As the impact of rain subsided, Delhi's air quality deteriorated further and slipped into the 'very poor' category on Thursday, authorities said.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/delhis-air-pollution-rise-slips-very-poor-category-authorities
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/tribune-new-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/central-pollution-control-board-cpcb
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/rspm-pm-10
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/pm-25