While particulate matter, perhaps the most hazardous, has risen, other pollutants have fallen in the last five years
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/silver-lining-pollution-story
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/times-india-new-delhi
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/delhi
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/air-pollution
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/air-quality-monitoring
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/rspm-pm-10
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/carbon-monoxide
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/centre-science-and-environment-cse