Size Matters

What is Ozone (O3)?

Ozone (O3) is a gas formed by solar ultraviolet radiation (sunlight) and oxygen molecules.

While it is a naturally occurring compound in the atmosphere that plays a vital role in blocking out harmful ultraviolet rays from the sun, at the ground level, ozone is toxic.

Where does it come from?

While other pollutants are emitted directly into the air by various sources, ozone is simply created by sunlight acting on nitrogen oxides (NOx) and volatile organic compounds (VOCs) in the atmosphere. For this reason, ozone is the most pervasive and most difficult to control of the six pollutants.

Sources of VOCs: motor vehicles, chemical plants, refineries, and natural sources such as volcanoes, vegetation and bacteria.

Sources of NOx: motor vehicles, power plants, and combustion sources.

How does it affect our health?

Ozone is a respiratory irritant that can cause symptoms including:

• Shortness of breath
• Pain during deep breaths
• Wheezing and coughing

Long term exposure to high levels of ozone may lead to reductions in lung function, inflammation of the lung lining and increased respiratory discomfort.

Environmental effects?

Ozone can have a profound impact on sensitive vegetation. These impacts include:

• Interference with the ability of plants to produce and store food
• Physical damage
• Increased susceptibility of sensitive plant species to disease, damage from insects, etc.