Earth Today | Bad air plagues poorer countries
Published:Thursday | September 12, 2024 | 12:08 AM
A NEW report tracking air quality has revealed that poorer countries have up to four times higher levels of exposure to fine particulates in the air than their more well-to-do global neighbours.
“Fine particle air pollution, or PM2.5, refers to airborne particles measuring less than 2.5 micrometres in diameter (less than a 30th of the diameter of a human hair). These particles, as well as precursor chemicals that contribute to their formation in the atmosphere, are emitted from vehicles, residential fuel use, coal-burning power plants, agricultural and industrial activities, waste burning, wildfires, and many other human and natural sources,” explained the 2024 State of Global Air report.
“In low- and middle-income countries, exposures are between one and four times higher compared to those in high-income countries. In large part, these regional trends track closely with socioeconomic development and national policy actions,” the report said.
“Worldwide, eight of the 10 countries with the highest PM2.5 exposures are in Africa, and the remaining two are in the Middle East. At the regional level, major sources of PM2.5 in the Middle East and North Africa include dust, power plants, transportation, and industries, while South Asia has some of the largest PM2.5 exposure due to residential fuel use, energy generation, industries, and agriculture,” it said further.
Meanwhile, the health implications of exposure to PM2.5 are potentially dire.
“Among the key air pollutants that are currently measured, long-term exposure to PM2.5 is the most consistent and accurate predictor of poor health outcomes across populations,” the report said.
“Recent studies, including several from the Health Effects Institute conducted in Europe, Canada, and the United States, have shown that even people living in areas with very low levels of PM2.5 can still experience adverse health effects,” added the publication, which constitutes a special report on global exposure to air pollution and its health impacts, including on children.
But there is some good news, in that the levels are decreasing or stabilising in various regions, in accordance with World Health Organization guidelines. For example, in South Asia, Southeast and East Asia and Oceania, and “especially China, Central and Eastern Europe, and Central Asia”, the report said they have seen reductions in PM2.5 exposures in the last two decades.
Still, it cautioned that the journey to clear, clean air for all continues, particularly as air pollution is the second-leading cause of early death worldwide, “surpassed only by high blood pressure”.
“To reduce the disease burden attributable to air pollution exposure, we need to understand air pollution’s major sources, both now and in the future. This is the critical first step towards identifying the highest priority actions for air quality emissions control and the most cost-effective solutions to protect public health,” the report said.
State of Global Air 2024 was published through the collaborative efforts of the Health Effects Institute and the Institute for Health Metrics and Evaluation’s Global Burden of Disease project, in partnership with the United Nations Children’s Fund.