Gases that escape from landfills contain pollutants that can cause cancer, asthma and other serious health hazards. Studies say that living near landfills can cause cancer because the escaping gases typically carry toxic chemicals such as paint thinners, solvents, pesticides, and other hazardous volatile organic compounds. Landfills are the largest global source of human-made methane emissions, a toxic climate-changing gas that is 25 to 72 times more potent than carbon dioxide. Some landfills have systems that attempt to capture the toxic gases they create. However, in India hardly any measures are taken to prevent the by-products of landfills from contaminating the air, ground water and soil.