Air Pollution: A Silent Health Crisis

Air pollution is a major threat to health and climate across the globe. It is the presence of 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, but air pollutants can also enter the bloodstream. This can lead to inflammation, oxidative stress, immunosuppression, and mutagenicity in cells throughout the body, impacting the lungs, heart, and brain, among other organs. Air pollution is a risk factor for all-cause mortality as well as specific diseases, including stroke, heart disease, lung cancer, and respiratory infections. It is also linked to adverse pregnancy outcomes and can affect children before they are born.

Air pollution increases the risk of respiratory infections, heart disease, stroke and lung cancer

Air pollution is a major threat to health across the globe. It is defined by the presence of contaminants in the atmosphere, such as dust, fumes, gas, mist, odour, smoke or vapour, in quantities that can be harmful to human health. These pollutants are inhaled through the respiratory tract, and can enter the bloodstream, travelling to organs like the lungs, heart and brain, and causing disease.

Respiratory Infections

Air pollution can cause respiratory infections, with infectious diseases, asthma, allergic rhinitis, and chronic obstructive pulmonary disease (COPD) all being significantly aggravated by air pollution. In those with COPD, exposure to air pollution may cause acute episodes requiring hospitalisation. Air pollution can also worsen asthmatic symptoms.

Heart Disease

Air pollution is a contributing factor to heart disease, with a large body of evidence showing that it can exacerbate existing cardiovascular disease and contribute to the development of the disease. Fine particulate matter (PM2.5) in particular has been found to increase the risk of cardiovascular events, with exposure over a few hours to weeks triggering heart attacks and death. Longer-term exposure can lead to an increased risk of cardiovascular mortality and decreased life expectancy.

Stroke

Both short- and long-term exposure to air pollution increases the risk of stroke. A meta-analysis of 28 countries worldwide found that gaseous and particulate matter air pollutants had a temporal association with hospital admissions and mortality due to stroke. The pollutants with the strongest associations were PM2.5, NO2, SO2 and CO.

Lung Cancer

Air pollution has been linked to lung cancer, with particles found in vehicle exhaust and smoke from fossil fuels associated with non-small cell lung cancer (NSCLC). A study of people living in England, South Korea and Taiwan found that exposure to increasing concentrations of airborne particulate matter was linked to an increased risk of NSCLC.

Overall, air pollution poses a significant risk to human health, contributing to respiratory infections, heart disease, stroke and lung cancer.

Pollutants can enter the bloodstream, impacting the lungs, heart and brain

Air pollution is a major threat to health across the globe. Breathing in air pollutants leads to inflammation, oxidative stress, immunosuppression, and mutagenicity in cells throughout the body, impacting the lungs, heart, brain, and other organs, ultimately leading to disease.

Due to their small size, some air pollutants can enter the bloodstream via the lungs and circulate throughout the entire body, leading to systemic inflammation and carcinogenicity. Fine particulate matter, such as PM2.5, is of particular concern as these very small particles can penetrate deep into the lungs and enter the bloodstream.

Impact on the Lungs

When pollutants are deposited in the respiratory tract in sufficient amounts, they can induce inflammation of the airways and lungs. This can cause a range of respiratory symptoms, including cough, phlegm, wheezing, and decreased lung function. Constant exposure to elevated particle pollution will contribute to reduced respiratory function, even in apparently healthy people.

Impact on the Heart

Particle pollution, or particulate matter (PM), is made up of tiny pieces of solids or liquids in the air. Research shows that both short- and long-term exposure to particulate pollution are linked to an increased risk of heart attacks and other forms of heart disease. Small particles are the biggest problem as they can be inhaled deeply into the lungs, where they can then affect the heart and blood vessels.

Impact on the Brain

An emerging body of evidence suggests that inhaled pollutants can have harmful effects on the central nervous system. Traffic-related air pollution (TRAP) exposure has been associated with adverse effects on cognitive development in children and cognitive decline and dementia in the elderly. Studies have shown that TRAP exposure may lead to functional brain changes, including lower functional connectivity between certain brain regions and delayed brain maturation.

In summary, air pollution can have significant impacts on the lungs, heart, and brain, leading to a range of health issues and an increased risk of disease.

Fine particulate matter can penetrate deep into the lungs, enter the bloodstream and travel to organs

Fine particulate matter, such as PM2.5, is a dangerous air pollutant that can have significant impacts on human health. These particles are so small that they can be inhaled and penetrate deep into the lungs, causing a range of issues, including irritation and inflammation, as well as damaging the lining of the respiratory tract. Not only do these particles cause issues in the lungs, but they can also enter the bloodstream and travel to other organs in the body, leading to systemic damage.

The health effects of fine particulate matter are wide-ranging and can be both short- and long-term. Short-term exposure to these particles can aggravate lung diseases, trigger asthma attacks, and increase the risk of respiratory infections. It has also been linked to heart attacks and abnormal heartbeats. Over time, prolonged exposure to fine particulate matter increases the chances of developing chronic lung diseases, cardiovascular disease, and lung cancer.

The World Health Organization (WHO) has set guidelines for the maximum safe level of PM2.5, demonstrating the seriousness of the health risks associated with this pollutant. In 2021, the WHO published new air quality guidelines following a systematic review of the latest scientific evidence on the detrimental effects of air pollution on human health.

Fine particulate matter is a major concern for public health, especially in urban areas where air pollution levels tend to be higher. It is important to take steps to reduce exposure to these pollutants, such as limiting time spent near busy roadways and avoiding indoor activities that contribute to poor air quality, like smoking or using wood-burning fireplaces.

Children, the elderly, and those with pre-existing health conditions are especially vulnerable to the health impacts of fine particulate matter. Additionally, low-income communities and minority populations are often disproportionately exposed to air pollution and are more susceptible to adverse health outcomes. It is crucial to address these disparities and work towards environmental justice to protect the health of vulnerable populations.

Air pollution is a particular risk for children, the elderly and pregnant women

Children are especially vulnerable to air pollution due to their developing lungs and brains. Their immune systems are weaker than those of adults, making them more susceptible to infections and viruses. Young children also breathe faster than adults, taking in more air relative to their body weight, and often breathe through their mouths, which increases the number of pollutants they inhale. Air pollution has been linked to respiratory conditions such as pneumonia, bronchitis and asthma in children, and can cause irreversible, immediate and long-term health effects.

For pregnant women, air pollution can cause serious health issues for the foetus. The woman's body can store harmful chemicals from the air, which are then passed to the baby during pregnancy and breastfeeding. Air pollution has been linked to negative pregnancy outcomes, such as miscarriages, low birth weight and preterm birth. It can also impact the healthy development of children's brains.

The elderly are also at risk from air pollution. As people age, their bodies are less able to compensate for the effects of environmental hazards. Air pollution can aggravate health issues such as heart disease, lung diseases, stroke, asthma and diabetes. Fine particle pollution has been linked to premature death, cardiac arrhythmias, heart attacks, asthma attacks and the development of chronic bronchitis in older people.

Indoor air pollution can be more harmful than outdoor air pollution

Air pollution is the presence of one or more contaminants in the atmosphere, such as dust, fumes, gas, mist, odour, smoke or vapour. These pollutants can enter our bloodstream and contribute to coughing or itchy eyes and cause or worsen many breathing and lung diseases, leading to hospitalizations, cancer, or even premature death. Almost every organ in the body can be impacted by air pollution.

While we may associate air pollution with the outdoors, the air inside homes, offices, and other buildings can be more polluted than the air outside. On average, people spend approximately 90% of their time indoors, where the concentrations of some pollutants are often two to five times higher than outdoor concentrations. In some cases, indoor pollution levels can exceed 100 times that of outdoor levels of the same pollutants.

Common indoor air pollutants include radon, smoke, and lead dust. Carbon monoxide from a faulty furnace, mould from damp walls, or volatile organic compounds from a newly painted room also contaminate indoor air. Pollutants such as fine particles from candles or fireplaces (or from outdoors) can also affect our health. Biological pollutants, such as mould, pollen, animal dander, dust mites, and cockroaches, may trigger breathing problems, allergic symptoms, or asthma attacks. Tobacco smoke contains about 200 known poisons, such as formaldehyde and carbon monoxide, and at least 60 chemicals known to cause cancer.

The health effects of indoor air pollution can be immediate or show up years later. Immediate effects include irritation of the eyes, nose and throat, headaches, dizziness, and fatigue. Other health effects that may show up years after exposure or only after long or repeated periods of exposure include respiratory diseases, heart disease, and cancer.

• Ensure adequate ventilation when using chemicals for crafts, decorating, or cleaning.
• Change air filters in your home regularly.
• Install radon detectors in every room and regularly check them to ensure they are working.
• Don't smoke indoors.

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