Data released by the World Health Organisation (WHO) has revealed that air pollution levels are dangerously high in many parts of the world. Most significantly, updated estimates reveal an alarming toll of 7m deaths every year can be associated with exposure to outdoor and household air pollution.
Professor Gavin Shaddick, from the University of Exeter, led the international team that produced the new estimates of global air quality. He said: “Air pollution presents a major risk to health worldwide. One of the key drivers of adverse health effects is fine particulate matter ambient pollution, or PM2.5, which are very small particles that that less than 2.5 microns in diameter. They can effect both our respiratory and cardio-vascular systems and are associated with very serious diseases including stroke, heart disease, lung cancer, chronic obstructive pulmonary diseases and respiratory infections.”
Major sources of air pollution from particulate matter include the inefficient use of energy by households, industry, the agriculture and transport sectors, and coal-fired power plants. In some regions, sand and desert dust, waste burning and deforestation are additional sources of air pollution.
More than 4,300 cities in 108 countries are now included in WHO’s ambient air quality database, making this the world’s most comprehensive database on ambient air pollution. However, although air pollution monitoring is increasing, there remain areas for which information isn’t available and estimates of exposures are required for all areas. The University of Exeter has been working with the WHO to create models that combine information from a number of different sources to allow exposures to be estimated worldwide.
Shaddick said: “We integrate measurements from ground monitoring with information from satellites, population estimates, land-use and other factors to allow us to provide estimates of air quality for every country and region, including those where there is little, or no, monitoring. This is essential for understanding the magnitude of the global risk to health. WHO air quality guidelines state that annual average levels (of PM2.5) should be below 10 micro-grams per meter cubed (μg/m3). We see great variability in air pollution across the world with some areas experiencing levels that are more than 5 times greater than WHO guidelines”.
Ambient (outdoor) air pollution is associated with 4.2m deaths in 2016, with household (indoor) air pollution from cooking with polluting fuels and technologies being associated with an estimated 3.8m deaths in the same period.
Dr Tedros Adhanom Ghebreyesus, director-general of WHO said: “Air pollution threatens us all, but the poorest and most marginalized people bear the brunt of the burden. It is unacceptable that more than 3bn people – most of them women and children – are still breathing deadly smoke every day from using polluting stoves and fuels in their homes. If we don’t take urgent action on air pollution, we will never come close to achieving sustainable development.”