Links:
[1] http://admin.indiaenvironmentportal.org.in/news/pollution-colour-periyar-changes-yet-again
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/new-indian-express-kochi
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/kerala
[4] http://admin.indiaenvironmentportal.org.in/category/thesaurus/periyar
[5] http://admin.indiaenvironmentportal.org.in/category/thesaurus/river-pollution
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/environmentalists
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/state-pollution-control-board-spcb-0
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/national-green-trbunal-ngt
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/water-pollution