Concern department announced a surprised figure that recently near 2 million cases of excess deaths in developed countries perhaps caused by indoor air pollution. 4% of diseases in the world are related with the indoor environment. Statistics show that every year China has the excess number of deaths for 111,000, excess outpatients for 20,000 and excess emergency calls for 4.3 million. The heavy indoor pollution caused huge economic loss and that was US $10.7 billion in 1995...