Introduction

Abstract

With the acceleration of economic development and urbanization, China is facing severe and combined air pollution problems, mainly including the increased atmos-pheric oxidation capacity and the frequent occurrence of haze. Satellite observations in 2009 showed that approximately 30% of China’s land area and nearly 800 million people were suffering from the haze, especially in the Beijing-Tianjin-Hebei Region (BTHR), the Yangtze River Delta, and the Pearl River Delta. Specifically, the occurrence frequency of haze in Beijing and Shanghai was more than 50%, and that in Guangzhou and Shenzhen also exceeded 30%. In 2010, the State Council’s Guiding Opinions on Promoting Joint Prevention and Control of Air Pollution and Improving Regional Air Quality clearly stated: “In recent years, regional air pollution problems such as acid rain, haze, and photochemical smog in some areas of China have become increasingly prominent, posing a serious threat to people’s health and environmental safety.”