China, India and Russia top the list of the world’s most polluted places, a study of global pollution found on Wednesday. The three countries are each home to two of the world’s top 10 polluted sites, while the others are in Peru, Ukraine, Zambia and Azerbaijan. Linfen and Tianying are the worst polluted places in China because of poor air quality and the metal industry respectively. Sukinda and Vapi are the worst in India, the former because of mining and the latter from general industry. Norilsk, where metals are extracted, and Dzerzhinsk, home to weapons manufacture, are Russia’s most polluted ­locations.