The CPCB said pollutants dispersed faster this year due to favourable weather conditions.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/air-quality-dipped-diwali-could-have-been-worse-if-not-favourable-weather
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/indian-express-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/diwali
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/festival
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/central-pollution-control-board-cpcb
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/rspm-pm-10
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/centre-science-and-environment-cse
[10] http://admin.indiaenvironmentportal.org.in/category/thesaurus/air-quality-standards