How air quality and COVID-19 transmission change under different lockdown scenarios? A case from Dhaka city, Bangladesh

Abstract

The transmission of novel coronavirus (COVID-19) can be reduced by implementing a lockdown policy, which has also been proven as an effective control measure for air pollution in the urban cities. In this study, we applied ground- and satellite-based data of five criteria air pollutants (PM2.5, NO 2 , SO 2 , O 3 , and CO) and meteorological factors from March 8 to May 15, 2020 (before, partial-, and full-lockdown). The generalized additive models (GAMs), wavelet coherence, and random forest (RF) model were employed to explore the relationship between air quality indicators and COVID-19 transmission in Dhaka city. Results show that overall, 26, 20.4, 17.5, 9.7 and 8.8% declined in PM 2.5, NO 2 , SO 2 , O 3 , and CO concentrations, respectively, in Dhaka City during the partial and full lockdown compared to the period before the lockdown. The implementation of lockdown policy for containing COVID-19 transmission played a crucial role in reducing air pollution. The findings of wavelet coherence and partial wavelet coherence demonstrate no standalone coherence, but interestingly, multiple wavelet coherence indicated a strong short-term coherence among air pollutants and meteorological factors with the COVID-19 outbreak. Outcomes of GAMs indicated that an increase of 1-unit in long-term exposure to O 3 and CO (lag1) was associated with a 2.9% (95% CI: -0.3%, -5.6%), and 53.9% (95% CI: 0.2%, -107.9%)] decreased risk of COVID-19 infection rate during the full-lockdown period. Whereas, COVID-19 infection and MT (mean temperature) are modulated by a peak during full-lockdown, which is mostly attributed to contact transmission in Dhaka city. RF model revealed among the parameters being studied, MT, RH (relative humidity), and O 3 were the dominant factors that could be associated with COVID-19 cases during the study period. The outcomes reported here could elucidate the effectiveness of lockdown scenarios for COVID-19 containment and air pollution control in Dhaka city.

Containment measures limit environmental effects on COVID-19 early outbreak dynamics

“…The effect of air pollution on COVID-19 spread during early outbreaks was weaker than the effect of local climate. In the early stages of the global outbreak, we observed more severe outbreaks in regions with poor air quality, as gauged by their higher PM2.5 levels, in line with studies suggesting that poor air quality may enhance local transmission and may increase COVID-19 related mortality, possibly not independently of local meteorological conditions (Azuma et al, 2020; Bianconi et al, 2020; Rahman et al, 2020; Wu et al, 2020b; Yao et al, 2020; Zhang et al, 2020). Air pollution can influence COVID-19 spread through different pathways.…”

“…The role of environmental drivers on COVID-19 spatial patterns and growth rate is controversial (Araújo et al, 2020; Carlson et al, 2020a; Carlson et al, 2020b; National Academies of Sciences Engineering and Medicine, 2020). Some authors suggested that this disease had a reduced impact and spread in warm climates, and in areas with low pollution and experiencing intense UV radiation (Merow and Urban, 2020; Rahman et al, 2020; Runkle et al, 2020; Sajadi et al, 2020; Sobral et al, 2020; Wu et al, 2020b; Wu et al, 2020c; Zhang et al, 2020), while others reported that socio-economic factors and airport connections have a much stronger impact than environmental drivers (Coelho et al, 2020; Jaffe et al, 2020).…”

“…Tamerius et al, 2013; Islam et al, 2020a; Kampf et al, 2020; Runkle et al, 2020; Sajadi et al, 2020; Sobral et al, 2020; Wu et al, 2020c), and air pollution (e.g. Bianconi et al, 2020; Rahman et al, 2020; Wu et al, 2020b; Yao et al, 2020; Zhang et al, 2020), while accounting for major socio-economic features of the affected regions (Coelho et al, 2020; Jaffe et al, 2020; Shammi et al, 2020). However, results of these studies were sometimes controversial, casting doubts on the possibility of correctly identifying environmental signals on COVID-19 spread dynamics (Carlson et al, 2020a; Carlson et al, 2020b).…”

Change of CO Concentration Due to the COVID-19 Lockdown in China Observed by Surface and Satellite Observations

“…The strict measures related to COVID-19 had a large impact on economic activities, including energy production, industrial activities, and transportation [4,5]. As a result, the emissions of many atmospheric components were significantly reduced [6][7][8][9]. There was a 3.7% decrease in Chinese carbon dioxide (CO 2 ) emissions in the first half of 2020 related to the COVID-19 pandemic [10].…”

The role of airborne particles and environmental considerations in the transmission of SARS-CoV-2

“…The lockdown not only decreased the air pollution significantly but also affected through social distancing and isolation of the COVID-19 cases from the unaffected population. A study informed that the lowest rate of COVID-19 confirmed cases were found in full lockdown ( Rahman et al, 2021 ). The COVID-19 lockdown certainly is expected to have a synergistic effect in bringing down transmission of virus.…”