Tropospheric Ozone Impacts (HL) (DP IB Environmental Systems & Societies (ESS))

Direct Impacts of Tropospheric Ozone

Biological effects

• Damage to plant cuticles and membranes:

  • Tropospheric ozone damages the outer layer (cuticle) of plant leaves

  • It disrupts cellular membranes, affecting nutrient and water balance

  • Leads to reduced photosynthesis and slower plant growth

    • E.g. crops like wheat and soybeans show reduced yields in regions with high ozone levels

• Eye irritation in humans and mammals:

  • Causes stinging and redness in the eyes

  • Common in urban areas with high ozone concentrations during sunny periods

• Respiratory illnesses in humans:

  • Inhalation of tropospheric ozone inflames the airways

    • This causes coughing, throat irritation, and shortness of breath

    • This aggravates asthma, bronchitis, and other chronic respiratory diseases

Physical effects

• Damage to fabrics:

  • Ozone accelerates the deterioration of natural fibres like cotton and synthetic fibres like nylon

    • This reduces the lifespan of outdoor clothing and tents

• Damage to rubber materials:

  • Reacts with natural and synthetic rubbers, causing cracking and brittleness

  • Commonly affects tyres, seals, and gaskets in urban and industrial areas

• 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

Indirect Impacts of Tropospheric Ozone

Societal costs

• Increased healthcare costs:

  • Tropospheric ozone exposure increases respiratory and cardiovascular illnesses

    • This leads to higher healthcare expenses

  • Governments and families must spend more on treatments and hospitalisations

• Strain on healthcare systems:

  • Hospitals and clinics can become overwhelmed during high-ozone periods

    • This is due to a surge in patients with respiratory distress

    • E.g. in the United States, healthcare costs rise during ozone peaks in summer, particularly in cities like Los Angeles and Houston

  • Emergency services may face resource shortages during these times

Lost economic output

• Reduced workforce productivity:

  • Workers exposed to high ozone levels may experience health problems

    • This leads to missed workdays

  • Fatigue, breathing difficulties, and hospital visits reduce overall productivity

• Crop losses:

  • Ozone reduces agricultural yields

    • This impacts farmers’ incomes and increases food prices

• Cost of material damage:

  • Repairing or replacing materials like rubber and fabrics degraded by ozone adds to economic costs

    • E.g. increases costs for industries that have to replace materials and equipment due to this problem

Different impacts on communities

• Disproportionate effects on poorer communities:

  • Poorer communities often live closer to industrial areas and busy roads, where ozone levels are highest

  • Limited access to healthcare worsens the health outcomes for these communities

• Greater vulnerability to economic losses:

  • Poorer populations depend more on physical labour, which is directly affected by health problems caused by ozone

    • Farmworkers and outdoor labourers in polluted areas face the highest risks

  • These factors widen social inequality and health outcomes between different groups in society