Calcutta: The city had the highest rate of rise in the level of PM 2.5, an ultra-fine toxic pollutant, among the metros between 2014 and 2016, according to a World Health Organisation report.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/calcutta-tops-toxic-pollutant-rate-chart
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/telegraph-kolkata
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/west-bengal
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/kolkata
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/air-pollution
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/who
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/pm-25
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/rspm-pm-10
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/centre-science-and-environment-cse