Study: 99% of the world’s population is breathing harmful air

A study recently published in the journal The Lancet Planetary Health found that 99% of the world’s population is exposed to tiny, harmful air pollutants (known as PM 2.5), at levels harmful to health. “Almost no one is safe from air pollution.”said Yuming Guo, lead author of the study and a professor at Monash University. “The surprising result is that almost all parts of the world have average annual PM 2.5 concentrations higher than the air quality guidelines recommended by the World Health Organization.“. Particulate matter or PM 2.5 are very small particles – less than the thickness of a human hair – that can include dust, ash, soot, metal particles, cement and pollen, among others; from various sources, such as fossil fuel burning, industrial activity, agriculture and other activities. The effects on people’s health are associated with the exacerbation of respiratory diseases, such as bronchitis and pneumonia, and more recently their effects on the heart and blood vessels have also been demonstrated, increasing the risk of heart disease, stroke and other cardiovascular health problems. The latest studies suggest that this type of pollution, and particularly particles from urban traffic, is also associated with the increasing development of asthma and allergies among children. In the case of PM 2.5, their size makes them 100% breathable since they travel deep into the lungs, penetrating the respiratory system and depositing in the pulmonary alveoli, and can even reach the bloodstream. On the other hand, they are composed of elements that are more toxic (such as heavy metals and organic compounds) than those that compose, in general, the largest particles. Also, their size makes them lighter and therefore, generally, they remain longer in the air. In this sense, the study of the Australian university is the first to give information on the daily levels of harmful particles worldwide. The research team achieved this by combining traditional air quality monitoring observations, ground-based data from countries around the world, meteorological data from satellites, and machine learning to integrate all of the above, they explained in a press release. Among other things, they found that while daily levels declined in North America and Europe over the past two decades, they increased in South Asia, Australia, New Zealand, Latin America and the Caribbean, with more than 70% of days worldwide at levels above what is safe. According to Professor Guo, unsafe concentrations of PM 2.5 also show different seasonal patterns, “including northeastern China and northern India during the winter months (December, January and February), while areas of eastern North America had elevated levels of PM 2.5 in the summer months (June, July and August),” he said. He added: “We also recorded relatively high PM 2.5 air pollution in August and September in South America and June to September in sub-Saharan Africa.” Finally, he argued that the study is important because “It provides an in-depth understanding of the current state of outdoor air pollution and its impacts on human health. With this information, policymakers, public health officials, and researchers can better assess the short- and long-term health effects of air pollution and develop air pollution mitigation strategies.“.

Original source in Spanish