India's top pollution monitoring body, the Central Pollution Control Board, has said in a report that Delhi has the most polluted air among 16 cities in the National Capital Region.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/delhi-most-polluted-among-16-ncr-cities-cpcb-study
[2] http://admin.indiaenvironmentportal.org.in/category/author/urmi-goswami
[3] http://admin.indiaenvironmentportal.org.in/category/newspaper/economic-times-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/central-pollution-control-board-cpcb
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/nitrogen-dioxide
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/carbon-monoxide
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/cng
[10] http://admin.indiaenvironmentportal.org.in/category/thesaurus/delhi-pollution-control-committee-dpcc