Air pollution is a global killer – and it’s the under fives who are most at risk

The evidence is absolutely damning: children’s health is being dramatically affected by air-based pollutants that having a devastating impact on the health of the human race – and becoming the second leading global risk factor for death.

What is made abundantly clear in with the publication of the fifth edition of the State of Global Air (SoGA) report is that the under 5s age group is particularly vulnerable to the knock-on effects – among them premature birth, low birth weight and lung diseases.

The report, which has been published by the Health Effects Institute (HEI), an independent U.S.-based nonprofit research organisation, found air pollution accounted for 8.1 million deaths globally in 2021. Beyond these deaths, many more millions of people are living with debilitating chronic diseases, putting tremendous strains on health care systems, economies, and societies.

Produced for the first time in partnership with children’s charity UNICEF, the report finds that children under five years old are especially vulnerable. In 2021, exposure to air pollution was linked to more than 700,000 deaths of children under five years old, making it the second-leading risk factor for death globally for this age group, after malnutrition. No fewer than half a million of 500,000 of these child deaths were linked to household air pollution due to cooking indoors with polluting fuels, mostly in Africa and Asia.

‘Leading global risk factor’

The new SoGA Report offers a detailed analysis of recently released data from the Global Burden of Disease study from 2021 that shows the severe health impacts pollutants like outdoor fine particulate matter (PM_2.5), household air pollution, ozone (O₃), and nitrogen dioxide (NO₂) are having on human health around the world. Data covering over 200 countries and territories is included, and it points to a world in which almost everyone on earth breathes in unhealthy levels of air pollution on a daily basis.

The vast majority of these global air pollution deaths, equating to nearly eight million people, can be blamed on are PM_2.5 air pollution, including from ambient PM_2.5 and household air pollution. Tiny poisonous particles are so small they remain in the lungs and can enter the bloodstream, affecting many organ systems and increasing the risks for noncommunicable diseases in adults like heart disease, stroke, diabetes, lung cancer, and chronic obstructive pulmonary disease (COPD).

The report says that PM_2.5 has been found to be the most consistent and accurate predictor of poor health outcomes around the world.

Dr Elena Craft, President of HEI, said: “We hope our State of Global Air report provides both the information and the inspiration for change. Air pollution has enormous implications for health. We know that improving air quality and global public health is practical and achievable.”

‘Enormous implications for health’

PM_2.5 air pollution comes from the burning of fossil fuels and biomass in sectors such as transportation, residential homes, coal-burning power plants, industrial activities, and wildfires. These emissions not only impact people’s health but also contribute to the greenhouse gases that are warming the planet. The most vulnerable populations are disproportionately affected by both climate hazards and polluted air.

In 2021, long-term exposure to ozone contributed to an estimated 489,518 deaths globally, including 14,000 ozone-related COPD deaths in the United States, higher than other high-income countries. As the world continues to warm from the effects of climate change, areas with high levels of NO₂ can expect to see higher levels of ozone, bringing even greater health effects.

For the first time, this year’s report includes exposure levels and related health effects of nitrogen dioxide (NO₂), including the impact of NO₂ exposures on the development of childhood asthma. Traffic exhaust is a major source of NO₂, which means densely populated urban areas, particularly in high-income countries, often see the highest levels of NO₂ exposures and health impacts.

Dr Pallavi Pant is head of global health at HEI and oversaw the release of the report. “This new report offers a stark reminder of the significant impacts air pollution has on human health, with far too much of the burden borne by young children, older populations, and low- and middle-income countries,” she said.

“This points sharply at an opportunity for cities and countries to consider air quality and air pollution as high-risk factors when developing health policies and other noncommunicable disease prevention and control programs.”

‘Children are uniquely vulnerable’

Some of the greatest health impacts of air pollution are seen in children. Children are uniquely vulnerable to air pollution and the damage from air pollution can start in the womb with health effects that can last a lifetime. For example, children inhale more air per kilogram of body weight and absorb more pollutants relative to adults while their lungs, bodies and brains are still developing.

Exposure to air pollution in young children is linked to pneumonia, responsible for 1 in 5 child deaths globally, and asthma, the most common chronic respiratory disease in older children. The inequities linked to the impact of air pollution on child health are striking. The air pollution-linked death rate in children under the age of five in East, West, Central and Southern Africa is 100 times higher than their counterparts in high income countries.

Kitty van der Heijden, deputy executive director at UNICEF, said that a ‘global emergency was undeniable’.

“Despite progress in maternal and child health, every day almost 2000 children under five years die because of health impacts linked to air pollution. Our inaction is having profound effects on the next generation, with lifelong health and well-being impacts,” said van der Heijden.

“The global urgency is undeniable. It is imperative governments and businesses consider these estimates and locally available data and use it to inform meaningful, child-focused action to reduce air pollution and protect children’s health.”

There are some positives to take however, not least that since 2000, the death rate linked to children under five has dropped by 53 per cent, due largely to efforts aimed at expanding access to clean energy for cooking, as well as improvements in access to healthcare, nutrition, and better awareness about the harms associated with exposure to household air pollution.

Many countries, particularly those experiencing the highest levels of air pollution, are finally tackling the problem head on. Air quality actions in regions like Africa, Latin America, and Asia, such as installing air pollution monitoring networks, implementing stricter air quality policies, or offsetting traffic-related air pollution by moving to hybrid or electric vehicles, are all having measurable impacts on pollution and improving public health.