Gradients in PM2.5 over India: Five city study

Exceedances and trends of particulate matter (PM2.5) in five Indian megacities

“…The variation in the PM 2.5 levels for a location is an interplay of emissions, geography, and meteorological conditions ( Alimissis et al, 2018 ; Ganguly et al, 2019 ; Nair et al, 2007 ). Previously, the diurnal and seasonal variations have been reported for five cities for the period of fewer than four years 2013–2016 by Sreekanth et al (2018) and for four cities excluding Kolkata for four years (2015–2018) by Chen et al (2020) . However, these studies did not discuss the trend in the PM 2.5 .…”

“…This USEC data has been used for the study of PM 2.5 levels in the urban environment for different purposes viz. ; to study the trend and characteristics of PM 2.5 ( Chen et al, 2020 ; Fontes et al, 2017 ; Sreekanth et al, 2018 ; Liang et al, 2016 ; Batterman et al, 2016 ; San Martini et al, 2015 ), to compare with other data and model evaluation ( Jiang et al, 2015 ; Li, 2020 ; Matthias et al, 2017 ; Mukherjee and Toohey, 2016 ; Shimadera et al, 2016 ; Uno et al, 2014 ; Wang et al, 2018 ), and to estimate the health impacts ( Han et al, 2020 ; Lowsen and Conway, 2016 ; Luong et al, 2020 ; Nhung et al, 2020 ; Tian et al, 2020 ; Wang et al, 2020 ; You et al, 2016 ; Zhang et al, 2020 ). While most of the studies are carried out in China, few studies have been carried out for other countries including Vietnam ( Hien et al, 2019 ; Luong et al, 2020 ), Japan ( Shimadera et al, 2016 ) Indonesia ( Kusuma et al, 2019 ), Mongolia ( Hill et al, 2017 ), Bangladesh ( Auvee and Bashar, 2019 ), and Singapore ( Liu and Salvo, 2018 ).…”

“…USEC AQ data for India has been mostly utilized for PM 2.5 variability and trend analysis ( Bhardwaj and Pruthi, 2019 ; Chen et al, 2020 ; Dhammapala, 2019 ; Pommier et al, 2018 ; Sreekanth et al, 2018 ; Yang et al, 2018 ). Also, the data has been utilized for comparison with the PM 2.5 data collected by Central Pollution Control Board (CPCB) in New Delhi ( Bhardwaj and Pruthi, 2019 ), for utilization as ambient values for indoor air quality study in Mumbai ( Lueker et al, 2020 ), and verification of simulated results ( Mahesh et al, 2019 ; Sreekanth et al, 2017 ).…”

“…Also, the data has been utilized for comparison with the PM 2.5 data collected by Central Pollution Control Board (CPCB) in New Delhi ( Bhardwaj and Pruthi, 2019 ), for utilization as ambient values for indoor air quality study in Mumbai ( Lueker et al, 2020 ), and verification of simulated results ( Mahesh et al, 2019 ; Sreekanth et al, 2017 ). Analysis of hourly PM 2.5 carried out for nearly four years by two different studies at all Indian USEC sites from Jan-2013 to Oct-2016 ( Sreekanth et al, 2018 ) and four sites excluding Kolkata from Mar-2015 to Dec-2018 ( Chen et al, 2020 ) shows Delhi being the most polluted city. Both the studies report winter to be the most polluted season for all the cities because of increased household emissions ( Chowdhury et al, 2019 ; Guttikunda and Calori, 2013 ) and lower boundary layer ( Sathyanadh et al, 2017 ).…”

Impact of COVID-19 lockdown on ambient air quality in megacities of India and implication for air pollution control strategies

“…In Hyderabad, vehicular exhaust (31%) and resuspension of dust (26%) are also major contributors to ambient PM 2.5 levels, followed by combustion (9%), industries (7%), and waste burning (6%) (Gummeneni et al 2011). Furthermore, in India, during summer seasons, planetary boundary layer height increases, and wind speeds help in reducing the PM 2.5 levels (Sreekanth et al 2018).…”