Effect of COVID-19-induced lockdown on NO2 pollution using TROPOMI and ground-based CPCB observations in Delhi NCR, India.

The present study investigates the reduction in nitrogen dioxide (NO2) levels using satellite-based (Sentinel-5P TROPOMI) and ground-based (Central Pollution Control Board) observations of 2020. The lockdown duration, monthly, seasonal and annual changes in NO2 were assessed comparing the similar time period in 2019. The study also examines the role of atmospheric parameters like wind speed, air temperature, relative humidity, solar radiation and atmospheric pressure in altering the monthly and annual values of the pollutant. It was ascertained that there was a mean reduction of ~ 61% (~ 66.5%), ~ 58% (~ 51%) in daily mean NO2 pollution during lockdown phase 1 when compared with similar period of 2019 and pre-lockdown phase in 2020 from ground-based (satellite-based) measurements. April month with ~ 57% (~ 57%), summer season with ~ 48% (~ 32%) decline and an annual reduction of ~ 20% (~ 18%) in tropospheric NO2 values were observed (p < 0.001) compared to similar time periods of 2019. It was assessed that the meteorological parameters remained almost similar during various parts of the year in 2019 and 2020, indicating a negligent role in reducing the values of atmospheric pollution, particularly NO2 in the study area. It was concluded that the halt in anthropogenic activities and associated factors was mainly responsible for the reduced values in the Delhi conglomerate. Similar work can be proposed for other pollutants to holistically describe the pollution scenario as an aftermath of COVID-19-induced lockdown.

Air Quality Decrement after Lockdown in Major Cities of Rajasthan, India

The lockdown restrictions during the COVID-19 pandemic provided a 'path' of reinstatement of the air quality globally. Despite several financial challenges, air quality improvement positively impacted the environment due to lockdown in the worst pandemic situations. The present study assessed the air pollution scenario in the post lockdown phase in the seven major metropolises of Rajasthan, namely, Jodhpur, Alwar, Jaipur, Kota, Pali, Ajmer, and Udaipur) in the recent pandemic year 2020. The air pollution scenario is determined with the help of the Air Quality Index (AQI) and the concentration level of PM2.5 PM10, NO2, and SO2. This study reveals that Most Cities of Rajasthan are violating India's national ambient air quality standards (NAAQS). It is found that Jodhpur is on rank first in terms of pollution levels, followed by Alwar, Jaipur, Pali, and Udaipur. The pollution level was higher before the lockdown period then reduced to a certain level due to restricted activities in lockdown. The pollution level is not rapidly increased after lockdown due to rainfall occurred in Rainy season from Southwest monsoon. Winter Season consists of higher concentration levels of pollutant and higher than Before Lockdown Period. The study shows the Significant impact of lockdown in reducing air pollution levels in cities. But imposing lockdown in a city or country is not a permanent solution to curb air pollution. So, regulating agencies and stakeholders should implement better control and reduction technologies for Indian cities. © The Electrochemical Society

Revealing the Declining Trend of NO2and SO2Concentration in Indian Cities during Pandemic Lockdown

The highly polluted Indian cities are retained their normal state during COVID-19 pandemic lockdown. Thus, the study aims to analysis the lockdown impact on NO2 and SO2 in the selected cities. So, the lockdown relative changes (C) are calculated based on baseline and pre-lockdown, for which the ground (Central Pollution Control Board data) and satellite (Sentinel 5P data) measured NO2 and SO2 data were utilised. The study reveals that the average pollutants concentration of NO2 and SO2 is declined to below-average level and indicates that the average dropdown level of NO2 and SO2 are -45.4% and -30.2% for ground pollutants;-45.1% and -43.4% for satellite pollutants respectively. The pandemic lockdown has restricted industrial, vehicular emission, and other anthropogenic activities which resulted in a positive effect on air quality. © 2021 IEEE.

Assessment of Particulate Matters Especially PM2.5 and PM10 Concentration During and Before Lockdown in the Various Metropolitan Cities of India

This study was carried out to evaluate the concentration of particulate matter i.e. PM2.5 & PM10 in the selected metropolitan area (Mumbai, Delhi, Kolkata & Bengaluru). Data used and analysed in this research was taken from the official website of CPCB (Central Pollution Control Board). Analysis is done before and during the lockdown period. For the current analysis, data from the chosen parameters (Particulate Matter with a diameter equal to or less than 10 microns (PM10) and particulate matter with a diameter equal or less than 2.5 microns (PM2.5) are gathered and analysed from the source i.e. CPCP. Site wise, histogram analysis was also performed. The PM concentration is found to be the highest in Delhi, among all locations. During the study period, a clear association between PM10 and PM2.5 was observed at all the sites. A great change was observed in the values of Particulate Matter before and after the lockout cycles. In metro cities, values higher than PM10 were found to be PM2.5, except for Bangalore, where values lower than PM10 were found to be PM2.5. During the lockdown, Bengaluru was least polluted while Delhi was the most polluted city among all these metropolitan cities. During the analysis it was observed that the level of Particulate Matter (PM) got reduced as all kind of anthropogenic activities were stopped. Vehicular activities and other construction work were also stopped so it helped to reduce the PM from the surroundings. COVID-19 brought a meaningful drive to combat all kind of air related pollution and it is observed during this research. © 2022 by ASERS® Publishing. All rights reserved.

Current perspectives of biomedical waste management in context of COVID-19".

COVID-19 pandemic and it's consequent biomedical waste is an unprecedented challenge worldwide. Biomedical waste generated during COVID-19 patient isolation, testing and care needs special consideration as it challenges the previous notion that only 15-20% of waste can be considered infectious. With establishment of new home quarantine facility, isolation/quarantine centres the chances of general waste getting contaminated with biomedical waste has increased exponentially. Through this systematic review the authors searched for all possible queries raised by different researchers on COVID19 waste management on Pubmed. A summary of all the different issues unique to COVID19 waste was prepared. Guidelines, rules and recommendation given by national and international agencies published till date were taken into account while trying to answer all the above questions raised by different studies. The key step in COVID19 waste management is segregation of biomedical waste from solid waste. Waste generated from COVID19 patients is like any other infectious waste, therefore creating public awareness about the COVID19 waste hazards and segregation at source is highlighted in all guidelines as a recommendation. These guidelines for management of waste generated during diagnostics and treatment of COVID-19 suspected or confirmed patients, are required to be followed in addition to existing practices under regulation. BMWM in COVID-19 context is a public health concern and is both a legal and social responsibility for all stakeholders.

COVID-19's lockdown effect on air quality in Indian cities using air quality zonal modeling.

The complete lockdown due to COVID-19 pandemic has contributed to the improvement of air quality across the countries particularly in developing countries including India. This study aims to assess the air quality by monitoring major atmospheric pollutants such as AOD, CO, PM2.5, NO2, O3 and SO2 in 15 major cities of India using Air Quality Zonal Modeling. The study is based on two different data sources; (a) grid data (MODIS- Terra, MERRA-2, OMI and AIRS, Global Modeling and Assimilation Office, NASA) and (b) ground monitoring station data provided by Central Pollution Control Board (CPCB) / State Pollution Control Board (SPCB). The remotely sensed data demonstrated that the concentration of PM2.5 has declined by 14%, about 30% of NO2 in million-plus cities, 2.06% CO, SO2 within the range of 5 to 60%, whereas the concentration of O3 has increased by 1 to 3% in majority of cities compared with pre lockdown. On the other hand, CPCB/SPCB data showed more than 40% decrease in PM2.5 and 47% decrease in PM10 in north Indian cities, more than 35% decrease in NO2 in metropolitan cities, more than 85% decrease in SO2 in Chennai and Nagpur and more than 17% increase in O3 in five cities amid 43 days pandemic lockdown. The restrictions of anthropogenic activities have substantial effect on the emission of primary atmospheric pollutants.

Temporary reduction in air pollution due to anthropogenic activity switch-off during COVID-19 lockdown in northern parts of India.

Due to fast and deadly spread of corona virus (COVID-19), the Government of India implemented lockdown in the entire country from 25 April 2020. So, we studied the differences in the air quality index (AQI) of Delhi (DTU, Okhla and Patparganj), Haryana (Jind, Palwal and Hisar) and Uttar Pradesh (Agra, Kanpur and Greater Noida) from 17 February 2020 to 4 May 2020. The AQI was calculated by combination of individual sub-indices of seven pollutants, namely PM2.5, PM10, NO2, NH3, SO2, CO and O3, collected from the Central Pollution Control Board website. The AQI has improved by up to 30-46.67% after lockdown. The AQI slope values - 1.87, - 1.70 and - 1.35 were reported for Delhi, - 1.11, - 1.31 and - 1.04 were observed for Haryana and - 1.48, - 1.79 and - 1.78 were found for Uttar Pradesh (UP), which may be attributed to limited access of transportation and industrial facilities due to lockdown. The ozone (O3) concentration was high at Delhi because of lesser greenery as compared to UP and Haryana, which provides higher atmospheric temperature favourable for O3 formation. The air mass back trajectory (AMBT) analysis reveals the contribution of air mass from Europe, Africa and Gulf countries as well as local emissions from Indo-Gangetic Plain, Madhya Pradesh and Maharashtra states of India.

SARS-CoV-2 pandemic lockdown: Effects on air quality in the industrialized Gujarat state of India.

Two weeks after the world health organization described the novel coronavirus (SARS-CoV-2) outbreak as pandemic, the Indian government implemented lockdown of industrial activities and traffic flows across the entire nation between March 24 and May 31, 2020. In this paper, we estimated the improvements achieved in air quality during the lockdown period (March 24, 2020 and April 20, 2020) compared to the pre-lockdown (January 1, 2020 and March 23, 2020) by analyzing PM2.5, PM10, SO2, CO, NO2 and O3 data from nine different air quality monitoring stations distributed across four different zones of the industrialized Gujarat state of western Indian. The Central Pollution Control Board (CPCB)-Air Quality Index (AQI) illustrated better air qualities during the lockdown with higher improvements in the zones 2 (Ahmedabad and Gandhinagar) and 3 (Jamnagar and Rajkot), and moderate improvements in the zones 1 (Surat, Ankleshwar and Vadodra) and 4 (Bhuj and Palanpur). The concentrations of PM2.5, PM10, and NO2 were reduced by 38-78%, 32-80% and 30-84%, respectively. Functioning of the power plants possibly led to less reduction in CO (3-55%) and the declined emission of NO helped to improve O3 (16-48%) contents. We observed an overall improvement of 58% in AQI for the first four months of 2020 compared to the same interval of previous year. This positive outcome resulted from the lockdown restrictions might help to modify the existing environmental policies of the region.