The debate over air pollution due to vehicular emissions is not new.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/stricter-emission-norms-only-paper
[2] http://admin.indiaenvironmentportal.org.in/category/author/rumu-banerjee
[3] http://admin.indiaenvironmentportal.org.in/category/newspaper/times-india-new-delhi
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/delhi
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/air-pollution
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/vehicles
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/pollution-under-control-certification
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/central-pollution-control-board-cpcb
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/vehicular-pollution
[10] http://admin.indiaenvironmentportal.org.in/category/thesaurus/cng
[11] http://admin.indiaenvironmentportal.org.in/category/thesaurus/vehicle-technology