When air pollutants enter the body, they can affect the:

• Eyes, nose and throat
• Heart and associated blood vessels
• Lungs and respiratory system.

However, research by the International Agency for Research on Cancer suggests that air pollution can damage every organ in our body.

Air pollution can have immediate health effects, causing symptoms that appear within hours or days of exposure. It can also lead to serious long-term impacts that develop over years.

Short-term exposure to air pollution (over a few hours or a day) can cause immediate symptoms such as:

• Coughing and wheezing.
• Shortness of breath.
• Irritation of the eyes, nose, or throat.
• Skin irritation or sensitivity.
• For individuals with pre-existing conditions like asthma, chronic obstructive pulmonary disease (COPD), or hay fever, even brief exposure can trigger flare-ups or worsen symptoms. Children, older adults, and those with underlying respiratory or cardiovascular conditions may be particularly sensitive.

Prolonged exposure to air pollution, whether over years or lifetimes, can lead to the development or worsening of chronic health outcomes, including:

• Respiratory diseases – Chronic Obstructive Pulmonary Disease (COPD), lung cancer, asthma, and decreased lung function.
• Cardiovascular disease – risks of hypertension, heart failure, myocardial infarctions (heart attacks), arrhythmias (abnormal rhythms of the heart) and stroke.
• Diabetes and other metabolic disorders.
• Cognitive decline and neurological disorders – dementia and Parkinson’s disease.
• Adverse reproductive health outcomes – low birth weight, premature birth, developmental issues in children, and infertility.
• Mental health conditions – depression and anxiety.

The extent of harm caused by air pollution depends on several factors:

• The level of exposure (dose and duration) – people can experience exposure to varying concentrations of air pollution, over different periods of time. The longer you are exposed for the larger the effect.
• Environment – where and how an individual comes into contact with the pollutant can influence how it affects you (e.g., whether you’re in a confined space, near traffic, or in an area with limited ventilation.)
• Type and concentration of pollutants – different pollutants, such as particulate matter (PM2.5) or nitrogen dioxide (NO₂), affect the body in different ways.
• Individual characteristics – age, sex, diet, genetics, lifestyle, and overall health status play a significant role in determining vulnerability.

As a consequence, exposure to air pollution for brief or sustained periods of time can lead to increases in hospital admissions, mortality, and reduced life expectancy.