Deadly Pollution: Global Fatality Causes

Air pollution is a leading cause of death globally, with 8.1 million deaths recorded in 2021. It is a combination of outdoor and indoor particulate matter and ozone, which results in strokes, heart disease, lung cancer, acute and chronic respiratory diseases, and pneumonia in children. According to the World Health Organization (WHO), 99% of the global population breathes air that exceeds its guideline limits on pollutant levels. While indoor air pollution has seen an impressive decline, outdoor air pollution has only improved modestly. The economic burden of pollution-related premature mortality is significant, with air pollution costing the world an estimated $8.1 trillion in 2019, equivalent to 6.1% of global GDP.

Ambient air pollution

In 2016, ambient air pollution was responsible for an estimated 4.2 million deaths worldwide. This number increased to 4.2 million premature deaths per year in 2019, with 89% of those deaths occurring in low- and middle-income countries, particularly in the WHO South-East Asia and Western Pacific Regions. The latest burden estimates reflect the significant role of ambient air pollution in cardiovascular illness and death. It is estimated to cause about 16% of lung cancer deaths, 25% of chronic obstructive pulmonary disease (COPD) deaths, about 17% of ischaemic heart disease and stroke, and about 26% of respiratory infection deaths.

The sources of ambient air pollution are diverse and include residential energy use for cooking and heating, vehicles, power generation, agriculture/waste incineration, and industry. Fine particulate matter, which has the greatest impact on human health among all air pollutants, is primarily produced by fuel combustion in vehicles, power plants, industry, and biomass burning.

The effects of ambient air pollution are not limited to physical health issues. Exposure to air pollution during childhood has been linked to pneumonia and asthma, with the death rate from pneumonia in children under five years old being 100 times higher in Africa than in high-income countries. Additionally, air pollution has been associated with an increased risk of non-communicable diseases in adults, such as heart disease, stroke, diabetes, lung cancer, and chronic obstructive pulmonary disease (COPD).

To address the issue of ambient air pollution, policies and investments that support sustainable land use, cleaner household energy, cleaner transport, energy-efficient homes, improved power generation, and better municipal waste management are necessary. These measures can effectively reduce key sources of ambient air pollution and improve public health and environmental outcomes.

Household air pollution

Air pollution is a significant global issue, causing an estimated 8.1 million deaths worldwide in 2021. It is the second-leading risk factor for death, including for children under five. Household air pollution is a major contributor to this figure, with around 2.1 billion people worldwide cooking with inefficient and polluting fuels and technologies. These include open fires and inefficient stoves fuelled by kerosene, biomass (wood, animal dung, and crop waste), and coal. This generates harmful household air pollution, leading to an estimated 3.2 million deaths per year, including over 237,000 children under the age of five.

In addition to the direct health impacts, household air pollution also poses safety risks, especially for children. Kerosene ingestion is the leading cause of childhood poisoning, and open fires or unstable stoves can result in burns and scalds, causing serious injuries and deaths. The use of inefficient fuels and technologies for cooking, heating, and lighting also increases the risk of musculoskeletal damage from carrying heavy loads and the risk of injury or violence when collecting fuel, especially in insecure areas.

To address household air pollution, it is essential to expand the use of clean fuels and technologies. This includes solar, electricity, biogas, liquefied petroleum gas (LPG), natural gas, alcohol fuels, and improved biomass stoves that meet emission targets. WHO provides technical support and capacity building to countries to evaluate and scale up the use of health-promoting household fuels and technologies, as well as developing guidelines for indoor air quality and household fuel combustion.

Water pollution

Unsafe drinking water and inadequate sanitation are ancient scourges that have long threatened public health. In 2022, an estimated 1.7 billion people worldwide relied on drinking water sources contaminated with faeces, which can lead to fatal diseases. Microbiologically contaminated drinking water can transmit diseases such as diarrhoea, cholera, dysentery, typhoid, and polio. Diarrhoeal diseases alone are estimated to cause approximately 505,000 deaths each year, including 395,000 children under the age of five.

The natural presence of chemicals in groundwater, such as arsenic and fluoride, can also pose significant health risks. Additionally, other chemicals, such as lead, may elevate drinking water due to leaching from water supply components. Lead pollution has been responsible for around 900,000 premature deaths annually, with an estimated total of 1.8 million deaths caused by lead and other chemicals combined.

The inadequate management of urban, industrial, and agricultural wastewater further exacerbates water pollution. In 2021, over 2 billion people lived in water-stressed countries, and this number is expected to grow due to climate change and population growth. While the reuse of wastewater can be a beneficial strategy, it must be done safely and with sufficient treatment to protect human and environmental health.

Water-related diseases are largely preventable. The World Health Organization (WHO) plays a crucial role in addressing water pollution by leading global efforts to prevent water-related diseases and advising governments on developing health-based targets and regulations. WHO's water quality guidelines and the Framework for Safe Drinking Water aim to establish health-based targets and ensure effective water safety plans.

Lead pollution

Air pollution, encompassing both indoor and outdoor sources, is the leading cause of pollution-related fatalities worldwide. In 2021, it was responsible for approximately 8.1 million deaths globally, with over 90% of these deaths occurring in low- and middle-income countries. The burning of fossil fuels, biomass, and household air pollution from cooking with polluting fuels are significant contributors to this issue.

Among the various types of pollution, lead pollution stands out as a significant concern, causing an estimated 900,000 premature deaths in 2019, according to The Lancet Planetary Health. Lead is a toxic metal that can be found in the Earth's crust, and its widespread use has led to extensive environmental contamination, human exposure, and adverse health outcomes. Lead exposure is estimated to cause more than 1.5 million deaths worldwide annually, primarily due to its harmful effects on the cardiovascular system. It is also associated with increased risks of intellectual disability, kidney disease, and other health issues.

Inhalation of lead particles from burning materials and ingestion of contaminated dust, soil, water, or food are common pathways for lead exposure. Young children are particularly vulnerable to lead poisoning due to their developing bodies and age-appropriate behaviours, such as hand-to-mouth activities. UNICEF estimates that one in three children globally have blood lead levels above the recommended limit, putting them at risk of impaired brain development and long-term health issues.

To address lead pollution and its health impacts, the World Health Organization (WHO) and other entities have taken several measures. WHO has published guidelines for clinical management and recommended identifying and eliminating lead exposure sources, especially for vulnerable groups like children and women of reproductive age. Additionally, the Global Alliance to Eliminate Lead Paint, led by WHO and UNEP, aims to encourage countries to implement legally binding laws restricting lead usage in paint.

Chemical pollution

The Lancet Commission on pollution and health reported that pollution was responsible for 9 million premature deaths in 2015, making it the world's largest environmental risk factor for premature death. This number has remained consistent, with pollution causing around 9 million deaths per year since 2015. More recent data from 2021 puts the number of pollution-related deaths at 8.1 million.

While deaths from traditional sources of pollution, such as poor sanitation and wood-burning stoves, are declining, modern forms of pollution, including chemical contaminants, are on the rise. Chemical pollution is an unintended consequence of industrialization, uncontrolled urbanization, population growth, and the combustion of fossil fuels. The absence of adequate national and international chemical policies has allowed this problem to persist and grow.

Air pollution, which accounts for the majority of pollution-related deaths, is closely linked to the combustion of fossil fuels and the release of greenhouse gases. Chemical plants, solvents like paints and cleaning products, and volatile organic compounds (VOCs) in personal care products are significant sources of air pollution. These chemicals can cause a range of health issues, including respiratory and cardiovascular diseases, stroke, and certain cancers.

Water pollution is another contributor to chemical pollution fatalities. Lead, in particular, is a significant concern, causing 900,000 premature deaths, according to a 2019 report. Other toxic chemicals, such as mercury, copper, plastics, pharmaceutical waste, and hormone-disrupting chemicals, are also present in water bodies and contribute to the overall chemical pollution burden.

The impact of chemical pollution is disproportionately felt in low- and middle-income countries, which suffer from the highest exposures to pollutants. More than 90% of pollution-related deaths occur in these regions.

To address the problem of chemical pollution, a multifaceted approach is necessary. This includes reducing the use of volatile organic compounds in personal care products and solvents, setting emission limits for the chemicals industry, transitioning to clean and renewable energy sources, and implementing policies to support sustainable land use, cleaner household energy, and better waste management.

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