The COVID-19 global pandemic has necessitated some drastic measures to curb its spread. Several countries around the world instituted partial or total lockdown as part of the control measures for the pandemic. This presented a unique opportunity to study air pollution under reduced human activities. In this study, we investigated the impact of the lockdown on air pollution in three highly populated and industrious cities in Nigeria. Compared with historical mean values, NO2 levels increased marginally by 0.3% and 12% in Lagos and Kaduna respectively. However, the city of Port Harcourt saw a decrease of 1.1% and 215.5% in NO2 and SO2 levels respectively. Elevated levels of O3 were observed during the period of lockdown. Our result suggests that there are other sources of air pollution apart from transportation and industrial sources. Our findings showed that the COVID-19-induced lockdown was responsible for a decrease in NO2 levels in two of the locations studied. These results presents an opportunity for country wide policies to mitigate the impact of air pollution on the health of citizens.

中文翻译：

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COVID -19 大流行封锁对尼日利亚选定城市无机污染物分布的影响

COVID-19 全球大流行需要采取一些严厉措施来遏制其传播。作为大流行控制措施的一部分，世界上几个国家实施了部分或全部封锁。这为研究人类活动减少下的空气污染提供了独特的机会。在这项研究中，我们调查了封锁对尼日利亚三个人口稠密和工业城市的空气污染的影响。与历史平均值相比，拉各斯和卡杜纳的二氧化氮水平分别微升 0.3% 和 12%。然而，哈科特港市的二氧化氮和二氧化硫水平分别下降了 1.1% 和 215.5%。在封锁期间观察到 O3 水平升高。我们的结果表明，除了交通和工业来源之外，还有其他空气污染来源。我们的研究结果表明，COVID-19 引起的封锁是导致所研究的两个地点的二氧化氮水平下降的原因。这些结果为国家政策提供了一个机会，以减轻空气污染对公民健康的影响。