Though Doon valley was once famous for its green and clean environment, the combination of environmental degradation and natural factors has created a situation wherein the quantity of dust and suspended particles of harmful chemicals in the air has reached a level that is up to four times more than the healthy limit.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/harmful-chemicals-atmosphere-can-cause-skin-respiratory-ailments
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/pioneer-new-delhi
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/air-pollution
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/spm
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/respiratory-diseases
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/skin-diseases
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/uttaranchal-uttarakhand
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/dehradun-d