caa a22 4500 467904677 CHVBK 20180406152830.0 cr unu---uuuuu 170328e20060401xx s 000 0 eng 10.1007/s10661-006-7051-5 doi (NATIONALLICENCE)springer-10.1007/s10661-006-7051-5 Assessment of Air Quality After the Implementation of Compressed Natural Gas (CNG) as Fuel in Public Transport in Delhi, India [Elektronische Daten] [Khaiwal Ravindra, Eric Wauters, Sushil Tyagi, Suman Mor, René Van Grieken] Public transport in Delhi was amended by the Supreme Court of India to use Compressed Natural Gas (CNG) instead of diesel or petrol. After the implementation of CNG since April 2001, Delhi has the highest fraction of CNG-run public vehicles in the world and most of them were introduced within 20 months. In the present study, the concentrations of various criteria air pollutants (SPM, PM10, CO, SO2 and NOx) and organic pollutants such as benzene, toluene, xylene (BTX) and polycyclic aromatic hydrocarbons (PAHs) were assessed before and after the implementation of CNG. A decreasing trend was found for PAHs, SO2 and CO concentrations, while the NOx level was increased in comparison to those before the implementation of CNG. Further, SPM, PM10, and BTX concentrations showed no significant change after the implementation of CNG. However, the BTX concentration demonstrated a clear relation with the benzene content of gasoline. In addition to the impact of the introduction of CNG the daily variation in PAHs levels was also studied and the PAHs concentrations were observed to be relatively high between 10 pm to 6 am, which gives a proof of a relation with the limited day entry and movement of heavy vehicles in Delhi. Springer Science + Business Media, Inc., 2006 CNG nationallicence public transport nationallicence CO nationallicence NOx nationallicence SO2 PM10 nationallicence BTX nationallicence PAHs nationallicence principal component analysis nationallicence Ravindra Khaiwal Micro and Trace Analysis Center, Department of Chemistry, University of Antwerp, Universiteitsplein 1, Antwerp, Belgium aut Wauters Eric Flemish Environment Agency (VMM), Krijgslaan 281, S2, Gent, Belgium aut Tyagi Sushil Central Pollution Control Board, Parivesh Bhawan, Delhi, India aut Mor Suman Centre for Energy Studies, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India aut Van Grieken René Micro and Trace Analysis Center, Department of Chemistry, University of Antwerp, Universiteitsplein 1, Antwerp, Belgium aut Environmental Monitoring and Assessment Kluwer Academic Publishers 115/1-3(2006-04-01), 405-417 0167-6369 115:1-3<405 2006 115 10661 https://doi.org/10.1007/s10661-006-7051-5 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10661-006-7051-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ravindra Khaiwal Micro and Trace Analysis Center, Department of Chemistry, University of Antwerp, Universiteitsplein 1, Antwerp, Belgium aut NATIONALLICENCE 700 1- Wauters Eric Flemish Environment Agency (VMM), Krijgslaan 281, S2, Gent, Belgium aut NATIONALLICENCE 700 1- Tyagi Sushil Central Pollution Control Board, Parivesh Bhawan, Delhi, India aut NATIONALLICENCE 700 1- Mor Suman Centre for Energy Studies, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India aut NATIONALLICENCE 700 1- Van Grieken René Micro and Trace Analysis Center, Department of Chemistry, University of Antwerp, Universiteitsplein 1, Antwerp, Belgium aut NATIONALLICENCE 773 0- Environmental Monitoring and Assessment Kluwer Academic Publishers 115/1-3(2006-04-01), 405-417 0167-6369 115:1-3<405 2006 115 10661 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer