Chennai Five north-eastern states along with Himachal Pradesh have been rated as the most environmentally sustainable states in the country, according to the Environmental Sustainable Index 2011 released today by a city-based think tank here.

The report rates Manipur, Nagaland, Arunachal Pradesh, Mizoram, Sikkim and Himachal Pradesh in the top slots in its Environmental Sustainable Index 2011. It was released by Centre for Development Finance (CDF), affiliated to Institute for Financial Management and Research.