The latest research confirms that air pollution can be harmful to human health and, at high or prolonged levels of exposure, can contribute to premature death. Air pollution comes from many sources, with particulate matter and ozone among the most important pollutants affecting human health. Vehicle exhaust, emissions from factories and power plants, and smoke from indoor and outdoor wood burning are important sources of particulate matter and other air pollutants.

The higher the ozone levels, the greater the risk to human health. Ozone is an extremely reactive oxidizing gas that can irritate the respiratory system and aggravate existing respiratory conditions. Research has shown that ozone can cause breathing difficulties, coughing, and asthma attacks. Children, older adults, and people with asthma or other respiratory conditions can be particularly sensitive to ozone exposure.

Airborne particulate matter can also have serious health effects, particularly when people are exposed to elevated levels over long periods. Fine particulate matter can penetrate deep into the lungs and is associated with cardiovascular and respiratory disease, lung cancer, and premature death. Particulate pollution can also aggravate asthma and other respiratory conditions.

People should recognize the importance of reducing exposure to air pollution and protecting the environment. Early prevention and effective control of pollution are essential. For indoor air, reducing pollution at its source, providing adequate ventilation when appropriate, and using a suitable air purifier can also help reduce exposure to airborne particulate matter.

By Michael Chiu, MWS, CI
Previously published in Ming Pao Daily News – Updated and Revised in 2026