What is air pollution?
Urban areas have problems with poor air quality. Pollutants include nitrogen oxides, volatile organic compounds, particulate matter, and photochemical oxidizers, which cause irreversible health problems for urban residents.
It is clear that urban air pollution is a serious environmental problem and its mitigation is a major societal challenge in the effort to create healthier cities (United Nations, 2015).
Particulate matter (PM) is a complex mixture of very small particles and liquid droplets consisting of acids, organic chemicals, metals, and soil or dust particles. PM sources are both natural and anthropogenic. Man-made sources of PM are combustion in mechanical and industrial processes, vehicle emissions and tobacco smoke (read more from the source).
Main sources
Wood burning is a major source of PM and is epidemiologically associated with adverse effects on lung health.
Wood stoves and coal burning are the single largest source of the pollutant PM2.5, producing far more emissions than industrial combustion and three times more than road transport. This type of pollution consists of small particles that are deeply absorbed into our diseases, chronic in the lungs and blood, and the World Health Organization, which is the most serious air pollutant for human health (read more from the source).
Major problem
Air pollution causes 9-12 million deaths per year worldwide
The biggest cause of air pollution is particulate matter ≤2.5 µg per cubic meter of air (PM2.5) from wood burning and vehicles (source).
99% of people globally breath in air with high level of pollutants, that exceeds WHO guidelines (source).