Trophospheric Ozone (DP IB Environmental Systems & Societies (ESS))

Trophospheric Ozone

• Air pollution is a significant environmental issue, and one of the pollutants of concern is tropospheric ozone

• Tropospheric ozone, also referred to as ground-level ozone, is formed through a series of chemical reactions involving nitrogen oxides and volatile organic compounds in the presence of sunlight

  • This process occurs near the Earth's surface, primarily in the lower part of the atmosphere known as the troposphere

  • Nitrogen oxides, mainly released from human activities such as industrial processes, vehicle emissions, and combustion of fossil fuels, react with sunlight and oxygen to produce ozone

• Tropospheric ozone is highly reactive and has several negative impacts

Why is tropospheric ozone harmful?

   Plant damage

• High levels of ozone can damage plant tissues, impair photosynthesis, reduce crop yields, and cause visible symptoms such as leaf damage

• It affects a wide range of crops, including staple crops like wheat, rice, and soybeans

   Health effects of tropospheric ozone

• Tropospheric ozone irritates the respiratory system, causing coughing, throat irritation, and contributes to asthma and other respiratory conditions

• Prolonged exposure to high ozone levels can lead to chronic respiratory illnesses and reduced lung function

   Eye irritation

• Exposure to tropospheric ozone can irritate the eyes, leading to redness, tearing, and discomfort

   Material degradation

• Tropospheric ozone can damage materials such as rubber, fabrics, and certain plastics

• It accelerates the degradation and ageing of rubber components in vehicles, tires, and industrial equipment

• Ozone exposure can cause cracking, brittleness, and discolouration of materials

Don't get confused between "good" stratospheric ozone, which provides organisms with protection from harmful ultraviolet radiation, and "bad" tropospheric ozone, which can negatively impact life on Earth at high concentrations

• The impacts of tropospheric ozone extend beyond local areas, as it can be transported over long distances by wind

• This makes it a global environmental issue with the potential for widespread damage to vegetation, human health, and materials

• Reducing the emissions of nitrogen oxides and volatile organic compounds, which are precursors to tropospheric ozone formation, is crucial to mitigating its harmful effects

• Implementing air quality regulations, promoting cleaner technologies (e.g. renewable electricity generation), and adopting sustainable practices can help in controlling tropospheric ozone levels and protecting human health, crops, forests, and materials from its damaging impacts