BOSTON/NEW YORK, June 19, 2024 – Air pollution is having an increasing impact on human health and is the second leading risk factor for mortality worldwide, according to the fifth edition of the State of the Global Air (SoGA) report.
According to a report released today by the Health Effects Institute (HEI), an independent, US-based non-profit research institute, air pollution caused 8.1 million deaths worldwide in 2021. Beyond these deaths, millions of people are living with debilitating chronic diseases, placing an enormous strain on healthcare systems, economies and society.
The report, produced for the first time in partnership with UNICEF, finds that children under the age of five are particularly vulnerable, suffering from health consequences including premature birth, low birth weight, asthma and lung diseases. In 2021, exposure to air pollution was associated with more than 700,000 deaths among children under five, making it the second leading risk factor for mortality in this age group after malnutrition. Of these child deaths, an alarming 500,000 were linked to household air pollution from indoor cooking with polluting fuels, mainly in Africa and Asia.
Global health concerns
The new SoGA report provides an in-depth analysis of recently released data from the Global Burden of Disease Study 2021, showing that pollutants such as outdoor fine particulate matter (PM2.5), household air pollution, ozone (O3) and nitrogen dioxide (NO2) are severely impacting people's health around the world. The report includes data from more than 200 countries and territories around the world, showing that nearly every person on the planet inhales unhealthy levels of air pollution every day, which has far-reaching health impacts.
More than 90 percent of global air pollution deaths, or 7.8 million, are attributed to PM2.5 air pollution, which includes ambient PM2.5 and household air pollution. These particles, less than 2.5 micrometers in diameter, are so small that they can lodge in the lungs and enter the bloodstream, affecting many organ systems and increasing the risk of non-communicable diseases such as heart disease, stroke, diabetes, lung cancer and chronic obstructive pulmonary disease (COPD) in adults. According to the report, PM2.5 has been found to be the most consistent and accurate predictor of poor health outcomes worldwide.
“We hope that our 'State of the World's Air' report will provide both information and inspiration for change,” said HEI President Elena Kraft. “Air pollution has enormous health impacts, and we know that improving air quality and global public health is both realistic and achievable.”
Air pollution and climate change
PM2.5 air pollution is produced by the burning of fossil fuels and biomass in areas such as transportation, residential, coal-fired power plants, industrial activities and wildfires. These emissions not only affect people's health but also contribute to greenhouse gases that warm the planet. The most vulnerable people are disproportionately affected by both climate hazards and polluted air.
In 2021, long-term exposure to ozone was responsible for an estimated 489,518 deaths worldwide, including 14,000 deaths from ozone-related COPD in the United States, more than any other high-income country. As the world continues to warm due to climate change, ozone concentrations are expected to increase in areas with high NO2 concentrations, with even greater health impacts.
This year's report includes for the first time nitrogen dioxide (NO2) exposure levels and associated health effects, including the impact of NO2 exposure on the development of childhood asthma. Traffic exhaust is the main source of NO2, so NO2 exposure levels and health effects are often highest in densely populated urban areas, especially in high-income countries.
“This new report is a stark reminder of the significant impacts of air pollution on human health, with the burden falling disproportionately on young children, older people and low- and middle-income countries,” said Dr Pallavi Pant, head of global health at HEI, who oversaw the release of the SoGA report. “This highlights a clear opportunity for cities and countries to consider air quality and air pollution as high-risk factors when designing health policies and other non-communicable disease prevention and control programs.”
Children's Health
Children are hit hardest by the health effects of air pollution. They are particularly vulnerable to air pollution, where damage can begin in the womb and result in lifelong health consequences. For example, because children's lungs, bodies and brains are still developing, they inhale more air per kilogram of body weight and absorb more pollutants than adults.
Exposure to air pollution in young children leads to pneumonia (which causes one in five child deaths globally) and asthma, the most common chronic respiratory disease in older children. Inequalities in the impact of air pollution on children's health are stark: air pollution-related mortality rates for children under five in Eastern, Western, Central and Southern Africa are 100 times higher than for the same age group in high-income countries.
“Despite progress in maternal and child health, almost 2,000 children under the age of five die every day from health risks related to air pollution,” said UNICEF Deputy Executive Director Kitty van der Heyden. “Our inaction is having serious consequences for future generations, impacting their health and well-being across the lifespan. The global urgency is undeniable. It is essential that governments and companies take into account these estimates and locally available data to inform meaningful, child-centred action to reduce air pollution and protect children's health.”
Progress is being made
There is some good news in the SoGA report: Mortality among children under five has fallen by 53 percent since 2000, largely due to efforts to expand access to clean energy for cooking, improve access to health care and nutrition, and raise awareness of the harms associated with exposure to air pollution in the home.
Many countries, especially those with the most severe air pollution, are finally starting to address the problem head on. In regions such as Africa, Latin America and Asia, air quality control measures such as setting up air quality monitoring networks, implementing stricter air quality policies, and offsetting traffic-related air pollution by moving to hybrid and electric vehicles are having a measurable impact on pollution and leading to improved public health.
While progress has been measured, more can be done to stop air pollution from outweighing other health risks and continuing to be one of the greatest threats to millions of lives.
# # #
Notes to editors:
Air pollution is the second leading risk factor for death in both the global population as a whole and in children under the age of 5. The top five risk factors for death in each category are:
Global risk factors for mortality
Rank
World population total
Children under 5 years old
1
High blood pressure
malnutrition
2
Air pollution
Air pollution
3
tobacco
Water and Sanitation (WaSH)
Four
diet
High or low temperature
Five
High fasting blood sugar
Tobacco (passive smoking)
The State of the World's Air report was produced by the State of the World's Air Initiative, a collaboration between the Health Effects Research Institute and the Global Burden of Disease Project of the Institute for Health Metrics and Evaluation, in partnership with UNICEF.
The report is based on data from the Institute for Health Metrics and Evaluation's Global Burden of Diseases, Injuries and Risk Factors Study (GBD 2021), which collaborated with more than 10,000 researchers around the world to produce globally comparable estimates of the health impacts of 88 environmental, behavioral and dietary risk factors in 204 countries and territories.
With each update, the GBD study incorporates the latest scientific evidence and methods to refine its estimates of the disease burden (or population health impact) from air pollution and other risk factors. Please note that the data presented here are global estimates based on a variety of publicly available datasets and do not necessarily represent the datasets submitted by national governments to UN agencies. All GBD estimates are subject to a rigorous peer review process and the data are published in The Lancet.
