Surface Ozone Pollution

• 10 Apr 2025

Why in News? 

Indian Institute of Technology (IIT) Kharagpur study reveals that surface ozone pollution is severely affecting India's major food crops, especially in the Indo-Gangetic Plain and central India. 

  

Key Points 

• About Surface Ozone Pollution: 
  • Surface ozone (O₃) pollution refers to the excess presence of ozone at the Earth’s surface, which is formed through chemical reactions in the atmosphere.   
    • Unlike the ozone layer in the stratosphere, which protects life from harmful ultraviolet radiation, Surface ozone is a harmful pollutant that poses significant health risks and environmental damage.  
• About the study: 
  • Surface ozone pollution is damaging major food crops such as wheat, rice, and maize. 
  • The study argues that rising ozone pollution jeopardizes India's progress toward Sustainable Development Goal 1 (No Poverty) and Goal 2 (Zero Hunger) by 2030. 
  • Declining crop yields could directly affect livelihoods and food access, especially for vulnerable populations. 
  • Key Findings of the Study: 
    • The research at the Centre for Oceans, River, Atmosphere and Land Sciences (CORAL), highlights the “lesser-known but potent” threat posed by surface ozone. 
      • Ozone acts as a strong oxidant that damages plant tissues, causes foliar injuries, and leads to significant drops in crop productivity. 
    • Using data from the Coupled Model Intercomparison Project Phase-6 (CMIP6), the study assessed both historical and future trends of ozone-induced damage. 
      • Without adequate mitigation, wheat yields may decline by up to 20%, while rice and maize could see losses of around 7%. 
      • In the worst-case scenarios, ozone exposure in key agricultural zones could exceed safe limits by six times. 
    • The research warns that ozone-related yield losses could undermine India’s ability to ensure food security at home and impact food grain exports to Asian and African nations. 
  • Gaps in Current Air Quality Initiatives: 
    • The National Clean Air Programme (NCAP) largely focuses on urban air pollution, leaving agricultural regions underserved. 
    • The study highlights the need for targeted interventions to monitor and curb surface ozone pollution in farmlands. 
  • Call for Policy Action: 
    • The researchers advocate for urgent policy measures to reduce ozone emissions and protect crop health. 
    • Effective pollution control strategies in agricultural areas could boost food production and help meet both national and global food security goals. 

 Formation of Surface Level Ozone 

• Surface-level ozone is a secondary pollutant, meaning it is not directly emitted but formed through chemical reactions between nitrogen oxides (NOx) and volatile organic compounds (VOCs).  
  • NOx (emitted by vehicles, power plants, and industrial processes) and VOCs (emitted from vehicles, petrol pumps, solvents, and waste burning).  
• These reactions occur in the presence of sunlight, making ozone formation more significant during sunny days and warmer seasons. 

 National Clean Air Programme (NCAP)  

• About:  
  • The NCAP aims to systematically address air pollution by involving all stakeholders and ensuring necessary action.  
  • Under NCAP, 131 cities have been identified for implementation of city specific action plans.  
• Objective:   
  • This is the first attempt in the country to develop a national framework for air quality management with the goal of time-bound reduction .  
  • It aims to reduce the concentration of coarse (PM10) and fine particles (PM2.5) by at least 20% over the next five years (base year for comparison – 2017).