Published by the Health Effects Institute and the Institute for Health Metrics and Evaluation in partnership with UNICEF, provides a detailed analysis of air pollution’s health impacts globally, with a special focus on children. Using data from the Global Burden of Disease (GBD) 2021 study, it covers trends from 1990 to 2021 and highlights the urgent health crisis posed by air pollution.

Key Findings

• Global Mortality: Air pollution was the second leading risk factor for death globally in 2021, contributing to 8.1 million deaths. This includes over 700,000 deaths among children under five, making it the second leading cause of death for this age group after malnutrition.
• Health Impacts: Nearly 90% of the disease burden from air pollution stems from non-communicable diseases (NCDs) such as heart disease, stroke, diabetes, lung cancer, and chronic obstructive pulmonary disease (COPD). For children, exposure is linked to adverse birth outcomes, delayed brain development, asthma, and childhood cancers.
• Geographic Disparities: Low- and middle-income countries face the highest exposure to fine particulate matter (PM2.5), with South Asia and Africa experiencing the greatest disease burdens. Over 70% of child deaths are linked to air pollution in these regions due to household air pollution caused by burning solid fuels.
• Emerging Pollutants: For the first time, the report includes data on nitrogen dioxide (NO2), primarily linked to vehicle emissions. NO2 exposure disproportionately affects high-income countries’ urban areas but contributes significantly to global ozone formation.

Progress and Challenges

• Improvements: Since 2000, deaths from household air pollution have decreased by 36%, and PM2.5 levels are stabilizing or declining in some regions due to improved monitoring and mitigation efforts.
• Challenges: Despite progress, 99% of the global population still lives in areas with unhealthy PM2.5 levels. Climate change exacerbates air pollution through increased wildfires, dust storms, and ozone formation during heat waves.

Recommendations

1. Targeted Interventions: Prioritizing emission reductions in regions with high exposures.
2. Integrated Solutions: Addressing air pollution alongside climate change mitigation.
3. Enhanced Monitoring: Expanding air quality networks in underserved regions.
4. Global Investment: Increasing funding for clean air initiatives, particularly in low-income countries with limited resources.

Overview

Establishes access to a clean, healthy, and sustainable environment as a universal human right—particularly for children. Despite this recognition, billions of people still lack this fundamental right. In 2021, air pollution caused 8.1 million deaths, representing more than one in eight deaths globally. The report reveals the pervasive exposure to unhealthy air pollution levels worldwide, which leads to premature deaths and adverse health effects for millions.

Exposure to Air Pollution

Examines the complex nature of air pollution—a mix of particles and gases with varying sources and composition across regions and periods. Though air contains hundreds of chemical compounds, governments focus on monitoring key “criteria pollutants”: particulate matter (PM2.5), nitrogen dioxide (NO2), sulfur dioxide, ozone, and carbon monoxide. These substances are known to harm both human health and ecosystems. The report reveals that 99% of the global population lives in areas with unhealthy levels of PM2.5 pollution. In comparison, 34% reside in regions exceeding even the least stringent World Health Organization (WHO) interim air quality targets. It emphasizes the urgent need to address air pollution as a significant public health concern.

Exposure to Air Pollution

Explains how air pollution consists of various harmful particles and gases, with sources and composition that differ by location and time. While hundreds of chemical compounds exist in the air, governments focus on measuring key “criteria pollutants”—PM2.5, nitrogen dioxide (NO2), sulfur dioxide, ozone, and carbon monoxide. These pollutants have proven harmful effects on both human health and ecosystems.

According to alarming statistics, 99% of the global population lives in areas with unhealthy levels of PM2.5 pollution, while 34% reside in regions exceeding even the WHO’s least stringent interim air quality targets. These findings emphasize air pollution’s severe public health implications and the urgent need for effective measures to protect populations worldwide.

Air Pollution’s Burden of Disease

Examines how air pollution affects every major organ system in the human body. Both short-term and long-term exposure can cause serious health problems, including heart and lung diseases, diabetes, and adverse birth outcomes. In 2021, air pollution ranked as the second leading risk factor for early death globally—surpassed only by high blood pressure.

Discusses how the Global Burden of Disease (GBD) project utilizes epidemiological studies to estimate the disease burden from air pollution, quantifying deaths and years of healthy life lost across different countries. It notes that ongoing research continues to explore air pollution’s role in various diseases, including tuberculosis and neurodegenerative diseases, which are not currently included in GBD estimates. The report calls for a deeper understanding of the risks posed by air pollution to inform practical public health actions and policies to reduce its health burden.

Air Pollution and Children’s Health

Examines children’s heightened vulnerability to air pollution’s health impacts. It reveals that air pollution exposure—beginning even before birth—can impair brain development and raise the risk of autism spectrum disorder and long-term cognitive disabilities. The report also links air pollution to increased childhood cancer risks.

Additionally, it discusses the dangers of secondhand smoke, which poses serious health risks to children, including respiratory infections, ear infections, and exacerbation of asthma. It emphasizes that there is no safe level of exposure to secondhand smoke, and repeated exposure can lead to increased risks of cardiovascular diseases later in life. In 2021, secondhand smoke was identified as a major risk factor for deaths among children under five, resulting in approximately 39,000 fatalities. The report underscores the urgent need for protective measures to safeguard children’s health from the harmful effects of air pollution and secondhand smoke.

The Rising Threat of Noncommunicable Diseases

Examines the growing burden of NCDs—chronic diseases that don’t spread between people. Air pollution significantly contributes to these diseases, including cardiovascular diseases, cancer, diabetes, and chronic respiratory diseases. The report reveals that air pollution drives nearly 90% of the global disease burden through NCDs, primarily affecting older populations.

Emphasizes that while the overall contribution of air pollution to diseases like ischemic heart disease and stroke varies globally, it is exceptionally high in low- and middle-income countries (LMICs) compared to high-income countries (HICs). The report calls attention to the need for comprehensive strategies to address air pollution as a critical risk factor for NCDs, essential for improving public health outcomes and reducing mortality rates associated with these diseases.

Conclusions

Distills key findings about air pollution’s health impacts and stresses the urgent need for action. It emphasizes that air pollution continues to be a leading risk factor for premature death and disease worldwide, contributing heavily to non-communicable diseases (NCDs) and disproportionately affecting vulnerable populations, especially children.

Emphasizes implementing effective public health policies and interventions to reduce air pollution. It advocates for more significant investment in air quality monitoring, research, and public awareness campaigns to educate communities about air pollution’s health risks. The conclusions highlight how addressing air pollution improves health outcomes and advances broader objectives like climate change mitigation and sustainable development.

Key Resources

Provide references and details on the methodology from the Global Burden of Disease (GBD) study. It describes current methods for measuring exposure to fine particulate matter (PM2.5), ozone, and household air pollution. It details how researchers calculate premature deaths and disability-adjusted life years (DALYs) in this State of Global Air report.

Serves as a resource for readers seeking to understand the scientific basis behind the data presented in the report, including the analytical frameworks and statistical techniques used to assess air pollution’s health impacts. It emphasizes the importance of these methodologies in producing reliable and comparable global estimates that inform public health policies and interventions aimed at reducing air pollution’s disease burden.