High levels of heavy-metal pollution have become a major public health hazard in China. Reports of children with high levels of lead in their bloodstream and villagers suffering from long-term exposure to heavy metals have been published frequently. There are increasing levels of mercury in food, surface waters, air and soil. Five key industries have been identified within the 12th Five Year Plan (2012-2016) as major causes of heavy metal pollution: heavy non-ferrous metal ore mining, heavy non-ferrous metal smelting, lead-acid battery manufacturing, leather and leather manufactured products, chemicals and chemical products. Emissions of power plants are reportedly another major source.