Singrauli, the powerhouse of India with massive coal reserves and many thermal power plants, should have been prosperous. But it is poor and polluted. People complain of unexplained ailments. Non-profit Centre for Science and Environment decided to investigate and found that mercury, a deadly toxin in coal, is slowly entering people's homes, food, water And even blood. Sugandh Juneja reports on the lab findings and how mercury affects people and environment