Air Pollution: A Global Killer?

Air pollution is a serious global issue with far-reaching health implications. According to recent reports, air pollution is responsible for a staggering number of deaths worldwide, with estimates ranging from 6.5 million to 9 million annually. In 2021, it was reported that air pollution caused 8.1 million deaths globally, making it the second leading risk factor for death, including for children under five years old. The impact of air pollution is not limited to mortality, as it also contributes to debilitating chronic diseases and impacts vulnerable populations disproportionately. The major sources of outdoor pollution include residential energy use, vehicles, power generation, agriculture, and industry. Indoor air pollution, caused by household combustion devices, is also a significant concern, with an estimated 500,000 child deaths linked to household air pollution. As the world continues to grapple with the effects of climate change, addressing air pollution becomes increasingly crucial to protect public health and reduce its societal and economic burden.

Fossil fuel combustion

The health effects of fossil fuel combustion are far-reaching and affect people of all ages. Research has shown that exposure to particulate matter from fossil fuels can lead to acute changes in heart rate and HRV, as well as chronic changes in atherosclerotic plaques and markers of inflammation. The evidence suggests that particles from fossil fuel combustion sources, such as coal and traffic, are among the most toxic to human health. The adverse health effects include non-respiratory diseases, such as cardiovascular disease, and respiratory illnesses, which can be especially harmful to children.

In 2018, more than 8 million people died from fossil fuel pollution, according to research by Harvard University and other institutions. This number is significantly higher than previously estimated, highlighting the detrimental impact of fossil fuels on global health. The transition from fossil fuels to renewable energy sources is crucial not only for mitigating climate change but also for improving public health and reducing the number of premature deaths attributed to air pollution.

The impact of fossil fuel combustion on children's health is particularly concerning. Poor and vulnerable communities bear a disproportionate burden of disease and developmental impairment due to exposure to air toxics and climate change caused by the combustion of fossil fuels. Fossil fuel emissions impair children's health, ability to learn, and potential to contribute to society, making them less resilient and their communities less equitable. Therefore, addressing fossil fuel combustion and transitioning to alternative energy sources are crucial steps in protecting public health, especially for future generations.

Outdoor air pollution

In 2021, air pollution was responsible for 8.1 million deaths globally, according to the State of Global Air report. It has become the second-leading risk factor for death, ahead of tobacco and poor diet, including for children under five years old. The report also found that exposure to air pollution was linked to over 700,000 deaths of children under five, with 500,000 child deaths attributed to household air pollution due to cooking with polluting fuels, mostly in Africa and Asia.

Particulate matter (PM) is a common proxy indicator for air pollution, and there is strong evidence of its negative health impacts. The major components of PM are sulfates, nitrates, ammonia, sodium chloride, black carbon, mineral dust, and water. Other pollutants of major health concern include carbon monoxide, ozone, nitrogen dioxide, and sulfur dioxide.

Addressing air pollution is key to protecting public health. Policies and investments supporting cleaner transport, energy-efficient homes, power generation, industry, and better municipal waste management can effectively reduce key sources of outdoor air pollution. Access to clean household energy solutions for cooking, heating, and lighting is also crucial.

Indoor air pollution

According to the State of Global Air 2024 report, air pollution caused 8.1 million deaths worldwide in 2021, making it the second-leading risk factor for death. This figure includes deaths attributed to indoor air pollution, which is caused by the burning of polluting fuels such as wood, animal dung, charcoal, agricultural waste, and kerosene in open fires or inefficient stoves for cooking, heating, and lighting.

The health impacts of indoor air pollution are far-reaching and severe. The incomplete combustion of solid fuels and kerosene used for cooking releases particulate matter and other pollutants, which have detrimental effects on the body. These pollutants irritate the airways and lungs, impair the immune system, and reduce the blood's oxygen-carrying capacity. Women and children, typically responsible for household chores such as cooking and collecting firewood, bear the brunt of the health consequences from the use of polluting fuels and technologies in homes.

The diseases caused by exposure to indoor air pollution include pneumonia in children and chronic obstructive pulmonary disease, lung cancer, stroke, and cardiovascular disease in adults. Among the 3.2 million deaths attributed to indoor air pollution, 32% are due to ischaemic heart disease, 21% to lower respiratory infections, 23% to stroke, 19% to chronic obstructive pulmonary disease, and 6% to lung cancer. Furthermore, indoor air pollution is linked to low birth weight, tuberculosis, cataracts, and nasopharyngeal and laryngeal cancers.

To address the health risks posed by indoor air pollution, significant policy changes are necessary to increase access to clean fuels and technologies, such as solar, electricity, biogas, liquefied petroleum gas, and improved biomass stoves that meet emission targets. These interventions can reduce household air pollution, protect public health, and contribute to climate change mitigation.

Ozone

Air pollution is the leading environmental threat to public health worldwide. In 2021, it was responsible for 8.1 million deaths globally, with millions more suffering from debilitating chronic illnesses. This figure represents around 1 in 8 deaths, with nearly 90% of these deaths attributed to noncommunicable diseases.

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 alone. The proportion of the population experiencing high ozone exposures is increasing worldwide, and countries in the Middle East, South Asia, and East Asia have the highest average ozone exposure levels. As climate change continues to warm the planet, areas with high levels of NO2 can expect to see even higher levels of ozone, leading to greater health impacts.

Health impacts

Air pollution is the presence of one or more contaminants in the atmosphere, such as dust, fumes, gas, mist, odour, smoke or vapour, in quantities and durations that can be harmful to human health. In 2021, air pollution was responsible for 8.1 million deaths worldwide, becoming the second leading risk factor for death, including for children under five years old.

The health impacts of air pollution are far-reaching and affect nearly every person on Earth. Short-term exposure to air pollutants is closely related to COPD (Chronic Obstructive Pulmonary Disease), cough, shortness of breath, wheezing, asthma, respiratory disease, and high rates of hospitalization. Long-term exposure to air pollution is associated with chronic asthma, pulmonary insufficiency, cardiovascular diseases, and cardiovascular mortality.

The main pathway of exposure from air pollution is through the respiratory tract. When inhaled, air pollution can cause inflammation, oxidative stress, immunosuppression, and mutagenicity in cells throughout the body, impacting the lungs, heart, brain, and other organs, ultimately leading to disease. Fine particulate matter, such as PM2.5, is of particular concern as these very small particles can penetrate deep into the lungs, enter the bloodstream, and travel to organs, causing systemic damage to tissues and cells.

The health impacts of air pollution can lead to non-communicable diseases (NCDs) such as stroke, heart disease, and lung cancer. In 2021, long-term exposure to ozone, an air pollutant and greenhouse gas, contributed to an estimated 489,000 deaths globally, with significant impacts in low- and middle-income countries.

Certain populations are more vulnerable to the health impacts of air pollution, including children, the elderly, and pregnant women. Maternal exposure to air pollution is associated with adverse birth outcomes, such as low birth weight, pre-term birth, and small for gestational age births. Additionally, air pollution may affect diabetes and neurological development in children.

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