sentences:  High secondary aerosol (particulates formed through atmospheric oxidation and reactions of gaseous organic compounds) contribution to particulate pollution in China is found.According to the U.S. Environmental Protection Agency, such fine particles can cause asthma, bronchitis, and acute and chronic respiratory symptoms such as shortness of breath and painful breathing, and may also lead to premature death.According to the World Bank, the Chinese cities with the highest levels of particulate matter in 2004 of those studied were Tianjin, Chongqing, and Shenyang.