Abstract
The Coronavirus Disease 2019 (COVID-19) broke out in 2019 and spread rapidly to the whole world. Lockdown policies were adopted by Pakistan to control the rapid dispersion of COVID-19. These lockdown measures restricted economic and human activities immensely to lower number of the COVID-19 cases and associated illnesses. Additionally, air pollution and meteorological conditions also play a crucial role in the spread of COVID-19 in Pakistan. Therefore, this study mainly focuses on the changes in concentrations of selected air pollutants (coarse particulate matter (PM10), fine particulate matter (PM2.5), sulphur dioxide (SO2) and Ozone (O3)) along with meteorological parameters (relative humidity, temperature, and wind speed) during March 1 to April 25 from 2018 to 2020. The present study acquired available air pollutants data from Environmental Protection Department, meteorological parameters from the wunderground, vertical profiles and backward trajectories from National Oceanic and Atmospheric Administration (NOAA) portal. Ground-based observations showed a decline in the mean concentrations of PM2.5 and PM10 by 51.3 and 65.7% and an increase in concentrations of O3 and SO2 by 82.6 and 21.1%, respectively in 2020 compared to those measured in the year 2019. During phase 4 (lockdown) of 2020, PM10 and PM2.5 decreased by 88.0 and 82.9% compared to 2019 and 2018, respectively. Moreover, the SO2 concentrations were reduced by 59.1% in phase 3 of 2020 compared to those measured in 2019. In phase 4, O3 concentrations decreased by 29.4% in 2020 compared to 2018 but no reduction was observed in O3 compared to 2019. The findings indicate a decline in concentrations of air pollutants during the lockdown due to the restrictions on human, transportation, commercial and industrial activities. These results would be important for policymakers to develop some air pollutant control action plans to mitigate air pollution problems in Pakistan.
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Data Availability
The datasets can be availed from the corresponding author upon reasonable request.
References
Addas A, Maghrabi A (2021) The Impact of COVID-19 Lockdowns on air quality—a global review. Sustainability 13(18):10212. https://doi.org/10.3390/SU131810212
Ali G, Abbas S, Qamer FM, Wong MS, Rasul G, Irteza SM, Shahzad N (2021) Environmental impacts of shifts in energy, emissions, and urban heat island during the COVID-19 lockdown across Pakistan. J Clean Prod 291:125806. https://doi.org/10.1016/j.jclepro.2021.125806
Ali M, Tariq S, Mahmood K, Daud A, Batool A, ul-Haq Z (2014) A study of aerosol properties over Lahore (Pakistan) by using AERONET data. Asia-Pac J Atmos Sci 50(2):153–162. https://doi.org/10.1007/s13143-014-0004-y
Alshayef MS, Javed A, Mohammed AM, Bin (2019) Delineation of hydrocarbon potential zones in Masila oil field. Yemen Spat Inf Res 27(2):121–135. https://doi.org/10.1007/s41324-018-0220-0
Bera B, Bhattacharjee S, Sengupta N, Saha S (2021) PM2.5 concentration prediction during COVID-19 lockdown over Kolkata metropolitan city, India using MLR and ANN models. Environ Challenges 4(May):100155. https://doi.org/10.1016/j.envc.2021.100155
Bilal M, Mhawish A, Nichol JE, Qiu Z, Nazeer M, Ali MA, de Leeuw G, Levy RC, Wang Y, Chen Y, Wang L, Shi Y, Bleiweiss MP, Mazhar U, Atique L, Ke S (2021) Air pollution scenario over Pakistan: characterization and ranking of extremely polluted cities using long-term concentrations of aerosols and trace gases. Remote Sens Environ 264(June):112617. https://doi.org/10.1016/j.rse.2021.112617
Chauhan A, Singh RP (2020) Decline in PM2.5 concentrations over major cities around the world associated with COVID-19. Environ Res 187:109634. https://doi.org/10.1016/j.envres.2020.109634
Chauhan A, Singh RP (2021) Effect of lockdown on hcho and trace gases over India during March 2020. Aerosol Air Qual Res 21(4):1–19. https://doi.org/10.4209/aaqr.2020.07.0445
Chen S-L, Chang S-W, Chen Y-J, Chen H-L (2021) Possible warming effect of fine particulate matter in the atmosphere. Commun Earth Environ 2(1):1–9. https://doi.org/10.1038/s43247-021-00278-5
Cocker DR, Clegg SL, Flagan RC, Seinfeld JH (2001) The effect of water on gas–particle partitioning of secondary organic aerosol. Part i: α-Pinene/ozone. Syst Atmos Environ 35(35):6049–6072. https://doi.org/10.1016/S1352-2310(01)00404-6
Colbeck I, Sidra S, Ali Z, Ahmed S, Nasir ZA (2019) Spatial and temporal variations in indoor air quality in Lahore, Pakistan. Int J Environ Sci Technol 16(6):2565–2572. https://doi.org/10.1007/s13762-018-1693-z
Dantas G, Siciliano B, França BB, da Silva CM, Arbilla G (2020) The impact of COVID-19 partial lockdown on the air quality of the city of Rio de Janeiro. Brazil Sci Total Environ 729:139085. https://doi.org/10.1016/j.scitotenv.2020.139085
Faust JA, Wong JPS, Lee AKY, Abbatt JPD (2017) Role of aerosol liquid water in secondary organic aerosol formation from volatile organic compounds. Environ Sci Technol 51(3):1405–1413. https://doi.org/10.1021/ACS.EST.6B04700/SUPPL_FILE/ES6B04700_SI_001.PDF
Filonchyk M, Hurynovich V, Yan H, Gusev A, Shpilevskaya N (2020) Impact assessment of COVID-19 on variations of SO2, NO2, CO and AOD over East China. Aerosol Air Qual Res 20(7):1530–1540. https://doi.org/10.4209/aaqr.2020.05.0226
Guevara M, Jorba O, Soret A, Petetin H, Bowdalo D, Serradell K, Tena C, Van Der Gon HD, Kuenen J, Peuch VH, Pérez Garciá-Pando C (2021) Time-resolved emission reductions for atmospheric chemistry modelling in Europe during the COVID-19 lockdowns. Atmos Chem Phys 21(2):773–797. https://doi.org/10.5194/acp-21-773-2021
Hashim BM, Al-Naseri SK, Al-Maliki A, Al-Ansari N (2021) Impact of COVID-19 lockdown on NO2, O3, PM2.5 and PM10 concentrations and assessing air quality changes in Baghdad, Iraq. Sci Total Environ 754(2):141978. https://doi.org/10.1016/j.scitotenv.2020.141978
Hassan F, Chaudhry MU, Yasir M, Asghar MN, Sarkodie SA (2021) Monitoring the impact of COVID-19 lockdown on the production of nitrogen dioxide (No2) pollutants using satellite imagery: a case study of south Asia. Sustainability (Switzerland), 13. https://doi.org/10.3390/su13137184
Ho KF, Lee SC, Ho WK, Blake DR, Cheng Y, Li YS, Ho SSH, Fung K, Louie PKK, Park D (2009) Vehicular emission of volatile organic compounds (VOCs) from a tunnel study in Hong Kong. Atmos Chem Phys 9(19):7491–7504. https://doi.org/10.5194/ACP-9-7491-2009
Huang Z, Zhang Z, Kong W, Feng S, Qiu Y, Tang S, Xia C, Ma L, Luo M, Xu D (2017) Synergistic effect among Cl2, SO2 and NO2 in their heterogeneous reactions on gamma-alumina. Atmos Environ 166(2):403–411. https://doi.org/10.1016/j.atmosenv.2017.06.041
IQAir (2019) World Air Quality Report. 2019 World Air Quality Report,pp 1–35. https://www.iqair.com/world-most-polluted-cities/world-air-quality-report-2019-en.pdf
Jasaitis D, Vasiliauskiene V, Chadyšiene R, Pečiuliene M (2016) Surface ozone concentration and its relationship with UV radiation, meteorological parameters and radon on the Eastern Coast of the Baltic Sea. Atmosphere 7(2):27. https://doi.org/10.3390/ATMOS7020027
Jathar SH, Gordona TD, Hennigan CJ, Pye HOT, Pouliot G, Adams PJ, Donahue NM, Robinson AL (2014) Unspeciated organic emissions from combustion sources and their influence on the secondary organic aerosol budget in the United States. Proc Natl Acad Sci USA 111(29):10473–10478. https://doi.org/10.1073/PNAS.1323740111/-/DCSUPPLEMENTAL
Kerimray A, Baimatova N, Ibragimova OP, Bukenov B, Kenessov B, Plotitsyn P, Karaca F (2020) Assessing air quality changes in large cities during COVID-19 lockdowns: The impacts of traffic-free urban conditions in Almaty, Kazakhstan. Sci Total Environ, 730. https://doi.org/10.1016/J.SCITOTENV.2020.139179
Keywood MD, Varutbangkul V, Bahreini R, Flagan RC, Seinfeld JH (2004) Secondary organic aerosol formation from the ozonolysis of cycloalkenes and related compounds. Environ Sci Technol 38(15):4157–4164. https://doi.org/10.1021/ES035363O
Khan YA (2021) The COVID-19 pandemic and its impact on environment: the case of the major cities in Pakistan. Environ Sci Pollut Res 28(39):54728–54743. https://doi.org/10.1007/s11356-021-13851-4
Khattak P, Khokhar MF, Yasmin N (2014) Spatio-temporal analyses of atmospheric sulfur dioxide column densities over Pakistan by using SCIAMACHY Data. Aerosol Air Qual Res 14(7):1883–1896. https://doi.org/10.4209/aaqr.2013.12.0357
Li C, Huang Y, Guo H, Wu G, Wang Y, Li W, Cui L (2019) The concentrations and removal effects of PM10 and PM2.5 on a wetland in Beijing. Sustainability 11(5): 1312. https://doi.org/10.3390/SU11051312
Li G, Bei N, Tie X, Molina LT (2011) Aerosol effects on the photochemistry in Mexico City during MCMA-2006/MILAGRO campaign. Atmos Chem Phys 11(11):5169–5182. https://doi.org/10.5194/acp-11-5169-2011
Liu T, Huang DD, Li Z, Liu Q, Chan M, Chan CK (2018) Comparison of secondary organic aerosol formation from toluene on initially wet and dry ammonium sulfate particles at moderate relative humidity. Atmos Chem Phys 18(8):5677–5689. https://doi.org/10.5194/ACP-18-5677-2018
Liu Y, Zhou Y, Lu J (2020) Exploring the relationship between air pollution and meteorological conditions in China under environmental governance. Sci Reports 10(1): 1–11. https://doi.org/10.1038/s41598-020-71338-7
Luo J, Du P, Samat A, Xia J, Che M, Xue Z (2017) Spatiotemporal pattern of PM2.5 Concentrations in Mainland China and analysis of its influencing factors using geographically weighted regression. Sci Reports 7(1):1–14. https://doi.org/10.1038/srep40607
Mansha M, Ghauri B, Rahman S, Amman A (2012) Characterization and source apportionment of ambient air particulate matter (PM2.5) in Karachi. Sci Total Environ 425:176–183. https://doi.org/10.1016/j.scitotenv.2011.10.056
McDonald BC, Goldstein AH, Harley RA (2015) Long-term trends in California mobile source emissions and ambient concentrations of black carbon and organic aerosol. Environ Sci Technol 49(8):5178–5188. https://doi.org/10.1021/ES505912B/SUPPL_FILE/ES505912B_SI_001.PDF
Mehmood U, Azhar A, Qayyum F, Nawaz H, Tariq S, ul-Haq Z (2021) Air pollution and hospitalization in megacities: empirical evidence from Pakistan. Environ Sci Pollut Res. https://doi.org/10.1007/s11356-021-14158-0
Menon S, Unger N, Koch D, Francis J, Garrett T, Sednev I, Shindell D, Streets D (2008) Aerosol climate effects and air quality impacts from 1980 to 2030. Environ Res Lett 3(2):024004. https://doi.org/10.1088/1748-9326/3/2/024004
Misra P, Takigawa M, Khatri P, Dhaka SK, Dimri AP, Yamaji K, Kajino M, Takeuchi W, Imasu R, Nitta K, Patra PK, Hayashida S (2021) Nitrogen oxides concentration and emission change detection during COVID-19 restrictions in North India. Sci Reports 11(1):1–11. https://doi.org/10.1038/s41598-021-87673-2
Nakada LYK, Urban RC (2020) COVID-19 pandemic: Impacts on the air quality during the partial lockdown in São Paulo state, Brazil. Sci Total Environ 730:139087. https://doi.org/10.1016/J.SCITOTENV.2020.139087
Nichol JE, Bilal M, Ali AM, Qiu Z (2020) Air pollution scenario over China during COVID-19. Remote Sensing 12(13). https://doi.org/10.3390/rs12132100
Ogen Y (2020) Assessing nitrogen dioxide (NO2) levels as a contributing factor to coronavirus (COVID-19) fatality. Sci Total Environ 726:138605. https://doi.org/10.1016/j.scitotenv.2020.138605
Park G, Mun S, Hong H, Chung T, Jung S, Kim S, Seo S, Kim J, Lee J, Kim K, Park T, Kang S, Ban J, Yu DG, Woo JH, Lee T (2019) Characterization of emission factors concerning gasoline, LPG, and diesel vehicles via transient chassis-dynamometer tests. Appl Sci 9(8):1573. https://doi.org/10.3390/APP9081573
Park M, Joo HS, Lee K, Jang M, Kim SD, Kim I, Borlaza LJS, Lim H, Shin H, Chung KH, Choi YH, Park SG, Bae MS, Lee J, Song H, Park K (2018) Differential toxicities of fine particulate matters from various sources. Sci Reports, 8(1). https://doi.org/10.1038/S41598-018-35398-0
Paulson SE, Chung MY, Hasson AS (1999) OH radical formation from the gas-phase reaction of ozone with terminal alkenes and the relationship between structure and mechanism. J Phys Chem A 103(41). https://doi.org/10.1021/JP991995E
Pervaiz S, Javid K, Khan FZ, Zahid Y (2020) Preliminary assessment of air during COVID-19 Lockdown: an unintended benefit to environment. Environ Natural Resources 18(4):363–375. https://doi.org/10.32526/ennrj.18.4.2020.35
Qayyum F, Mehmood U, Tariq S, Haq Zul, Nawaz H (2021) Particulate matter (PM2.5) and diseases: an autoregressive distributed lag (ARDL) technique. Environ Sci Pollut Res. https://doi.org/10.1007/s11356-021-15178-6
Qayyum F, Tariq S, ul-Haq Z, Mehmood U, Zeydan Ö (2022) Air pollution trends measured from MODIS and TROPOMI: AOD and CO over Pakistan. J Atmos Chem 79(3):199–217. https://doi.org/10.1007/s10874-022-09436-1
Qi L, Nakao S, Tang P, Cocker DR (2010) Temperature effect on physical and chemical properties of secondary organic aerosol from m-xylene photooxidation. Atmos Chem Phys 10(8):3847–3854. https://doi.org/10.5194/ACP-10-3847-2010
Rasheed A, Aneja VP, Aiyyer A, Rafique U (2015) Measurement and analysis of fine particulate matter (PM2.5) in urban areas of Pakistan. Aerosol Air Qual Res 15(2):426–439. https://doi.org/10.4209/aaqr.2014.10.0269
Saathoff H, Naumann KH, Möhler O, Jonsson ÅM, Hallquist M, Kiendler-Scharr A, Mentel TF, Tillmann R, Schurath U (2009) Temperature dependence of yields of secondary organic aerosols from the ozonolysis of α-pinene and limonene. Atmos Chem Phys 9(5):1551–1577. https://doi.org/10.5194/ACP-9-1551-2009
Saffari A, Daher N, Shafer MM, Schauer JJ, Sioutas C (2014) Global perspective on the oxidative potential of airborne particulate matter: a synthesis of research findings. Environ Sci Technol 48(13):7576–7583. https://doi.org/10.1021/es500937x
Sharma S, Zhang M, Gao J, Zhang H, Harsha S (2020) Science of the total environment Effect of restricted emissions during COVID-19 on air quality in India. Sci Total Environ 728:138878. https://doi.org/10.1016/j.scitotenv.2020.138878
Shirazi SA, Kazmi SJH (2014) Analysis of population growth and urban development in Lahore-Pakistan using geospatial techniques: suggesting some future options. South Asian Stud 29(1):269–280
Stanier CO, Pathak RK, Pandis SN (2007) Measurements of the volatility of aerosols from alpha-pinene ozonolysis. Environ Sci Technol 41(8):2756–2763. https://doi.org/10.1021/ES0519280
Stavrakou T, Müller JF, Bauwens M, Doumbia T, Elguindi N, Darras S, Granier C, De Smedt I, Lerot C, Van Roozendael M, Franco B, Clarisse L, Clerbaux C, Coheur PF, Liu Y, Wang T, Shi X, Gaubert B, Tilmes S, Brasseur G (2021) Atmospheric impacts of COVID-19 on NOx and VOC levels over China based on TROPOMI and IASI satellite data and modeling. Atmosphere 12(8). https://doi.org/10.3390/atmos12080946
Stewart DJ, Almabrok SH, Lockhart JP, Mohamed OM, Nutt DR, Pfrang C, Marston G (2013) The kinetics of the gas-phase reactions of selected monoterpenes and cyclo-alkenes with ozone and the NO3 radical. Atmos Environ 70:227–235. https://doi.org/10.1016/J.ATMOSENV.2013.01.036
Stone E, Schauer J, Quraishi TA, Mahmood A (2010) Chemical characterization and source apportionment of fine and coarse particulate matter in Lahore, Pakistan. Atmos Environ 44(8):1062–1070. https://doi.org/10.1016/j.atmosenv.2009.12.015
Tariq S, Ul-Haq Z, Mahmood K, Rana AD (2018) Spatio-temporal distributions and trends of aerosol parameters over Pakistan using remote sensing. Appl Ecol Environ Res 16(3):2615–2637. https://doi.org/10.15666/AEER/1603_26152637
Tariq S, Ul-Haq Z, Ali M (2015) Analysis of optical and physical properties of aerosols during crop residue burning event of October 2010 over Lahore, Pakistan. Atmos Pollut Res 6(6):969–978. https://doi.org/10.1016/j.apr.2015.05.002
Tran HNQ, Mölders N (2011) Investigations on meteorological conditions for elevated PM2.5 in Fairbanks, Alaska. Atmos Res 1(99):39–49. https://doi.org/10.1016/J.ATMOSRES.2010.08.028
ul-Haq Z, Tariq S, Ali M, Mahmood K, Batool SA, Rana AD (2014) A study of tropospheric NO2 variability over Pakistan using OMI data. Atmos Pollut Res 5(4):709–720. https://doi.org/10.5094/APR.2014.080
ul-Haq Z, Tariq S, Ali M, Mahmood K, Rana AD (2016) Sulphur dioxide loadings over megacity Lahore (Pakistan) and adjoining region of Indo-Gangetic Basin. Int J Remote Sens 37(13):3021–3041. https://doi.org/10.1080/01431161.2016.1192701
Ul-Haq Z, Tariq S, Rana AD, Ali M, Mahmood K, Shahid P (2015) Satellite remote sensing of total ozone column (TOC) over Pakistan and neighbouring regions. Int J Remote Sens 36(4):1038–1054. https://doi.org/10.1080/01431161.2015.1007255
Unger N, Menon S, Shindell DT, Koch DM (2009) Impacts of aerosol indirect effect on composition Impacts of aerosol indirect effect on past and future changes in tropospheric composition Impacts of aerosol indirect effect on composition. Chem Phys Discuss (Vol. 9). www.atmos-chem-phys-discuss.net/9/4691/2009/
Wang P, Chen K, Zhu S, Wang P, Zhang H (2020) Severe air pollution events not avoided by reduced anthropogenic activities during COVID-19 outbreak. Resour Conserv Recycl 158:104814. https://doi.org/10.1016/j.resconrec.2020.104814
Wetchayont P, Hayasaka T, Khatri P (2021) Air quality improvement during covid-19 lockdown in bangkok metropolitan, thailand: effect of the long-range transport of air pollutants. Aerosol Air Qual Res 21(7):1–16. https://doi.org/10.4209/aaqr.200662
Xu K, Cui K, Young L-H, Hsieh Y-K, Wang Y-F, Zhang J, Wan S (2020a) Impact of the COVID-19 event on air quality in Central China. Aerosol Air Qual Res 20(5):915–929. https://doi.org/10.4209/aaqr.2020.04.0150
Xu L, Tsona NT, Du L (2021a) Relative humidity changes the role of SO2 in biogenic secondary organic aerosol formation. J Phys Chem Lett 12(30):7365–7372. https://doi.org/10.1021/ACS.JPCLETT.1C01550
Xu L, Tsona NT, Du L (2021b) Relative humidity changes the role of SO2 in biogenic secondary organic aerosol formation. J Phys Chem Lett 12(30):7365–7372. https://doi.org/10.1021/ACS.JPCLETT.1C01550/SUPPL_FILE/JZ1C01550_SI_001.PDF
Xu L, Tsona NT, You B, Zhang Y, Wang S, Yang Z, Xue L, Du L (2020) NOx enhances secondary organic aerosol formation from nighttime γ-terpinene ozonolysis. Atmos Environ 225(February). https://doi.org/10.1016/j.atmosenv.2020.117375
Xu WY, Zhao CS, Ran L, Deng ZZ, Liu PF, Ma N, Lin WL, Xu XB, Yan P, He X, Yu J, Liang WD, Chen LL (2011) Characteristics of pollutants and their correlation to meteorological conditions at a suburban site in the North China Plain. Atmos Chem Phys 11(9):4353–4369. https://doi.org/10.5194/ACP-11-4353-2011
Yang Z, Yang J, Li M, Chen J, Ou CQ (2021) Nonlinear and lagged meteorological effects on daily levels of ambient PM2.5 and O3: evidence from 284 Chinese cities. J Clean Prod 278. https://doi.org/10.1016/J.JCLEPRO.2020.123931
Yao L, Kong S, Zheng H, Chen N, Zhu B, Xu K, Cao W, Zhang Y, Zheng M, Cheng Y, Hu Y, Zhang Z, Yan Y, Liu D, Zhao T, Bai Y, Qi S (2021) Co-benefits of reducing PM 2.5 and improving visibility by COVID-19 lockdown in Wuhan. https://doi.org/10.1038/s41612-021-00195-6
Yue Y, Cheng J, Lee KS, Stocker R, He X, Yao M, Wang J (2022) Effects of relative humidity on heterogeneous reaction of SO2 with CaCO3 particles and formation of CaSO4·2H2O crystal as secondary aerosol. Atmos Environ 268:118776. https://doi.org/10.1016/J.ATMOSENV.2021.118776
Zhang M, Katiyar A, Zhu S, Shen J, Xia M, Ma J, Harsha Kota S, Wang P, Zhang H (2021) Impact of reduced anthropogenic emissions during COVID-19 on air quality in India. Atmos Chem Phys 21(5):4025–4037. https://doi.org/10.5194/acp-21-4025-2021
Zhang P, Chen T, Liu J, Liu C, Ma J, Ma Q, Chu B, He H (2019) Impacts of SO2, relative humidity, and seed acidity on secondary organic aerosol formation in the ozonolysis of butyl vinyl ether. Undefined 53(15):8845–8853. https://doi.org/10.1021/ACS.EST.9B02702
Zhang Q, Wu L, Fang X, Liu M, Zhang J, Shao M, Lu S, Mao H (2018a) Emission factors of volatile organic compounds (VOCs) based on the detailed vehicle classification in a tunnel study. Sci Total Environ 624:878–886. https://doi.org/10.1016/J.SCITOTENV.2017.12.171
Zhang Y, Yang W, Simpson I, Huang X, Yu J, Huang Z, Wang Z, Zhang Z, Liu D, Huang Z, Wang Y, Pei C, Shao M, Blake DR, Zheng J, Huang Z, Wang X (2018) Decadal changes in emissions of volatile organic compounds (VOCs) from on-road vehicles with intensified automobile pollution control: case study in a busy urban tunnel in south China. Environ Pollut (Barking, Essex : 1987) 233:806–819. https://doi.org/10.1016/J.ENVPOL.2017.10.133
Zhao D, Song X, Zhu T, Zhang Z, Liu Y, Shang J (2018) Multiphase oxidation of SO2 by NO2 on CaCO3 particles. Atmos Chem Phys 18(4):2481–2493. https://doi.org/10.5194/ACP-18-2481-2018
Zhou Y, Zhang H, Parikh HM, Chen EH, Rattanavaraha W, Rosen EP, Wang W, Kamens RM (2009) Secondary organic aerosol formation from xylenes and mixtures of toluene and xylenes in an atmospheric urban hydrocarbon mixture: Water and particle seed effects (II). Atmos Environ 45(23):3882–3890. https://doi.org/10.1016/J.ATMOSENV.2010.12.048
Zhou Y, Zhang H, Parikh HM, Chen EH, Rattanavaraha W, Rosen EP, Wang W, Kamens RM (2011) Secondary organic aerosol formation from xylenes and mixtures of toluene and xylenes in an atmospheric urban hydrocarbon mixture: Water and particle seed effects (II). Atmos Environ 45(23):3882–3890. https://doi.org/10.1016/J.ATMOSENV.2010.12.048
Zoran MA, Savastru RS, Savastru DM, Tautan MN (2020) Assessing the relationship between surface levels of PM2.5 and PM10 particulate matter impact on COVID-19 in Milan, Italy. Sci Total Environ 738:139825. https://doi.org/10.1016/j.scitotenv.2020.139825
Acknowledgements
We acknowledged the Environmental Protection Department (https://epd.punjab.gov.pk) for providing us with air pollutants datasets, (http://wunderground.com) for meteorological datasets and (https://www.ready.noaa.gov/) for backward trajectories and vertical stream profiles datasets.
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FQ conceptualizes the study and wrote the manuscript. ST conceptualizes the methodology and wrote the manuscript. Zul-H supervised the work and wrote the manuscript. HN, UM and ZBB wrote the manuscript.
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Qayyum, F., Tariq, S., Nawaz, H. et al. Variation of air pollutants during COVID-19 lockdown phases in the mega-city of Lahore (Pakistan); Insights into meteorological parameters and atmospheric chemistry. Acta Geophys. 72, 2083–2096 (2024). https://doi.org/10.1007/s11600-023-01208-z
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DOI: https://doi.org/10.1007/s11600-023-01208-z