The declaration of COVID-19 pandemic by the WHO initiated a series of lockdowns globally that varied in stringency and duration; however, the spatiotemporal effects of these lockdowns on air quality remain understudied. This study evaluates the global impact of lockdowns on air pollutants using tropospheric and ground-level indicators over a five-month period. Moreover, the relationship between air pollution and COVID-19 cases and mortalities was examined. Changes in the global tropospheric (NO₂, aerosols, and O₃) and ground-level (PM_2.5, PM₁₀, NO₂, and O₃) pollutants were observed, and the maximum air quality improvement was observed immediately after lockdown. Except for a few countries, a decline in air pollutants correlated with a reduction in Land Surface Temperature (LST). Notably, regions with higher tropospheric NO₂ and aerosol concentrations were also COVID-19 hotspots. Our analysis showed moderate positive correlation for NO₂ with COVID-19 cases (R² = 0.33; r = 0.57, P = 0.006) and mortalities (R² = 0.40; r = 0.63, P = 0.015), while O₃ showed a weak-moderate positive correlation with COVID-19 cases (R² = 0.22; r = 0.47, P = 0.003) and mortalities (R² = 0.12; r = 0.35, P = 0.012). However, PM_2.5, and PM₁₀ showed no significant correlation with either COVID-19 cases or mortality. This study reveals that humans living under adverse air pollution conditions are at higher risk of COVID-19 infection and mortality.

世界卫生组织宣布 COVID-19 大流行，在全球范围内启动了一系列封锁措施，其严格程度和持续时间各不相同；然而，这些封锁对空气质量的时空影响仍未得到充分研究。这项研究利用五个月内的对流层和地面指标评估了封锁对空气污染物的全球影响。此外，还研究了空气污染与 COVID-19 病例和死亡率之间的关系。观察到全球对流层（NO ₂ 、气溶胶和O ₃ ）和地面（PM _2.5 、PM ₁₀ 、NO ₂和O ₃ ）污染物的变化，并且在封锁后立即观察到最大程度的空气质量改善。除少数国家外，空气污染物的减少与地表温度（LST）的降低相关。值得注意的是，对流层 NO ₂和气溶胶浓度较高的地区也是 COVID-19 的热点地区。我们的分析显示，NO ₂与 COVID-19 病例（R ² = 0.33；r = 0.57， P = 0.006）和死亡率（R ² = 0.40；r = 0.63， P = 0.015）呈中度正相关，而 O ₃显示与 COVID-19 病例（R ² = 0.22；r = 0.47， P = 0.003）和死亡率（R ² = 0.12；r = 0.35， P = 0.012）呈弱-中度正相关。然而，PM _2.5和 PM ₁₀与 COVID-19 病例或死亡率没有显着相关性。这项研究表明，生活在不良空气污染条件下的人类感染 COVID-19 和死亡的风险更高。