There are many forms of air pollution. There is no doubt that air pollution is not healthy. The uncertainty is at what level is it an acceptable risk.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/air-pollution-and-heart-attacks
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/environment-news-network
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/air-pollution
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/health-effects
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/heart-diseases
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/pm-25
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/vehicular-pollution
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/industrial-pollution
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/diseases
[10] http://admin.indiaenvironmentportal.org.in/category/thesaurus/lung-disease
[11] http://admin.indiaenvironmentportal.org.in/category/thesaurus/lung-cancer
[12] http://admin.indiaenvironmentportal.org.in/category/thesaurus/who
[13] http://admin.indiaenvironmentportal.org.in/category/thesaurus/united-kingdom-uk