Air Pollution's Impact: Human Systems Under Threat

Air pollution is a serious issue that affects human health in a variety of ways. It is caused by vehicle exhaust, smoke, road dust, industrial emissions, pollen, and the chemicals we use in our homes, among other sources. Both short-term and long-term exposure to air pollution can lead to a range of health issues, including coughing, itchy eyes, and respiratory and lung diseases, and can worsen pre-existing conditions such as asthma, cardiovascular disease, and lung cancer. It can also increase the risk of respiratory infections, heart disease, stroke, and premature death. Certain groups are more vulnerable to the effects of air pollution, including children, the elderly, pregnant women, and individuals with pre-existing health conditions.

Respiratory health

Air pollution can have detrimental effects on respiratory health, causing and exacerbating a range of respiratory conditions. The respiratory system is remarkably resilient to air pollution, but constant exposure to high levels of particle pollution will contribute to reduced respiratory function over time.

Respiratory Conditions

Air pollution can cause a range of respiratory conditions, including:

• Coughing
• Wheezing
• Itchy eyes
• Lung diseases, such as asthma, chronic bronchitis, emphysema, and chronic obstructive pulmonary disease (COPD)
• Respiratory infections
• Lung cancer
• Decreased lung function growth in children
• Chronic loss of pulmonary function in adults
• Premature mortality in people with chronic lung disease

Risk Factors

Certain groups of people are more vulnerable to the respiratory effects of air pollution, including:

• Infants and young children: Children are more at risk than adults because their lungs are still developing, and they breathe faster, taking in more polluted air. Being exposed to pollution at a young age increases the risk of developing asthma and COPD later in life.
• Older people: Older individuals, particularly those with long-term lung conditions or heart disease, are more susceptible to the respiratory effects of air pollution.
• People with pre-existing respiratory conditions: Those with asthma, COPD, or other respiratory diseases are at greater risk of adverse respiratory effects from air pollution.
• People who smoke: Smoking can increase the vulnerability to the respiratory effects of air pollution.
• People living in poverty: Low-income communities and minority populations are disproportionately exposed to air pollution and are more vulnerable to adverse health impacts.

Protecting Respiratory Health

To protect respiratory health from air pollution, individuals can take measures such as:

• Reducing time spent outdoors when air pollution levels are high
• Wearing masks when necessary
• Improving indoor air quality by using clean fuels, improving stoves, and using air cleaners
• Quitting smoking
• Consuming a nutritious diet rich in fruits and vegetables

Cardiovascular health

Air pollution is a complex mixture of gases, liquids, and particulate matter. It is the single largest environmental health risk in Europe and a major cause of premature death and disease. Fine particulate matter (PM2.5) is the air pollutant driving the most significant health problems and premature mortality.

Both short- and long-term exposure to air pollution can lead to a wide range of cardiovascular issues. The World Health Organization (WHO) provides evidence of links between exposure to air pollution and an increased risk of heart disease.

Air pollution can cause the following cardiovascular issues:

• Atherosclerosis: Long-term exposure to air pollution can lead to a buildup of plaque in the coronary artery, which can affect heart health.
• Blood vessel ageing: Long-term exposure to particulate matter and nitrogen oxides can prematurely age blood vessels and contribute to a more rapid buildup of calcium in the coronary artery.
• Increased risk of cardiovascular events: The buildup of calcium in the coronary artery can restrict blood flow to the heart and other major blood vessels, increasing the likelihood of cardiovascular events like heart attack and stroke.
• Enhanced coagulation and thrombosis: Air pollution has been linked to enhanced coagulation and thrombosis, which can increase the risk of blood clots and other cardiovascular issues.
• Arrhythmias: Air pollution can increase the risk of arrhythmias, or irregular heartbeats, which can be life-threatening.
• Acute arterial vasoconstriction: Exposure to air pollution has been associated with acute arterial vasoconstriction, or the narrowing of blood vessels, which can reduce blood flow and increase blood pressure.
• Systemic inflammatory responses: Air pollution can trigger systemic inflammatory responses in the body, which can have negative effects on cardiovascular health.

Populations at Risk

Certain populations are at higher risk of experiencing cardiovascular issues due to air pollution:

• Elderly individuals: Older adults may be more susceptible to the effects of air pollution on cardiovascular health.
• Individuals with pre-existing cardiovascular disease: Those with existing heart disease or risk factors such as high blood pressure, high cholesterol, or a smoking habit are more vulnerable to the cardiovascular effects of air pollution.
• Individuals with lower socioeconomic status: Low-income communities and minority populations are disproportionately exposed to air pollution and are more vulnerable to adverse health impacts.

Protecting Cardiovascular Health

To protect cardiovascular health, it is important to reduce exposure to air pollution. This can include:

• Monitoring air quality and avoiding spending prolonged periods outdoors when pollution levels are high.
• Reducing emissions from vehicles, industrial sources, and other contributors to air pollution.
• Encouraging policy changes and regulations to improve air quality and protect cardiovascular health.
• Promoting public education and awareness about the effects of air pollution on cardiovascular health.

In summary, air pollution has significant impacts on cardiovascular health, and it is important to address this issue through individual, community, and policy-level actions to protect the health and well-being of vulnerable populations.

Mental health

Air pollution is a significant environmental health risk, causing a wide range of diseases and contributing to premature death. While the impact of air pollution on physical health is well-established, recent studies have also found a link between air pollution and mental health.

Research suggests that air pollution is associated with higher levels of psychological distress, including anxiety and depression. A study by Dr Melinda Power at George Washington University found that those exposed to higher levels of fine particulate matter, a type of air pollution from cars and factories, experienced higher anxiety levels. Similarly, a University of Washington study found that people living in areas with high air pollution reported higher levels of psychological distress, with the risk of distress increasing alongside the amount of fine particulate matter in the air.

The impact of air pollution on mental health is not limited to adults. A major study in Sweden found that even small increases in air pollution were associated with a significant increase in treated psychiatric problems in children and adolescents. This is particularly concerning as children are more vulnerable to the effects of air pollution, with their developing bodies and organs being more susceptible to damage.

While the exact mechanisms are still being investigated, one theory suggests that air pollution causes inflammation in the brain, which has been associated with depression and cognitive impairments. Animal studies have supported this idea, with mice exposed to high levels of air pollution exhibiting depressive symptoms and behavioural despair.

Overall, the growing body of research highlights the need to address air pollution as a public health emergency. By reducing air pollution, we may be able to mitigate its mental health impacts and improve the overall well-being of individuals, especially those living in highly polluted areas.

Children's health

Children are especially vulnerable to the effects of air pollution. Their bodies, organs, and immune systems are still developing, and they breathe more rapidly than adults, taking in more polluted air relative to their size. Their airways are smaller and still developing, and they are more susceptible to infection as their bodies' defences are not yet fully formed.

Children are also more likely to be active outdoors, increasing their exposure to air pollution. They are also often closer to the ground, where some pollutants reach peak concentrations. This means that children are at a greater risk of lung disease as they age, and their lung function can be damaged even at lower levels of exposure. Air pollution has been linked to lower cognitive test outcomes and negative mental and motor development. It can also trigger asthma and childhood cancer.

In 2016, the World Health Organization (WHO) estimated that 600,000 children died from acute lower respiratory infections caused by polluted air. Globally, 93% of children under 15 years of age are exposed to fine particulate matter (PM2.5) levels above WHO air quality guidelines. In low- and middle-income countries, this figure rises to 98% of all children under five. Air pollution is a leading threat to child health, accounting for almost one in ten deaths in children under five.

Children who are exposed to high levels of air pollution may be at greater risk for chronic diseases such as cardiovascular disease later in life. Air pollution damages health during childhood and increases the risk of diseases in adulthood. It is a serious issue that needs to be addressed to protect children's health and ensure their future well-being.

Pregnancy

Air pollution can have a detrimental impact on pregnancy, affecting both the health of the pregnant person and the development of the baby. Pollutants can cross the placenta, impacting the placenta's health and disrupting the baby's growth.

Risk Factors

Several factors influence the specific effects of air pollution on pregnancy:

• The stage of the baby's development when exposed to the pollutant.
• The duration of exposure and the level of pollution.
• The specific type of pollutant.
• Other factors, such as exposure to racism, lack of access to quality food, inadequate prenatal care, or unsafe housing, may exacerbate the effects of air pollution.

Potential Effects of Air Pollution on Pregnancy

Preterm Birth and Pregnancy Loss

Air pollution has been linked to an increased risk of preterm birth and pregnancy loss. A 2019 study found a correlation between exposure to common pollutants like ozone, sulfur dioxide, nitrogen oxide, and nitrogen dioxide, and preterm labour, with the risk being highest during subsequent pregnancies.

Low Birth Weight

Air pollution, particularly high levels of certain pollutants like nitrogen dioxide, has been associated with low birth weight. A 2013 analysis of 14 population-level studies supported this connection. Low birth weight is a risk factor for developmental delays, health issues, and death after birth.

Stillbirth

Exposure to air pollution, especially during the third trimester, has been correlated with an increased risk of stillbirth, which refers to the death of the baby late in pregnancy (after 20 weeks).

Disrupted Development and Small Size

Air pollution can disrupt a baby's development, resulting in them being born unusually small. It can also cause preterm delivery, leading to very small babies with underdeveloped bodies and lungs.

Lung Development Issues

Air pollution may affect lung development, either directly or indirectly through preterm birth. This can have long-term respiratory implications, such as asthma and allergies.

Health Concerns for the Parent

Exposure to air pollution during pregnancy is associated with an increased risk of pregnancy-related complications for the parent, including preeclampsia and high blood pressure, which can necessitate early delivery.

Protecting Pregnant People from Air Pollution

While individuals often have limited control over the levels of pollution around their homes or workplaces, there are some strategies to reduce the harmful effects of polluted air:

• Evacuating to a safer area during periods of extremely dangerous air quality, such as during a wildfire.
• Avoiding cooking during wildfire season to prevent worsening indoor air pollution.
• Installing a carbon monoxide detector and taking measures to reduce asbestos and mold exposure.
• Wearing a face covering when using cleaning products or paint, and avoiding smoking indoors.
• Using high-efficiency particulate air filters to improve indoor air quality.
• Staying indoors, wearing face coverings when outdoors, and using quality air filters during periods of high air pollution.

Pregnant individuals who live in polluted areas or are exposed to indoor air pollution, such as cigarette smoke, are at a higher risk of negative pregnancy outcomes. It is crucial for those concerned about air pollution to consult with healthcare professionals for guidance and support.

Frequently asked questions