A new study from the University of Exeter reports that half of the global population is exposed to increasing air pollution. Despite decades of efforts to improve air quality, pollution is only getting worse.
“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,” said study lead author Professor Gavin Shaddick.
According to the World Health Organization, outdoor air pollution is responsible for around 4.2 million premature deaths every year, and older populations have the highest death rates.
A growing collection of evidence shows that exposure to poor air quality is also detrimental to psychological well-being and cognitive function.
Industrial growth, agriculture, coal-fired power plants, vehicle emissions, and deforestation are all major sources of fine particulate matter pollution.
Low- and middle-income countries experience the highest burden, and the largest concentrations of pollutants are in central and southeastern Asia.
The WHO reports that 97 percent of cities in low- and middle- income countries do not meet air quality guidelines, but that percentage drops to 49 percent in high-income countries.
The research team analyzed air quality trends from 2010 and 2016 alongside short-term and long-term efforts to reduce air pollution.
“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,” said Professor Shaddick.
The research suggests that poor air quality is posing an even greater threat to public health in many areas. Rising levels of pollution elevate the risk of stroke, heart disease, lung cancer, and chronic and acute respiratory diseases, including asthma.
The study is published in the journal Climate and Atmospheric Science.