A World Health Organization study published recently in the journal Climate and Atmospheric Science reports that half of the global population is currently exposed to increasing levels of air pollution, posing a significant public health crisis. According to the WHO, over 4.2 million deaths can be attributed to outdoor air pollution every year.
Air pollution is measured in part by the amount of particulate matter in the air, which is generated as a by-product of coal power plants, transportation emissions, agriculture, industry, and household energy use. Burning trash, deforestation, and sand and desert dust can also contribute to air pollution.
Because particulate matter is so small, it can travel through the respiratory tract into the lungs, exacerbating lung conditions like asthma. According to the WHO, worldwide ambient air pollution accounts for:
The study looked at trends of ground monitoring and satellite data of aerosol optical depth and chemical transport models to analyze global trends in air quality from 2010-2016. This wide-scale monitoring is in large part possible because of the United Nation's Sustainable Development Goal to expand the evidence base of the impacts of air pollution on health.
As lead researcher Professor Gavin Shaddick at the University of Exeter explains, "Although precise quantification of the outcomes of specific policies is difficult, coupling the evidence for effective interventions with global, regional and local trends in air pollution can provide essential information for the evidence base that is key in informing and monitoring future policies."
The study showed that certain regions of the world are more affected than others, notably Central, Eastern Southern and South-Eastern Asia. "While long-term policies to reduce air pollution have been shown to be effective in many regions, notably in Europe and the United States, there are still regions that have dangerously high levels of air pollution, some as much as five times greater than World Health Organization guidelines, and in some countries air pollution is still increasing," concludes Professor Shaddick, who is Chair of Data Science & Statistics.