Pollution is killing millions of people worldwide and, not surprisingly, India has topped the list in 2015, with 2.51 million people dying prematurely due to diseases linked to air, water and other forms of pollution, according to The Lancet, a reputed medical journal. The study said almost all pollution-related deaths - around 92% - are in poor or middle-income countries. And in rapidly industrialising countries such as India, Pakistan, China, Bangladesh, Madagascar, pollution is linked to as many as a quarter of all fatalities, reports Reuters.