China's cities continue to struggle with the effects of severe air pollution. Despite the warning and prevention systems which are attempting to curb the problem, millions of people still find themselves suffering under a thick cloud of hazardous smog.So, what impact is air pollution having on Chinese society? What measures can ordinary citizens take to protect themselves? And could big industries find that turning greener might actually make them more profitable? PIK speaks with Wu Changhua, Greater China Director of The Climate Group, an international non-profit organization, and Zha Daojiong, Professor of International Political Economy at the School of International Studies at Peking University.