Urban air pollution: an insight into its complex aspects

The increase in population, economic development, urbanization, industrialization and transport, has raised the issue of air pollution as one of the pressing concerns for contemporary society, primarily because of the harmful effects of elevated concentrations of polluting species on public health, environment and climate system which are still insufficiently understood. Despite the perennial intensive theoretical and experimental research, identifying and parsing the environmental factors that affect complex ecosystems with numerous inputs and outputs in subtle or severe ways, remain a challenge. The main reason lies in the fact that continuous burden on urban environment is governed not only by the increasingly intricate pollutant load, but also by pollution transport, dispersion and deposition processes, atmospheric chemistry, meteorological factors, topography, natural processes, etc. Moreover, containing not only gases, but also suspended particles and clouds, the atmosphere behaves as a colloidal medium. In this regard, researching the pollutant wet scavenging by atmospheric water is very important for revealing the environmental fate of air contaminants in atmospheric, terrestrial and aquatic systems.