Air Pollution: The Silent Health Crisis

Air pollution is a major threat to global health, causing more than 6.5 million deaths each year. It is caused by a mix of hazardous substances from both human-made and natural sources, including vehicle emissions, fuel oils, natural gases, manufacturing by-products, and fumes from chemical production. The main pathway of exposure is through the respiratory tract, leading to inflammation, oxidative stress, immunosuppression, and mutagenicity in cells throughout the body. This can impact almost every organ, including the lungs, heart, and brain, ultimately leading to disease and premature death. Research has linked air pollution to an increased risk of lung cancer, heart disease, respiratory infections, asthma, and other adverse health outcomes, especially in vulnerable populations such as children, pregnant women, and the elderly.

Air pollution causes respiratory issues, including asthma, bronchitis, and emphysema

Air pollution is a major threat to global health, causing more than 6.5 million deaths each year. It is caused by a mix of hazardous substances from both human-made and natural sources. Human-made sources include vehicle emissions, fuel oils, natural gases, manufacturing by-products, and power generation. Natural sources include smoke from wildfires, ash and gases from volcanic eruptions, and methane from decomposing organic matter in soils.

The primary pathway of exposure to air pollution is through the respiratory tract. Pollutants such as ozone, nitrogen dioxide, and fine particulate matter can cause inflammation, oxidative stress, immunosuppression, and mutagenicity in cells throughout the body, impacting the lungs, heart, and brain, among other organs.

One of the most well-established impacts of air pollution is its effect on respiratory health. Air pollution is linked to an increased risk of developing respiratory diseases, including asthma, bronchitis, and emphysema. Children who live in communities with high levels of air pollution, particularly those living near busy roads, are more likely to develop asthma. Higher air pollution levels also increase short-term respiratory infections, leading to more school absences.

In addition to asthma, air pollution is a significant risk factor for bronchitis. A large study of 50,000 women found that long-term exposure to fine particulate matter and nitrogen dioxide was associated with an increased risk of chronic bronchitis. Children exposed to high levels of air pollutants are also more likely to develop bronchitis symptoms in adulthood.

Emphysema, another respiratory disease, has also been linked to air pollution. Air pollution can worsen existing emphysema and make it harder for individuals to breathe. Overall, air pollution has a significant impact on respiratory health, and reducing air pollution is crucial to improving public health.

It increases the risk of lung cancer and other cancers

Air pollution is a mix of hazardous substances from both human-made and natural sources. It is a major threat to global health, causing more than 6.5 million deaths each year worldwide. The main pathway of exposure from air pollution is through the respiratory tract. Breathing in these pollutants leads to inflammation, oxidative stress, immunosuppression, and mutagenicity in cells throughout the body, impacting the lungs, heart, and brain, among other organs.

One of the most well-established links between air pollution and cancer is with lung cancer. Overwhelming evidence shows that particle pollution in the outdoor air we breathe—from sources like vehicle exhaust, coal-fired power plants, and other industrial sources—can cause lung cancer. Particle pollution increases the risk of dying early, heart disease, and asthma attacks, and it can also interfere with the growth and function of the lungs. Fine particles can enter deep into the lungs and are linked to lung cancer, even increasing the mortality risk by 36% per 10 µg/m3 increased exposure to PM2.5. Smaller particles are more dangerous as they get trapped deep in the lungs and can even enter the bloodstream, causing damage to our health.

In addition to lung cancer, air pollution has been linked to an increased risk of mortality for several other types of cancer, including breast, liver, and pancreatic cancer. A long-term study found an association between lung cancer incidence and increased reliance on coal for energy generation. Using a national dataset of older adults, researchers found that 10-year long exposures to PM2.5 and NO2 increased the risks of colorectal and prostate cancers. Occupational exposure to benzene, a component of gasoline, can cause leukemia and is associated with non-Hodgkin’s Lymphoma.

Reducing air pollution is crucial for mitigating the risk of developing lung cancer and other cancers. Actions such as increasing green spaces, transitioning to cleaner energy sources, and promoting active transportation (walking and cycling) not only reduce air pollution but also provide a range of health benefits, including a healthier diet, increased physical activity, and lower rates of non-communicable diseases.

It can cause heart disease and increase the risk of heart attacks

Air pollution is a mix of hazardous substances from both human-made and natural sources. It is a major threat to global health, causing more than 6.5 million deaths each year worldwide. It is the presence of one or more contaminants in the atmosphere, such as dust, fumes, gas, mist, odour, smoke or vapour, in quantities that can be harmful to human health.

The main pathway of exposure from air pollution is through the respiratory tract. Breathing in these pollutants leads to inflammation, oxidative stress, immunosuppression, and mutagenicity in cells throughout our body, impacting the lungs, heart, brain and other organs. Almost every organ in the body can be impacted by air pollution. Some pollutants are so small that they can penetrate into the bloodstream via the lungs and circulate throughout the entire body, leading to systemic inflammation and carcinogenicity.

Air pollution is a risk factor for all-cause mortality as well as specific diseases. It has been linked to heart disease and an increased risk of heart attacks. Research has shown that air pollution can exacerbate existing heart disease and contribute to the development of the disease. The evidence is particularly strong for outdoor particle pollution exposure. Fine particulate matter (particulate matter with diameters less than 2.5 µm or PM2.5) can increase the risk of cardiovascular events.

PM2.5 can trigger heart attacks and death in those with heart disease. Longer-term exposure can lead to an increased risk of cardiovascular mortality and decreased life expectancy. For the individual, the risk of cardiovascular disease from particle pollution is smaller than the risk from many other well-established risk factors. However, for the population as a whole, short- and long-term exposure has been shown to increase hospitalisations for serious cardiovascular events.

The Multi-Ethnic Study of Atherosclerosis Air Pollution Study (MESA Air) provides evidence that long-term exposure to air pollution is a cardiovascular disease risk factor. The study found a direct link between air pollution exposure and plaque buildup in healthy individuals over the long term. This accelerated atherosclerosis, to the extent that some participants' risk of a heart attack increased. The higher the exposure level, the faster the atherosclerosis progressed. This buildup of calcium can restrict blood flow to the heart and other major blood vessels, increasing the likelihood of cardiovascular events like heart attacks and strokes.

Air pollution impacts the brain, increasing the risk of cognitive decline

Air pollution is a mix of hazardous substances from both human-made and natural sources. It is a major threat to global health, causing more than 6.5 million deaths each year worldwide. This number has increased over the past two decades. The primary sources of human-made air pollution are vehicle emissions, fuel oils, natural gas, manufacturing by-products, power generation, and chemical production.

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 that can be harmful to human health. The main pathway of exposure is through the respiratory tract. However, some air pollutants are so small that they can penetrate the bloodstream via the lungs and circulate throughout the body, leading to systemic inflammation and carcinogenicity.

Almost every organ in the body can be impacted by air pollution. Research has shown that air pollution increases the risk of lung and heart disease, cancer, respiratory issues, and even premature death. It is also linked to an increased risk of reproductive and developmental harm, including reduced fertility, pregnancy complications, preterm birth, and low birth weight.

One of the organs affected by air pollution is the brain. Exposure to air pollution can lead to brain inflammation, structural changes, and an increased risk of cognitive decline. A study by the National Institute of Environmental Health Sciences found that children living in communities with higher pollution levels had an increased risk of cognitive and emotional problems later in adolescence. This is because air pollutants can alter the size of a child's developing brain. Additionally, a National Toxicology Program (NTP) report linked exposure to air pollution during pregnancy to an increased risk of hypertensive disorders, which are a leading cause of pre-term birth and low birth weight.

It is linked to adverse pregnancy outcomes, including low birth weight and pre-term birth

Air pollution is a mix of hazardous substances from both human-made and natural sources. It is a major threat to global health, causing more than 6.5 million deaths each year worldwide. The primary sources of human-made air pollution include vehicle emissions, fuel oils, natural gas used for heating, manufacturing by-products, coal-fueled power plants, and chemical production fumes.

Natural sources of air pollution include smoke from wildfires, ash and gases from volcanic eruptions, and gases like methane, emitted from decomposing organic matter in soils. Wildfires, in particular, increase air pollution in surrounding areas, affecting regional air quality. The health effects of wildfire smoke can range from eye and respiratory tract irritation to more severe conditions, including reduced lung function, asthma exacerbation, heart failure, and even premature death.

Children, pregnant women, and the elderly are especially vulnerable to smoke exposure. Maternal exposure to air pollution is associated with adverse birth outcomes, including low birth weight, pre-term birth, and small for gestational age births. A growing body of evidence suggests that air pollution may also impact neurological development in children and increase the risk of diabetes.

Additionally, exposure to air pollution during pregnancy can lead to dangerous changes in blood pressure, known as hypertensive disorders, which are a leading cause of pre-term birth, low birth weight, and maternal and fetal illness and death. Research has also shown that living near major roadways may increase a woman's risk of breast cancer.

The impacts of air pollution on pregnancy outcomes highlight the importance of mitigating air pollution and protecting vulnerable populations, especially pregnant women and their developing fetuses.

Frequently asked questions