Half the world's population is exposed to increasing air pollution

Half the world's population is exposed to increasing air pollution, according to research from the University of Exeter (UK) published in the journal Nature Climate and Atmospheric Science.

The team of researchers, led by Professor Gavin Shaddick of Exeter University, managed to demonstrate the increasing levels of pollution to which large sections of the world's population are exposed.

The study, carried out in collaboration with the World Health Organization (WHO), found that this problem constitutes "a major, and in many areas (of the planet) increasing, threat to public health", despite "global efforts to improve air quality," the experts said.

Trends in global air quality between 2010 and 2016 were examined, taking into account policies implemented to reduce pollution in the short and long term.

Shaddick said it is "difficult" to concretely quantify the results of specific policies, but noted that combining evidence on effective interventions with global, regional and local trends in air pollution "can provide essential information" for designing and monitoring future actions.

The team used ground-based monitoring data along with satellite-based information on the optical depth of aerosols (a measure of the dispersion and absorption of visible light by particles in the atmosphere) and chemical transport models to produce annual air quality profiles for countries and regions.

The experts stressed that this methodology constitutes an important advance in the capacity to track progress towards the air quality indicators of the Sustainable Development Goals set by the UN, and also broadens the evidence base on the impact of this factor on health.

The WHO has estimated that over four million deaths annually can be attributed to pollution, which is generally caused by inefficient energy use in households, industry, deforestation, transport, and agricultural and coal-fired power plants.

Although air pollution affects high- and low-income countries alike, those with low and medium incomes experience a higher burden, with Asia being the continent with the highest concentrations.

"While long-term policies to reduce air pollution have proven effective in many regions, especially in Europe and the United States, there are still regions that have dangerously high levels of air pollution, some up to five times the WHO guidelines," Shaddick said.