127 Kumari Kumari Kumari Kumari Kumari et al et al et al et al et al / J. Env. Sci. Eng., 55(2), 2013 / J. Env. Sci. Eng., 55(2), 2013 / J. Env. Sci. Eng., 55(2), 2013 / J. Env. Sci. Eng., 55(2), 2013 / J. Env. Sci. Eng., 55(2), 2013 Emission Estimates of Particulate Matter and Heavy Emission Estimates of Particulate Matter and Heavy Emission Estimates of Particulate Matter and Heavy Emission Estimates of Particulate Matter and Heavy Emission Estimates of Particulate Matter and Heavy Metals from Mobile Sources in Delhi (India) Metals from Mobile Sources in Delhi (India) Metals from Mobile Sources in Delhi (India) Metals from Mobile Sources in Delhi (India) Metals from Mobile Sources in Delhi (India) RAGINI KUMARI 1,2+ , ARUN K. ATTRI 1 , LUC INT PANIS 2 AND B. R. GURJAR 3 An attempt has been made to make a comprehensive emission inventory of particulate matter (PM) of various size fractions and also of heavy metals (HMs) emitted from mobile sources (both exhaust and non-exhaust) from the road transport of Delhi, India (1991-2006). COPERT-III and 4 models were mainly used to estimate these emissions. Results show that the annual exhaust emission of PM of size upto 2.5 micrometer (PM 2.5 ) has increased from 3Gg to 4.5Gg during 1991-2006 irrespective of improvement in vehicle-technology and fuel use. PM emission from exhaust and non-exhaust sources in general has increased. Heavy commercial vehicles need attention to control particulate emission as it emerged as a predominant source of PM emissions. Among non-exhaust emissions of total suspended particulate matter (TSP), road-surface wear (~49%) has the prime contribution. As a result of introduction of unleaded gasoline Pb has significantly reduced (~8 fold) whereas share of Cu and Zn are still considerable. Among non- exhaust sources, Pb release was the most significant one from tyre-wear whereas from break-wear, Cu release was found to be the most significant followed by Pb and Cr + Zn. Because of public health concerns further policies need to be developed to reduce emissions of PM and HMs from the road transport of megacity Delhi. Key words : Key words : Key words : Key words : Key words : Heavy metals, non-exhaust, particulate matter, road transport emissions, megacity, Delhi Introduction Introduction Introduction Introduction Introduction Road transport is one of the major sources of particulate matter (PM) in urban areas (Gertler et al., 2000) 1 . Transport generated PM may vary in size, shape and chemical composition. For example, it can be constituted of different size fractions [e.g., PM 2.5 , PM 10 and total suspended particulate matter (TSP)] and chemical signatures (like heavy metals) depending upon the source (exhaust or non-exhaust), vehicle category, activity and/or fuel used (Furusjo et al., 2006) 2 . Heavy metals (HMs), too, are emitted not only from exhaust but also from non-exhaust sources like tyre-wear, road surface wear, brake wear, etc. 1 School of Environmental Sciences, Jawaharlal Nehru University (JNU), New Delhi-110 067, India 2 Flemish Institute for Technological Research (VITO) 200- Boeretang, 2400 Mol, Belgium 3 Department of Civil Engineering, Indian Institute of Technology Roorkee, Roorkee-247 667, India + Corresponding author: Dr. Ragini Kumari, Senior Programme Officer, Toxics Link, H2, Jungpura Ext., New Delhi-110 014, Phone : 011-24328006, Fax: 011-24321747; e-mail : raginivito@gmail.com Importance of emission estimation of PM and HMs in an urban area is many fold, e.g. health risk, pollution to ecosystem, soil and change in local to global climate. Personal exposure from transport related air pollution is more because of level of inhalation matches with tailpipe emissions (Kunzli et al., 2000) 3 . Inhalation of urban respirable PM is detrimental to human health not only because of its size but also due to chemical composition (Dahl et al., 2006) 4 . HMs emitted from transport, e.g., lead (Pb), nickel (Ni), chromium (Cr), and cadmium (Cd) cause serious health problems (WHO, 2000) 5 . That is the reason India’s Central Pollution Control Board (CPCB) has recently introduced ambient air quality standards (AAQS) of Nickel (Ni), Vanadium (V), Mercury (Hg), and Arsenic (As) in addition to the existing AAQS of Pb. J Environ. Science & Engg. Vol. 55, No. 2, p. 127-142, April 2013