Pollution Kills: The World's Deadliest, Unseen Threat

Air pollution is a leading cause of death worldwide, with nearly 9 million deaths attributed to it in 2015. In 2021, this figure was estimated to be 8.1 million, including 700,000 children under five. It is the second-highest risk factor for death globally, after high blood pressure, and is caused by the burning of unclean fuels and solid fuel stoves, as well as ambient air pollution. The impact of air pollution on health is far-reaching, with nearly every person on Earth breathing unhealthy levels of polluted air every day. It is a significant environmental and health issue, contributing to diseases such as stroke, heart disease, lung cancer, acute and chronic respiratory diseases, and diabetes.

Air pollution is the leading cause of death, with 8.1 million deaths in 2021

Air pollution is a combination of outdoor and indoor particulate matter and ozone. It is a risk factor for many of the leading causes of death, including heart disease, stroke, lower respiratory infections, lung cancer, diabetes, and chronic obstructive pulmonary disease (COPD). According to the State of Global Air (SoGA) report, air pollution accounted for 8.1 million deaths globally in 2021, becoming the second leading risk factor for death. This includes the deaths of children under five years old, with more than 500,000 linked to household air pollution due to cooking indoors with polluting fuels, mostly in Africa and Asia.

The report, produced by the State of Global Air Initiative in collaboration with the Health Effects Institute and the Institute for Health Metrics and Evaluation's Global Burden of Disease project, provides comparable estimates of the impact of environmental, behavioral, and dietary risk factors on health across 204 countries and territories. It is based on data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD 2021) and incorporates the latest scientific evidence and methods to refine estimates of the burden of disease from air pollution and other risk factors.

The impact of air pollution goes beyond early death, as it is also a significant contributor to the global disease burden. It affects not only the number of years lost due to premature death but also the quality of life for those living with poor health. Air pollution is a health and environmental issue across all countries, with large differences in severity. While death rates from total air pollution have declined in recent decades, improvements in outdoor pollution have been modest compared to those in indoor air pollution.

Sources of air pollution are multiple and context-specific, with major outdoor pollution sources including residential energy for cooking and heating, vehicles, power generation, agriculture/waste incineration, and industry. Indoor sources include household combustion devices and the burning of polluting fuels for cooking and heating. Policies and interventions that support sustainable land use, cleaner household energy, energy-efficient housing, and better waste management can help reduce ambient air pollution.

The World Health Organization (WHO) has identified air pollution as one of the key pillars of its 2022-25 strategy and has tightened its health-based global air quality guidelines. WHO also provides guidance on medical management and addresses key risks to health from indoor and outdoor air pollution, contributing to achieving health co-benefits from climate change mitigation policies.

9 million premature deaths annually are attributed to pollution

Air pollution is a combination of outdoor and indoor particulate matter and ozone. It is a major threat to health and climate, with smog hanging over cities and smoke inside homes. According to the World Health Organization (WHO), around 7 million premature deaths occurred worldwide in 2012 due to air pollution exposure, making it the world's largest single environmental health risk. This number has increased over the years, with 8.1 million deaths linked to air pollution in 2021.

The Lancet Commission on pollution and health reported that pollution was responsible for 9 million premature deaths in 2015, making it the leading environmental risk factor for disease and premature death. This estimate has been updated using data from the Global Burden of Diseases, Injuriaes, and Risk Factors Study 2019, and it was found that pollution remains responsible for approximately 9 million deaths per year, corresponding to one in six deaths worldwide.

Indoor air pollution, particularly in low- and middle-income countries, contributed to a significant number of these deaths. In 2012, around 4.3 million deaths were linked to indoor air pollution from households cooking over coal, wood, and biomass stoves. This issue is especially concerning for women and children, who spend more time at home breathing in the smoke and soot. Outdoor air pollution also takes a heavy toll, with 3.7 million deaths attributed to urban and rural sources in 2012.

The impact of air pollution on child health is particularly striking. In 2021, exposure to air pollution was linked to the deaths of over 700,000 children under five years old, with 500,000 of these deaths occurring due to household air pollution from cooking indoors with polluting fuels in Africa and Asia. UNICEF Deputy Executive Director Kitty van der Heijden emphasized the profound effects of air pollution on the next generation, with nearly 2,000 children under five dying daily due to health impacts linked to air pollution.

Air pollution is a critical global issue that demands urgent attention. It is a leading risk factor for death and contributes significantly to the global disease burden. By addressing air pollution, we not only improve public health but also contribute to the mitigation of climate change.

Lead poisoning and toxic chemical pollution cause 1.8 million deaths

Lead poisoning and toxic chemical pollution are significant contributors to the staggering number of pollution-related deaths worldwide. According to the Lancet Commission on Pollution and Health, pollution is responsible for approximately 9 million deaths annually, making it the leading environmental risk factor for premature mortality. While the overall death toll has remained relatively unchanged since 2015, the specific causes within the broader category of pollution have shifted.

The report highlights a decrease in deaths from household air pollution and water pollution, which are still the predominant causes of pollution-related deaths in Africa. However, these reductions have been offset by a concerning rise in deaths attributable to ambient air pollution and toxic chemical pollution. Notably, deaths from hazardous chemical pollutants have increased significantly, with an estimated 1.8 million deaths in 2019, representing a 66% increase since 2000.

Lead poisoning, a significant subset of toxic chemical pollution, is a pressing global health issue. Lead is a toxic metal found naturally in the Earth's crust, and its widespread use has led to extensive environmental contamination. Lead exposure has severe health consequences, particularly for children, who are more susceptible to its harmful effects. It can cause permanent brain damage, reduced intelligence, behavioural issues, and a range of health problems across multiple body systems, including the central nervous system and cardiovascular system.

The World Health Organization (WHO) estimates that lead exposure contributed to more than 1.5 million deaths in 2021, primarily due to cardiovascular effects. Additionally, lead exposure was estimated to result in over 33 million years lost to disability worldwide in the same year. WHO has identified lead as one of the top ten chemicals of major public health concern, emphasizing the need for action by member states to protect vulnerable populations, including children and women of reproductive age.

The impact of lead poisoning extends beyond immediate health concerns, as it also results in long-term economic consequences. The economic losses associated with pollution-related deaths in 2019 totaled $4.6 trillion, equivalent to 6.2% of global economic output. These losses highlight the far-reaching implications of pollution, affecting not only public health but also the economic stability and development of nations.

99% of the global population breathes air that exceeds WHO guidelines

Air pollution is one of the world's most pressing health and environmental issues, and it is a leading risk factor for death. In 2021, air pollution was responsible for 8.1 million deaths globally, including 500,000 children under the age of five. It has become the second-leading risk factor for death, threatening the health of almost the entire global population. According to the World Health Organization (WHO), 99% of people worldwide breathe air that exceeds internationally approved limits and is rife with particles that can enter the bloodstream, causing severe health issues.

WHO's 2022 update of its air quality database revealed that despite progress, the majority of cities still do not meet air quality guidelines. People living in these cities are exposed to unhealthy levels of fine particulate matter and nitrogen dioxide (NO2), with those in low and middle-income countries suffering the highest exposures. The database now includes over 6,000 municipalities and, for the first time, ground measurements of NO2 and particulate matter with diameters of 10 microns (PM10) or 2.5 microns (PM2.5). These pollutants originate primarily from human activities related to fossil fuel combustion, which WHO urges to be curbed.

The impact of air pollution goes beyond mortality, as it is also a leading contributor to the global disease burden. It affects not only the number of years lost due to early death but also the quality of life for those living with poor health. Air pollution is associated with various health risks, including heart disease, stroke, lower respiratory infections, lung cancer, diabetes, and chronic obstructive pulmonary disease (COPD). It is a significant concern in low-income countries, often ranking as the leading risk factor for death.

The problem of air pollution is not limited to outdoor sources; indoor (household) air pollution also plays a significant role. In Africa, household air pollution and water pollution are the predominant causes of pollution-related deaths. However, as African countries develop and industrialize, the number of deaths from ambient air pollution and air-pollution-related non-communicable diseases (NCDs) is increasing. This trend is particularly noticeable in rapidly emerging African economies.

The severity of air pollution varies across the world, with WHO's eastern Mediterranean and Southeast Asia regions having the poorest air quality, followed by Africa. The high number of preventable deaths and lost years of good health due to air pollution is unacceptable, and it underscores the urgent need to transition to cleaner and healthier energy systems.

90% of deaths from air pollution are due to non-communicable diseases

Air pollution is a leading risk factor for death, contributing to approximately 9 million deaths per year, or one in six deaths worldwide. It is a significant environmental and health issue, impacting not only the number of years lost due to early death but also the quality of life for those living with its effects.

Outdoor and indoor air pollution is responsible for an estimated 7 million deaths per year, second only to tobacco as a risk factor for non-communicable diseases (NCDs). According to the World Health Organization (WHO), one-quarter to one-third of deaths from heart disease, stroke, lung disease, and cancers are due to air pollution. This amounts to more than 6 million deaths in 2012 from ambient and household air pollution.

In particular, indoor air pollution, largely due to the use of solid fuels for cooking in low-income households, causes almost 4 million deaths annually, of which 3 million are attributed to NCDs. These include lung cancer, chronic obstructive pulmonary disease (COPD), ischaemic heart disease, and stroke. Ambient air pollution, on the other hand, is estimated to cause over 800,000 deaths from COPD and 280,000 deaths from lung cancer. Overall, 29% of COPD deaths are attributable to indoor air pollution, with an additional 8% from outdoor pollution and 11% in workplaces.

The impact of air pollution is not limited to respiratory and cardiovascular issues. It has been linked to various cancers, including bladder cancer, childhood leukaemia, and colorectal cancer. Air pollution also affects cognitive function, increasing the risk of dementia and contributing to delayed psychomotor development and lower child intelligence.

Addressing air pollution is crucial, and improvements in air quality can lead to immediate and tangible benefits, including increased infant birth weight, enhanced lung function in children, and reduced mortality rates.

Frequently asked questions