The impact of haze weather on health: a view to future.

In January 2013,China suffered large-scale haze weather four times,affecting 30 cities in all.The average number of haze weather days in many regions was higher than the same period in every year since 1961.PM2.5,which is defined as fine particulate matter with an aerodynamic diameter of2.5 micrometers or less,is the main health hazard in the context of haze weather.It can carry large amounts of poisonous and harmful substances,and penetrate deep into the lungs and blood circulation through the respiratory tract,thereby affecting human health.The Global Burden of Disease Study 2010 ranked