Study of seasonal and spatial variability among Benzene, Toluene, and p-Xylene (BTp-X) in ambient air of Delhi, India

Document Type : Original Research Paper


1 University School of Environment Management, Guru Gobind Singh Indraprastha University, Sector - 16 C, Dwarka, New Delhi – 110078, India

2 Central Pollution Control Board , Parivesh Bhawan, East Arjun Nagar, New Delhi - 110032, India


This study was carried out to analyze the variations of Benzene, Toluene, and para- Xylene (BTp-X) present in the urban air of Delhi. These pollutants can enter into the human body through various pathways like inhalation, oral and dermal exposure posing adverse effects on human health. Keeping in view of the above facts, six different locations of Delhi were selected for the study during summer and winter seasons (2016-2017). The concentrations of BTp-X on online continuous monitoring system were analyzed by chromatographic separation in the gaseous phase followed by their detection using a Photo Ionization Detector (PID). The concentrations of BTp-X were found maximum at a high traffic intersection area as 68.35±48.26 µg/m3 and 86.84±32.55 µg/m3 in summer and winter seasons respectively and minimum at a residential area as 4.34±2.48 µg/m3 and 15.42±9.8 µg/m3 in summer and winter seasons respectively. The average BTp-X concentrations of summer and winter seasons were found as 9.88, 20.68, 28.52, 49.75, 64.04, and 77.59 µg/m3 at residential, institutional, commercial, low traffic intersection, moderate traffic intersection and high traffic intersection areas respectively. Clearly, it has been found that the concentrations of these compounds were more on the traffic areas indicating that the vehicles are the major emission source. Hence, it may be concluded that the number of vehicles along with the high traffic congestion on the city streets and roads results in more accumulation of aromatic compounds and deteriorate the urban air quality.


Atkinson, R. (2000). Atmospheric chemistry of VOCs and NOx. Atmos. Environ., 34(12-14); 2063-2101.
ATSDR (Agency for Toxic Substances and Disease Registry). (2000). Toxicological Profile for Toluene. U.S. Department of Health and Human Services: Atlanta, GA, USA.
ATSDR (Agency for Toxic Substances and Disease Registry). (2005). Toxicological Profile for Xylene. U.S. Department of Health and Human Services: Atlanta, GA, USA.
ATSDR (Agency for Toxic Substances and Disease Registry). (2007). Toxicological Profile for Xylene. U.S. Department of Health and Human Services: Atlanta, GA, USA.
Badjagbo, K., Loranger, S., Moore, S., Tardif, R. and Sauve, S. (2010). BTEX exposures among automobile mechanics and painters and their associated health risks. Hum. Ecol. Risk. Assess., 16(2); 301-316.
Baimatova, N., Kenessov, B., Koziel, J. A., Carlsen, L., Bektassov, M. and Demyanenko, O. P. (2016). Simple and accurate quantification of BTEX in ambient air by SPME and GC–MS. Talanta., 154; 46-52.
Banerjee, T. and Srivastava, R. K. (2011). Evaluation of environmental impacts of Integrated Industrial Estate—Pantnagar through application of air and water quality indices. Environ. Monit. Assess., 172(1-4); 547-560.
Chen, X., Zhang, G., Zhang, Q. and Chen, H. (2011). Mass concentrations of BTEX inside air environment of buses in Changsha, China. Build. Environ., 46(2); 421-427.
CPCB (Central Pollution Control Board). (2009). Revised National Ambient Air Quality Standards. NAAQS Notification dated 18th November.
CPCB. (2003). Guidelines for ambient air quality monitoring. National Ambient Air Quality Monitoring Series (NAAQMS).
CPCB. (2012). Guidelines for the measurement of ambient air pollutants. Volume-II: guidelines for real time sampling & analyses CPCB, National Ambient Air Quality Series: NAAQMS/37/2012-13.
Dewangan, S., Chakrabarty, R., Zielinska, B. and Pervez, S. (2013). Emission of volatile organic compounds from religious and ritual activities in India. Environ. Monit. Assess., 185(11); 9279-9286.
DSH (Delhi Statistical Handbook). (2015). Directorate of Economics & Statistics. Government of National Capital Territory of Delhi.
Gaur, M., Singh, R. and Shukla, A. (2016). Variability in the Levels of BTEX at a Pollution Hotspot in New Delhi, India. J. Environ. Prot., 7(10); 1245-1258.
Hazrati, S., Rostami, R., Farjaminezhad, M. and Fazlzadeh, M. (2016). Preliminary assessment of BTEX concentrations in indoor air of residential buildings and atmospheric ambient air in Ardabil, Iran. Atmos. Environ., 132; 91-107.
Hoque, R. R., Khillare, P. S., Agarwal, T., Shridhar, V. and Balachandran, S. (2008). Spatial and temporal variation of BTEX in the urban atmosphere of Delhi, India. Sci. Total Environ., 392(1); 30-40.
IARC (International Agency for Research on Cancer). (2002). IARC Monographs Programme on Evaluation of Carcinogenic Risks to Humans.
Kerbachi, R., Boughedaoui, M., Bounoua, L. and Keddam, M. (2006). Ambient air pollution by aromatic hydrocarbons in Algiers. Atmos. Environ., 40(21); 3995-4003.
Keretetse, G. S., Laubscher, P. J., Du Plessis, J. L., Pretorius, P. J., Van Der Westhuizen, F. H., Van Deventer, E., Van Dyk, E., Eloff , F.C., Van Aarde, M.N. and  Du Plessis, L.H. (2008). DNA damage and repair detected by the comet assay in lymphocytes of African petrol attendants: a pilot study. Ann. Occup. Hyg., 52(7); 653-662.
Kim, Y. M., Harrad, S. and Harrison, R. M. (2001). Concentrations and sources of VOCs in urban domestic and public microenvironments. Environ. Sci. Technol., 35(6); 997-1004.
Majumdar, D., Dutta, C., Mukherjee, A. K. and Sen, S. (2008). Source apportionment of VOCs at the petrol pumps in Kolkata, India; exposure of workers and assessment of associated health risk. Trans. Res. D Trans. Environ., 13(8); 524-530.
Majumdar, D., Mukherjee, A. K. and Sen, S. (2011). BTEX in ambient air of a Metropolitan City. J. Environ. Prot., 2(01); 11-20.
Mukherjee, A. K., Bhattacharyam S. K., Ahmed, S., Roy, S. K., Roychowdhury, A. and  Sen, S. (2003). Exposure of drivers and conductors to noise, heat, dust and volatile organic compounds in the state transport special buses of Kolkata city. Trans. Res. D Trans. Environ., 8(1); 11-19.
Navasumrit, P., Chanvaivit, S., Intarasunanont, P., Arayasiri, M., Lauhareungpanya, N., Parnlob, V., Settachan, D. and Ruchirawat, M. (2005). Environmental and occupational exposure to benzene in Thailand. Chem. Biol. Interat., 153; 75-83.
Rad, H. D., Babaei, A. A., Goudarzi, G., Angali, K. A., Ramezani, Z. and Mohammadi, M. M. (2014). Levels and sources of BTEX in ambient air of Ahvaz metropolitan city. Air Qual. Atmos. Health., 7(4); 515-524.
Singh, A. K., Tomer, N. and Jain, C. L. (2012). Monitoring, assessment and status of benzene, toluene and xylene pollution in the urban atmosphere of Delhi, India. Res. J. Chem. Sci., 2(4); 45-49.
Singh, D., Kumar, A., Singh, B.P., Anandam, K., Singh, M., Mina, U., Kumar, K. and Jain, V.K. (2016). Spatial and temporal variability of VOCs and its source estimation during rush/non-rush hours in ambient air of Delhi, India. Air Qual. Atmos. Health., 9(5); 483-493.
Singh, R. K., Ramteke, D. S., Juneja, H. D. and Pandya, G.H. (2013). Ambient air quality monitoring in terms of volatile organic compounds (VOCs) occupational health exposure at petroleum refinery. Int. J. Environ. Prot., 3(7); 22-32.
Singla, V., Pachauri, T., Satsangi, A., Kumari, K.M. and Lakhani, A. (2012).  Comparison of BTX profiles and their mutagenicity assessment at two sites of Agra. India.  Sci. Wor. J., 12; 1-11.
Srivastava, A. (2005). Variability in VOC concentrations in an urban area of Delhi. Environ. Monit. Assess., 107(1-3); 363-373.
Srivastava, A., Joseph, A. E. and Devotta, S. (2006). Volatile organic compounds in ambient air of Mumbai-India. Atmos. Environ., 40(5); 892-903.
Truc, V. T. and Oanh, N. T. (2007). Roadside BTEX and other gaseous air pollutants in relation to emission sources. Atmos. Environ., 41(36); 7685-7697.
USEPA (U.S. Environmental Protection Agency). (1998). Hazardous Substance Research.
Wang, X. M., Sheng, G. Y., Fu, J. M., Chan, C. Y., Lee, S. C., Chan, L. Y. and Wang, Z. S. (2002). Urban roadside aromatic hydrocarbons in three cities of the Pearl River Delta, People's Republic of China. Atmos. Environ., 36(33); 5141-5148.
WHO (World Health Organization). (2010). Guidelines for Indoor Air Quality: Selected Pollutants. WHO Regional Office for Europe: Copenhagen, Denmark.
Woo, K., Park, H., Kang, T., Kim, G., Jeon, J., Jang, B., Lee, J. and Son, B. (2015). Concentration of volatile organic compounds (VOCs) in ambient air and level of residents in industrial area. J. Korean Soc. Occup. Environ. Hyg., 25(1); 104-114.