Outdoor Air Pollution

What Is Air Pollution and How Does It Affect Health?

The term air pollution refers to harmful particles or gases present in the atmosphere that can be inhaled. This polluted air is often a mixture of particulate matter, ozone, nitrogen oxides, volatile organic compounds (VOCs), and carbon monoxide. The composition of air pollution varies by location, season, and pollution sources in the area.

Sources of Air Pollution

Air pollution arises from both human activity and natural processes:

• Human-made sources include the burning of fossil fuels in vehicles (cars, trucks, airplanes), industrial emissions, power plants, and household heating and cooking.

• Natural sources include volcanic eruptions, wildfires, and dust storms, particularly in dry, desert regions.

How Air Pollution Impacts Health

Exposure to air pollution affects virtually everyone, from unborn babies to the elderly. The lungs are the first organ exposed, and they often suffer the earliest damage. Studies show that this damage is due to oxidative stress and inflammation caused by pollutants.

Importantly, air pollution doesn’t just harm the lungs. It also negatively affects the heart and circulatory system, increasing the risk of heart attacks, respiratory diseases, and in the long term, even lung cancer.

Individual responses to air pollution differ based on factors like:

• Age and lung development

• Existing health conditions (e.g., asthma, COPD)

• Lung capacity

• Physical activity levels

• Time spent outdoors or in polluted environments

Types of Pollutants and Measurements

Pollution contains various harmful substances, and their combined effect causes health issues. A single pollutant isn’t responsible; it’s the interaction between multiple pollutants that leads to disease.

Pollutants are often measured by mass per volume of air, typically in micrograms per cubic meter (μg/m³). Particulate matter (PM) is a key component, and its impact is measured by size:

• PM10: particles up to 10 micrometres

• PM2.5: finer particles, more harmful due to deeper penetration into lungs

Short-Term Health Effects of Air Pollution

Air pollution is linked with immediate health issues, especially in people with pre-existing lung or heart conditions.

• Asthma attacks

• COPD flare-ups

• Wheezing, coughing, and breathlessness

• Reduced lung function

• Increased need for medications

Medical studies report more emergency visits, doctor consultations, and hospital admissions on days with high pollution levels. There is also a noticeable spike in heart attacks and even mortality on such days.

Long-Term Health Effects: From Asthma to Lung Cancer

Chronic exposure to air pollution can lead to serious, long-term health conditions. For both adults and children, prolonged inhalation of pollutants is associated with:

• Asthma

• Chronic bronchitis

• Cardiovascular disease

• Premature death

• Lung cancer

Impact on Children

Children are particularly vulnerable because:

• They spend more time outdoors

• They breathe more rapidly than adults

• Their lungs and immune systems are still developing

Long-term effects on children include:

• Persistent cough

• Acute bronchitis

• Reduced lung development

• Increased risk of asthma

Impact on Adults

Adults exposed to long-term pollution may experience:

• Chronic cough and phlegm

• Wheezing and breathlessness

• Accelerated lung function decline

• Greater risk of respiratory illnesses and lung cancer