（CO）、臭氧（O）和氨（NH）]和对流层 NO 和 O 密度的影响。我们的研究结果表明，与封锁前时期或 2019 年同期相比，封锁后环境 AQI（分别估计平均减少 17.75%和 20.70%）、对流层 NO 密度和地表温度（LST）显著降低，除了少数有大量煤矿和活跃的发电厂的地点。我们观察到封锁后 O 密度略有增加，从而表明对流层空气质量有所改善。作为 COVID-19 封锁的有利结果，与道路事故相关的死亡率下降了 72 倍。空气质量差的城市与更高的 COVID-19 病例和死亡相关（NO 为 r = 0.504 和 r = 0.590；AQI 为 r = 0.744 和 r = 0.435）。相反，空气质量较好的城市报告的死亡率较低。这些结果表明 COVID-19 脆弱地区与 AQI 热点之间存在相关性，表明空气污染可能会加剧疾病的临床表现。然而，长期封锁可能会通过对社会经济和健康方面产生不利影响，从而抵消有利的环境结果。
