If a recent survey is to go by, the quality of air in Coimbatore has improved in the last two years, despite the rapid growth and development.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/coimbatoreans-get-breathe-some-clean-air
[2] http://admin.indiaenvironmentportal.org.in/category/author/p-sangeetha
[3] http://admin.indiaenvironmentportal.org.in/category/newspaper/times-india-coimbatore
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/tamil-nadu
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/coimbatore-t
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/air-pollution
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/state-pollution-control-board-spcb-0
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/air-quality-standards
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/environmentalists
[10] http://admin.indiaenvironmentportal.org.in/category/thesaurus/public-transport
[11] http://admin.indiaenvironmentportal.org.in/category/thesaurus/vehicular-pollution
[12] http://admin.indiaenvironmentportal.org.in/category/thesaurus/health-effects
[13] http://admin.indiaenvironmentportal.org.in/category/thesaurus/cng
[14] http://admin.indiaenvironmentportal.org.in/category/thesaurus/air-pollution-control