Low- and middle-income groups are the worst affected by pollution; 92% of deaths due to pollution occurred in that income group
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/india-has-94-cities-toxic-air-half-them-just-four-states
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/business-standard-new-delhi
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/air-pollution
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/india
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/air-quality-standards
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/central-pollution-control-board-cpcb
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/rspm-pm-10
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/non-communicable-diseases
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/health-effects