A Correlation based study using air quality and meteorological parameters for the outbreak of COVID-19 on major affected districts in India

Air quality is an important factor for human health conditions. Simultaneously, suitable meteorology poses the circumstances for virus transmission. Hence, we investigated both these two important aspects for the COVID-19 pandemic. We correlated the remote sensing based observations of meteorological parameters and air quality parameters with COVID-19 cases from 657 districts all over the country and found that air quality parameters are playing very crucial role along with a few meteorological parameters for this outbreak. We observed that air temperature, and wind speed were signicantly and positively correlated with COVID-19 cases but precipitation and humidity were negatively correlated with conrmed cases. Cloudiness had no signicant relation in this aspect. Among the air pollutants, O 3 was better correlating with COVID-19 cases. AOD representing the particulate matter concentration also signicantly correlated with such cases majorly over Indo-Gangetic plain region. The carbon-pollutants CO was also very high over the same region. Though NO 2 and SO 2 were reduced during lockdown, due to the power generation and mining activities both these gases were quite highly correlated over eastern India region. We noted the eastern and western coastal districts of India and districts from the low-lying plain areas had more cases during this pandemic. Our study suggests that improving air quality with proper strict regulations and complete lockdown during the peak of pandemic could reduce the misfortune in all over India. Hence, the summer season could be susceptible and might pose a gesture of seasonality for this disease.


Introduction
In the 21st century, the world has been battle-scarred by the pernicious ordeal of coronavirus disease Since a handful of studies had reckoned that the inferior air quality had e caciously swayed to aggravate the COVID-19 emanation, hence it becomes also requisite to Loading [MathJax]/jax/output/CommonHTML/fonts/TeX/fontdata.js investigate whether the convivial air quality has been benevolent to convalesce the COVID-19 patients in India. Therefore, the present study has been rmed to analyse the association of COVID-19 incidences (i.e. transmission) and recovery cases with weather and air quality parameters across the country, as well as proffered a comparative assessment for estimating con rm and recovery cases availing the non-linear complex relationship.

Data and Methodology
Counts of Con rmed and Recovered cases for all the available districts in India have been acquired from https://www.covid19india.org/ for the period of April, 2020 to May, 2021. Spatial data for different meteorological parameters -Air Temperature, Bias-corrected Total Precipitation, Humidity, Cloud Cover, processed in ArcGIS software, adjoined and related with the monthly cumulative counts of con rmed and recovery cases for each months for each of those selected districts.

Infections and recoveries during 1st COVID-19 waves in India
The district wise spatial distribution of COVID-19 con rmed cases and recoveries during the 1st COVID-19 wave (up to March, 2021) are shown in Fig. 1. It shows that 34.8% districts had noted cases within the range of 10,000 to 1,00,000; while only 3% districts in India registered more than 1 lakh cases during this study period. Noteworthy, most of the districts have registered counts of infective cases within the range of 2500-5000 following the range of 10000-25000. The spatial distribution of cases also depict that the coastal districts were more anguished by misfortune than the districts located in the interior part of the country whereas the districts from the Himalayan Mountains and its foothills had lesser strife during this pandemic. The peak of pandemic was during the early September, 2020 when the daily death counts and con rmed cases were highest, however daily test positivity was highest during July. These trends were at their trough during the winter followed by the post-monsoon seasons but again started to incline since March, 2021.

Pearson's correlation test
Pearson's correlation technique was applied to explore the degree of association of environmental parameters with infected and recovered cases. A correlogram is also being prepared to better represent the interrelation of the variables.  In the current study we found all the seven air quality parameters to be signi cantly and positively correlated with con rmed cases. Figure 2 depicts that monthly con rmed cases was better correlated with monthly average concentration of O 3 (0.588) followed by AOD ( fuel combustion and COVID-19 outbreak patterns. Till date, a minimal study has obtained SO 2 and BC to investigate the surging of COVID-19. It was quite distinctive that higher SO 2 and coronavirus outbreak were experienced over IGP, Odisha, coastal areas of Gujarat and Maharashtra. Therefore, it can be quite distinctive that the ensued elevated pollution due to outrageous fossil fuel consumption could cause the neighbourhood to be less immune and predisposed to severe respiratory infection like COVID-19 ( . Even though we found that the IGP followed by the coastal districts of West Bengal, Odisha, Andhra Pradesh, Maharashtra, Kerala, Tamilnadu had inhaled quite bad air where each states had registered more than 30,000 cases during that period. Therefore, it suggests that the shoddy air quality could not be discretely blameworthy for coronavirus dissemination in India, rather bad air with successively increasing AT in summer environment could be held responsible.

Conclusion
Our conscientious study suggests that the summer tropical environment in India may spare a more a rmative condition for SARS-CoV-2 transmission. Instead of squashing the COVID-19 curve, higher air temperature may signi cantly assist an augment in pandemic predicament in India. Comparatively higher wind in drier areas could indulge the virus to unfurl more. Besides, the negative correlation between precipitation and infections. The positive correlation between coal blazed pollution and COVID-19 outbreak, as well as the negative association between the recovery count from this disease and prevailing regional pollution levels stoutly suggest that the exorbitant air pollution due to bounteous non-renewable energy generation and its perpetual consumption might perturb the inbred immunity of residents in circumjacent area, and hinder them also in agile recovery from this disease. The concurrent heath tribulation and the interconnection of diseases affecting multiple organs are also decisively discerned during COVID-19 infections. During or in a later stage of treatment, several patients are also condemned to various post-syndrome infections mostly related to cardiovascular and respiratory disorders which might be the rami cations of virulent vulnerability to the gaseous pollution. Hence it altogether asserts Loading [MathJax]/jax/output/CommonHTML/fonts/TeX/fontdata.js that the environment needs to be ameliorated immensely by its standards to alleviate such deadly pandemic. The pre-eminence of weather parameters on air quality is indubitable and evinced globally and its signi cant association with COVID-19 dissemination during a year-long period over India has been certainly revealed through the present study.   Correlogram for the present analysis Loading [MathJax]/jax/output/CommonHTML/fonts/TeX/fontdata.js