Air pollution and control: Past, present and future

Abstract

The quality of air is closely related to everyone’s life. However, due to the intense industrialization and urbanization, air pollution has affected or is affecting the health of the public. Since the notorious London smog and the Los Angeles photochemical smog events, the air pollution has been developing rapidly in recent years in some developing countries such as China and India. The essence of air pollution hazard is the impact of air pollutants on human health and environment. In view of the fragmentation of the research and one-sided knowledge of someone on air pollution and control, this paper is documented to review the whole status of technology development in this research field, to clarify the formation and elimination mechanism of air pollution, to correctly understand the hazard of air pollution and to promote the precise management of air pollution control. The research of the air pollution hazard is essentially the study of the effect of atmospheric pollution on human health and environment. The past, present and future status of air pollution and its control will be reviewed in this paper from the perspective of physical, chemical and biological process which are be modeling using mathematical technique, coding and programing. Meanwhile, the history, present and existing problems on atmospheric physics, atmospheric chemistry, emission inventory, atmospheric environment monitoring, meteorological field forecast, air quality forecast, source apportionment and tracing source, the impact of air pollution on human health, and atmospheric pollution control are well summarized. From the classical analytical methods developed in the middle of the last century such as the Gaussian method to the numerical methods generally used so far, the physical processes of transmission, diffusion and sedimentation of pollutant are described and solved. The chemical processes represented by the London smog incident mainly sulfur compounds, by Los Angeles photochemical smog mainly O3 and nitrogenous compounds, and by Beijing-Tianjin-Hebei fog-haze pollution mainly mixture of nitrogen- containing compounds and sulfur-based compounds have made breakthrough progresses, and the chemical mechanism are basically clear. A series of biological effects will be occurred when the pollutants are inhaled. The chemical composition of air pollutants will have oxidative stress reactions, lipid peroxidation and DNA damage, causing inflammation, cardiovascular disease, cancer and birth defects. At present, the research on the physical process is relatively mature, and the accuracy and effective days of weather forecast are increasing and extending gradually. However, the two-way feedback mechanism of meteorology and atmospheric pollution is still a difficult issue. The understanding of the main chemical processes is basically clear, but a large number of unknown reaction mechanisms need to be further explored, especially the chemical mechanism of the explosive growth of PM2.5. Cognition of biological processes is still preliminary, which are based primarily on statistical analysis but lack a theoretical basis and are needed to be further explored. The theoretical framework, as well as core issues of air pollution hazard identification and control, are be put forward and pointed out based on the theories, techniques, methods and standards of inversion and generation of emission sources, particle toxicity identification, chemical process assimilation, health risk prediction and early warning, synchronization source apportionment of predicting results, and dynamic optimal control are not yet mature, which are the main focus for future development, due to the extremely complicated and staggered influence as well as constraints on physical process, chemical process, biological process as well as mathematical description and computer calculation principle of air pollution and prevention. If the toxicity of pollutants is directly related to health risks, which may provide more direct, effective and scientific technological support for air pollution emergency optimal control as well as the optimal issues of industrial, energy structure adjustment and heavy pollution sources layout, it will play a fundamental role to meet the objective needs of identifying accurately pollution sources, achieving targeted management and promoting ecological civilization construction.