Variation of Quasi-Ultrafine Particle Concentrations During Odd–Even Traffic Restrictions in Delhi Shailendra Kumar Yadav, Monika Sharma, Kanagaraj Rajagopal, Vignesh Mohan, Veerendra Sahu, Rajeev Kumar Mishra, Bhola Ram Gurjar Clean Soil Air Water, 2026 The transportation sector is one of the major potential contributors to air pollution in urban regions, which is more harmful to human health. The concentration of quasi‐ultrafine particles is found to be higher in terms of number concentration but lower in terms of mass concentration. Delhi is known for its frequent pollution events, and various mitigation measures have been implemented over time to reduce the pollution load. The odd–even scheme for vehicular movement is one among several mitigation measures introduced for the third time in Delhi. Particle number concentration (PNC) variation during the implementation of the scheme was measured and analyzed in three major locations: Najafgarh, Pitampura, and Panchkuian. The study revealed that the quasi‐ultrafine PNC was reduced by around 30.4%, 30%, and 28.4%, respectively, in all three monitoring locations. The total vehicle count (TVC) showed a 26.7% reduction on odd days and a 24.9% reduction on even days, whereas reductions of 27.4% and 24.8% occurred in cars and taxis, respectively, for both odd and even days. In all locations, the concentration reduction obtained was greater on the odd days compared to the even days. Introducing such schemes will be beneficial in mitigating air pollution during extreme events, and source‐specific actions are necessary to achieve and maintain good air quality in the long run.
Impact of the odd–even scheme on particulate matter reduction in Delhi traffic intersections Kanagaraj Rajagopal, Vignesh Mohan, Monika Sharma, Shailendra Kumar Yadav, Veerendra Sahu, Rajeev Kumar Mishra, Sneha Gautam, Bhola Ram Gurjar, Prashant Kumar Particulate Science and Technology, 2026 This study investigates the impact of the third phase of the odd–even vehicle scheme on particulate matter (PM) concentrations at four traffic intersections in Delhi: Pitampura, Panchkuian Road, Najafgarh Road, and DTU Road. Parameters include PM10, PM2.5, PM1, and fine particles (inhalable, thoracic, and alveolar). Significant reductions in PM concentrations were observed, particularly on odd days. At Pitampura, for example, the maximum PM10 concentration recorded was 446 µg/m³ on a normal day, which reduced to 168 µg/m³ on an odd day (p < 0.05). The study reveals spatial variability in PM reduction, with more substantial decreases in city center locations. For instance, PM10 levels in Panchkuian Road reduced from 328.8 µg/m³ on a normal day to 262.6 µg/m³ on an odd day (p < 0.01). Meteorological parameters remained consistent, confirming that observed reductions were primarily due to the odd–even scheme. These findings underscore the scheme’s effectiveness in improving air quality, particularly in areas with high vehicular traffic, demonstrating a 41–49% reduction on odd days and 18–48% on even days for different PM sizes. This study highlights the need for targeted policies to address vehicular emissions and provides evidence supporting the odd–even scheme as a viable strategy for air quality improvement in urban environments.
Characterization of Red Sandstone and Black Crust to Analyze Air Pollution Impacts on a Cultural Heritage Building: Red Fort, Delhi, India Gaurav Kumar, Lucia Rusin, Pavan Kumar Nagar, Sanjay Kumar Manjul, Michele Back, Alvise Benedetti, Bhola Ram Gurjar, Chandra Shekhar Prasad Ojha, Mukesh Sharma, Eleonora Balliana Heritage, 2025 Urban air pollution poses significant risks to cultural heritage buildings, particularly in polluted megacities like Delhi, India. The Red Fort, a UNESCO World Heritage Site and a symbol of India’s rich history, is highly susceptible to degradation caused by air pollutants. Despite its great importance as an Indian and world heritage site, no studies have focused on characterizing its constituent materials or the degradation phenomena taking place. This study was developed in the framework of the MAECI (Italian Ministry of Foreign Affairs) and the Department of Science and Technology under the Ministry of Science and Technology, India, project: Indo—Italian Centre of Excellence for Restoration and Assessment of Environmental Impacts on Cultural Heritage Monuments. To understand their composition and degradation, Vindhyan sandstone and black crust samples were studied. Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM-EDX), X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) indicated that the red sandstone predominantly consisted of quartz and microcline, while the black crusts mainly comprised gypsum, bassanite, weddellite, quartz, and microcline. The analysis attributed the formation of gypsum to exogenous sources, such as construction activities and cement factory emissions. This pioneering study provides a basis for further research into the impacts of air pollution on Indian patrimony and promotes conservation strategies.
Assessment of Indoor Air Quality Across Microenvironments: Implications for Particulate Matter and CO2 Exposure Management Healthy Buildings Asia 2025, 2025
Particulate matter deposition in the human respiratory system: A health risk assessment at a technical university Journal of Air Pollution and Health, 2024
Extreme Concentrations of Nitric Oxide Control Daytime Oxidation and Quench Nocturnal Oxidation Chemistry in Delhi during Highly Polluted Episodes Beth S. Nelson, Daniel J. Bryant, Mohammed S. Alam, Roberto Sommariva, William J. Bloss, Mike J. Newland, Will S. Drysdale, Adam R. Vaughan, W. Joe F. Acton, C. Nicholas Hewitt, Leigh R. Crilley, Stefan J. Swift, Pete M. Edwards, Alastair C. Lewis, Ben Langford, Eiko Nemitz, Shivani, Ranu Gadi, Bhola R. Gurjar, Dwayne E. Heard, Lisa K. Whalley, Ülkü A. Şahin, David C. S. Beddows, James R. Hopkins, James D. Lee, Andrew R. Rickard, Jacqueline F. Hamilton Environmental Science and Technology Letters, 2023
Biogenic and anthropogenic sources of isoprene and monoterpenes and their secondary organic aerosol in Delhi, India Daniel J. Bryant, Beth S. Nelson, Stefan J. Swift, Sri Hapsari Budisulistiorini, Will S. Drysdale, Adam R. Vaughan, Mike J. Newland, James R. Hopkins, James M. Cash, Ben Langford, Eiko Nemitz, W. Joe F. Acton, C. Nicholas Hewitt, Tuhin Mandal, Bhola R. Gurjar, Ranu Gadi, James D. Lee, Andrew R. Rickard, Jacqueline F. Hamilton, and Atmospheric Chemistry and Physics, 2023
In situ ozone production is highly sensitive to volatile organic compounds in Delhi, India Beth S. Nelson, Gareth J. Stewart, Will S. Drysdale, Mike J. Newland, Adam R. Vaughan, Rachel E. Dunmore, Pete M. Edwards, Alastair C. Lewis, Jacqueline F. Hamilton, W. Joe Acton, C. Nicholas Hewitt, Leigh R. Crilley, Mohammed S. Alam, Ülkü A. Şahin, David C. S. Beddows, William J. Bloss, Eloise Slater, Lisa K. Whalley, Dwayne E. Heard, James M. Cash, Ben Langford, Eiko Nemitz, Roberto Sommariva, Sam Cox, Ranu Gadi, Bhola R. Gurjar, James R. Hopkins, Andrew R. Rickard, James D. Lee, and Atmospheric Chemistry and Physics, 2021
PM1 composition and source apportionment at two sites in Delhi, India, across multiple seasons Ernesto Reyes-Villegas, Upasana Panda, Eoghan Darbyshire, James M. Cash, Rutambhara Joshi, Ben Langford, Chiara F. Di Marco, Neil J. Mullinger, Mohammed S. Alam, Leigh R. Crilley, Daniel J. Rooney, W. Joe F. Acton, Will Drysdale, Eiko Nemitz, Michael Flynn, Aristeidis Voliotis, Gordon McFiggans, Hugh Coe, James Lee, C. Nicholas Hewitt, Mathew R. Heal, Sachin S. Gunthe, Tuhin K. Mandal, Bhola R. Gurjar, Ranu Gadi, Siddhartha Singh, Vijay Soni, James D. Allan, and Atmospheric Chemistry and Physics, 2021
Introduction to Biofuels Avinash Kumar Agarwal, Rashmi Avinash Agarwal, Tarun Gupta, Bhola Ram Gurjar Green Energy and Technology, 2017
Association of particulate matter emissions, air quality and health risks in South Asian cities Airborne Particles Origin Emissions and Health Impacts, 2017
Introduction Surampalli, Rao Y., Tian C. Zhang, R. D. Tyagi, Ravi Naidu, Bhola Ram Gurjar, et al. Carbon Capture and Storage Physical Chemical and Biological Methods, 2015
Carbon capture and storage: An overview Surampalli, Rao Y., Tian C. Zhang, R. D. Tyagi, Ravi Naidu, Bhola Ram Gurjar, et al. Carbon Capture and Storage Physical Chemical and Biological Methods, 2015
Preface Surampalli, Rao Y., Tian C. Zhang, R. D. Tyagi, Ravi Naidu, Bhola Ram Gurjar, et al. Carbon Capture and Storage Physical Chemical and Biological Methods, 2015
Urban and country level greenhouse gas emissions and carbon footprints: A comparative study of a megacity, Delhi and India. Journal of Environmental Science Engineering, 2011
Air quality in selected megacities Luisa T. Molina, Mario J. Molina, Robert S. Slott, Charles E. Kolb, Philip K. Gbor, Fan Meng, Rakesh B. Singh, Oscar Galvez, James J. Sloan, William P. Anderson, Xiaoyan Tang, Min Hu, Shaodong Xie, Min Shao, Tong Zhu, Y.H. Zhang, Bhola Ram Gurjar, Paulo E. Artaxo, Pedro Oyola, Ernesto Gramsch, Dario Hidalgo, Alan W. Gertler Journal of the Air and Waste Management Association, 2004
Variation of Quasi‐Ultrafine Particle Concentrations During Odd–Even Traffic Restrictions in Delhi SK Yadav, M Sharma, K Rajagopal, V Mohan, V Sahu, RK Mishra, ... CLEAN–Soil, Air, Water 54 (5), e70184 , 2026 2026
Black crust as a passive sampler of urban pollution on the heritage buildings in Delhi, India: An analytical and modelling approach G Kumar, BR Gurjar, M Sharma, CSP Ojha EGU26 , 2026 2026
An Analytical Approach to Characterize the Black Crust to Assess the Air Pollution Impact on Humayun’s Tomb, Delhi, India G Kumar, BR Gurjar, M Sharma, CSP Ojha International Journal of Architectural Heritage, 1-15 , 2026 2026
Impact of the odd–even scheme on particulate matter reduction in Delhi traffic intersections K Rajagopal, V Mohan, M Sharma, SK Yadav, V Sahu, RK Mishra, ... Particulate Science and Technology 44 (1), 14-25 , 2026 2026 Citations: 1
Characterization of Red Sandstone and Black Crust to Analyze Air Pollution Impacts on a Cultural Heritage Building: Red Fort, Delhi, India G Kumar, L Rusin, PK Nagar, SK Manjul, M Back, A Benedetti, BR Gurjar, ... Heritage 8 (6), 236 , 2025 2025 Citations: 3
Impact of allocation factors on spatial disaggregation of road traffic emissions in Megacity Delhi A Swarnkar, BR Gurjar, HK Suman Air Quality, Atmosphere & Health 18 (5), 1305-1325 , 2025 2025
on Frequency Adoption SS Kumar, HK Suman, RS Chalumuri, BR Gurjar Proceedings of the 7th International Conference of Transportation Research … , 2025 2025
Short-term forecasting of dissolved oxygen based on spatial-temporal Short-term forecasting of dissolved oxygen based on spatial-temporal attention mechanism and kernel-based … N Pant, D Toshniwal, BR Gurjar JOURNAL OF WATER PROCESS ENGINEERING 69 , 2025 2025
Short-term forecasting of dissolved oxygen based on spatial-temporal attention mechanism and kernel-based loss function N Pant, D Toshniwal, BR Gurjar Journal of Water Process Engineering 69, 106677 , 2025 2025 Citations: 7
Spatial distribution, sources, and health risk assessment of elements in road dust (< 20 μm) across Delhi R Jangirh, P Yadav, A Mondal, L Yadav, A Datta, P Saxena, E Nemitz, ... Atmospheric Pollution Research 16 (1), 102320 , 2025 2025 Citations: 6
Application of Eco-Friendly Submerged Vanes for Developing Inland Water Transport A Nayak, N Sharma, BR Gurjar, CSP Ojha International Conference on Transportation Planning and Implementation … , 2024 2024 Citations: 1
Forecasting Dissolved Oxygen Based on Two-Stage Decomposition with BiLSTM-Attention and weighted Huber Loss Function N Pant, D Toshniwal, BR Gurjar 2024 IEEE 11th International Conference on Data Science and Advanced … , 2024 2024 Citations: 1
Wintertime source apportionment of PM 2.5 pollution in million plus population cities of India using WRF-Chem simulation R Jat, BR Gurjar, SD Ghude, PP Yadav Modeling Earth Systems and Environment 10 (5), 6065-6082 , 2024 2024 Citations: 5
Framework for Application of Bamboo-Based Eco-friendly Submerged Vanes for Developing Inland Water Transport in India A Nayak, N Sharma, BR Gurjar, CSP Ojha International Conference on Transportation System Engineering and Management … , 2024 2024
Road Density-Based Model for Spatial Allocation of Vehicular Emissions A Swarnkar, BR Gurjar, HK Suman International Conference on Transportation System Engineering and Management … , 2024 2024
Multi-step forecasting of dissolved oxygen in River Ganga based on CEEMDAN-AdaBoost-BiLSTM-LSTM model N Pant, D Toshniwal, BR Gurjar Scientific Reports 14 (1), 11199 , 2024 2024 Citations: 16
Particulate matter deposition in the human respiratory system: A health risk assessment at a technical university S Khan, V Sahu, NM Kumar, BR Gurjar Journal of Air Pollution and Health , 2024 2024 Citations: 4
Exposure assessment of particulate matter during various construction activities in Kanpur City, India AK Rathi, D Parmar, R Ganguly, BR Gurjar, V Bhadauria International Journal of Environmental Science and Technology 21 (5), 5219-5230 , 2024 2024 Citations: 9
Emission inventory of inorganic trace gases from solid residential fuels over the National Capital Territory of India R Arya, S Ahlawat, L Yadav, M Rani, A Mondal, R Jangirh, G Kotnala, ... Environmental Science and Pollution Research 31 (3), 4012-4024 , 2024 2024 Citations: 6
A System for Assessing the LOS Given to e-Moped in Mixed Traffic Based on Frequency Adoption S Saurabh Kumar, HK Suman, RS Chalumuri, BR Gurjar Conference of Transportation Research Group of India, 137-150 , 2023 2023
MOST CITED SCHOLAR PUBLICATIONS
Evaluation of emissions and air quality in megacities BR Gurjar, TM Butler, MG Lawrence, J Lelieveld Atmospheric environment 42 (7), 1593-1606 , 2008 2008 Citations: 734
Human health risks in megacities due to air pollution BR Gurjar, A Jain, A Sharma, A Agarwal, P Gupta, AS Nagpure, ... Atmospheric Environment 44 (36), 4606-4613 , 2010 2010 Citations: 517
Air pollution trends over Indian megacities and their local-to-global implications BR Gurjar, K Ravindra, AS Nagpure Atmospheric Environment 142, 475-495 , 2016 2016 Citations: 476
Emission estimates and trends (1990–2000) for megacity Delhi and implications BR Gurjar, JA Van Aardenne, J Lelieveld, M Mohan Atmospheric Environment 38 (33), 5663-5681 , 2004 2004 Citations: 372
Role of meteorology in seasonality of air pollution in megacity Delhi, India SK Guttikunda, BR Gurjar Environmental monitoring and assessment 184 (5), 3199-3211 , 2012 2012 Citations: 318
Air pollution: health and environmental impacts BR Gurjar, LT Molina, CSP Ojha CRC press , 2010 2010 Citations: 234
Water pollution, human health and remediation K Jayaswal, V Sahu, BR Gurjar Water remediation, 11-27 , 2017 2017 Citations: 193
Assessment of urban heat island effect for different land use–land cover from micrometeorological measurements and remote sensing data for megacity Delhi M Mohan, Y Kikegawa, BR Gurjar, S Bhati, NR Kolli Theoretical and applied climatology 112 (3), 647-658 , 2013 2013 Citations: 189
The representation of emissions from megacities in global emission inventories TM Butler, MG Lawrence, BR Gurjar, J Van Aardenne, M Schultz, ... Atmospheric Environment 42 (4), 703-719 , 2008 2008 Citations: 183
Microalgae: An emerging source of energy based bio-products and a solution for environmental issues R Katiyar, BR Gurjar, S Biswas, V Pruthi, N Kumar, P Kumar Renewable and Sustainable Energy Reviews 72, 1083-1093 , 2017 2017 Citations: 182
Regional pollution potentials of megacities and other major population centers MG Lawrence, TM Butler, J Steinkamp, BR Gurjar, J Lelieveld Atmospheric Chemistry and Physics 7 (14), 3969-3987 , 2007 2007 Citations: 166
Estimation of exhaust and non-exhaust gaseous, particulate matter and air toxics emissions from on-road vehicles in Delhi AS Nagpure, BR Gurjar, V Kumar, P Kumar Atmospheric environment 127, 118-124 , 2016 2016 Citations: 152
New directions: can a “blue sky” return to Indian megacities? P Kumar, S Jain, BR Gurjar, P Sharma, M Khare, L Morawska, R Britter Atmospheric environment 71, 198-201 , 2013 2013 Citations: 145
Preliminary estimates of nanoparticle number emissions from road vehicles in megacity Delhi and associated health impacts P Kumar, BR Gurjar, AS Nagpure, RM Harrison Environmental Science & Technology 45 (13), 5514-5521 , 2011 2011 Citations: 142
New directions: megacities and global change BR Gurjar, J Lelieveld Atmospheric Environment 39 (2), 391-393 , 2005 2005 Citations: 138
Urban heat island assessment for a tropical urban airshed in India S Bhati, A Kandya, M Mohan, Y Kikegawa, B Gurjar Atmosphere and Climate Sciences , 2012 2012 Citations: 137
Human health risks in national capital territory of Delhi due to air pollution AS Nagpure, BR Gurjar, JC Martel Atmospheric Pollution Research 5 (3), 371-380 , 2014 2014 Citations: 123
Nanotechnology for agricultural applications: Facts, issues, knowledge gaps, and challenges in environmental risk assessment D Singh, BR Gurjar Journal of Environmental Management 322, 116033 , 2022 2022 Citations: 113
Characterization of dye-decolorizing peroxidase from Bacillus subtilis P Dhankhar, V Dalal, JK Mahto, BR Gurjar, S Tomar, AK Sharma, ... Archives of Biochemistry and Biophysics 693, 108590 , 2020 2020 Citations: 92
Traffic induced emission estimates and trends (2000–2005) in megacity Delhi AS Nagpure, K Sharma, BR Gurjar Urban Climate 4, 61-73 , 2013 2013 Citations: 83