Links:
[1] http://admin.indiaenvironmentportal.org.in/news/varanasi-has-only-one-air-quality-monitoring-station
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/hindu-new-delhi
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/uttar-pradesh
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/varanasi
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/air-quality-monitoring
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/central-pollution-control-board-cpcb