CPCB monitored air quality at a total of 205 monitoring stations.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/poor-air-quality-across-41-cities-2015-says-cpcb-survey
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/daily-news-analysis-delhi
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/air-pollution
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/air-quality-standards
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/nitrogen-dioxide
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/air-quality-index-aqi
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/coimbatore-t
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/rajkot-t
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/ahmedabad-t
[10] http://admin.indiaenvironmentportal.org.in/category/thesaurus/central-pollution-control-board-cpcb