Fluoride content high in areas depending on groundwater.
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/deeper-borewells-pose-fluoride-risk-hyderabad
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/deccan-chronicle-telangana
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/telangana
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/groundwater
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/hyderabad-t
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/fluoride
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/groundwater-pollution
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/water-pollution