## 5 Conclusions  
### The Effect and Prospect of the APCP Action Plan  
The APCP Action Plan requires that the concentrations of inhalable particulate matter in cities at or above the prefecture level in China will be reduced by more than 10% in 2017 compared with 2012. The three areas of focus are the concentration of fine particles (\(PM_{2.5}\)) in Jing-Jin-Ji, Yangtze River Delta and Pearl River Delta is about 25%, 20% and 15% lower than that in 2012. Therefore, the policy is called the most stringent air pollution control system in history. From the perspective of controlling pollutant emissions, the average concentration of inhalable particulate matter (\(PM_{10}\)) in cities of all regions and above in China decreased by 22.7% in 2017 compared with 2013, and that of Jing-Jin-Ji, Yangtze River Delta and Pearl River Delta decreased 39.6%, 34.3% and 27.7% compared with 2013. During the period 2013-2017, the average \(PM_{2.5}\) concentration in China's 30 provinces decreased from 52.71 \(\upmu\)g/m\({}^{3}\) to 39.94 \(\upmu\)g/m\({}^{3}\). The average sulfur dioxide emissions from industrial enterprises decreased from 681,100 tons to 217,600 tons.  
The average discharge of environmental pollutants, such as industrial wastewater, fixed waste generation and carbon dioxide, has been effectively controlled. From the perspective of the impact of human health, some research found that after APCP Action Plan, the loss of human health caused by air pollution has decreased, which avoids the premature death of more than 60,000 people. According to the survey results of the willingness to pay method, the increased health benefits are estimated to be 54.97 billion yuan. Therefore, the APCP action plan not only effectively improves the environmental level of each region, promotes the sustainable development of the local economy, but also alleviates people's health crisis, and realizes the ecological mode of harmonious development between humans and nature.  
Although the APCP Action Plan has gained remarkable achievements, the control of air pollution is a long process, and more long-term and effective policies are necessary. For example, the APCP Action Plan focuses on inhalable particulate matter and fine particulate matter, but there are no specific restrictions on the emission of volatile organic compounds and ozone. It also lacks the control of mobile source pollution. Therefore, the specific emission control indicators of other air pollutants should be further added to further promote the air quality standards. Based on this, a more effective and scientific policy mix [47] should focus on precise policy implementation, strengthening source control, scientific promotion and long-term mechanism.  
Inspired by the APCP Action Plan, countries can consider the air remediation policies in key areas, adjust measures to local conditions step-by-step, and establish key prevention and control areas. When formulating environmental policies, various countries should combine sustainable development strategy and carbon-neutral concept at first. Secondly, it is necessary to make breakthroughs from the energy use structure and industrial structure of each region, reduce the utilization rate of fossil fuels, improve the utilization efficiency of new energy. Finally, different countries should enhance the level of scientific and technological innovation, which is conducive to the construction of innovative ecosystems, and realize the positive value of cocreation and mutual benefit.