Automobiles contribute significantly to the air pollution problem in urban areas. Their emissions account for approximately 60% of the total pollution in developed countries and about 80% in the developing countries.
Links:
[1] http://admin.indiaenvironmentportal.org.in/feature-article/air-quality-trans-gomti-area-lucknow-city-india
[2] http://www.springerlink.com/content/4nf6m8nqd7e3m5qb/
[3] http://admin.indiaenvironmentportal.org.in/category/author/verma
[4] http://admin.indiaenvironmentportal.org.in/category/author/s-n-singh-0
[5] http://admin.indiaenvironmentportal.org.in/category/author/m-k-shukla
[6] http://admin.indiaenvironmentportal.org.in/category/journal/bulletin-environmental-contamination-and-toxicology
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/urban-air-quality
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/lucknow-t
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/uttar-pradesh
[10] http://admin.indiaenvironmentportal.org.in/category/thesaurus/air-pollution
[11] http://admin.indiaenvironmentportal.org.in/category/thesaurus/vehicular-pollution