Secondary Pollutant
Kartavya Desk Staff
Context: A recent study by the Centre for Research on Energy and Clean Air (CREA) reveals that secondary pollutants, especially ammonium sulphate, account for nearly 34% of PM2.5 pollution in India.
About Secondary Pollutant:
• What are Secondary Pollutants?
• Secondary pollutants are not directly emitted but are formed in the atmosphere when primary pollutants (like SO₂, NOx, NH₃) undergo chemical reactions. Ammonium sulphate forms from the reaction between sulphur dioxide (SO₂) and ammonia (NH₃), both prevalent in India due to coal combustion and fertilizer use.
• Secondary pollutants are not directly emitted but are formed in the atmosphere when primary pollutants (like SO₂, NOx, NH₃) undergo chemical reactions.
• Ammonium sulphate forms from the reaction between sulphur dioxide (SO₂) and ammonia (NH₃), both prevalent in India due to coal combustion and fertilizer use.
• Key Trends from CREA Study:
• Ammonium sulphate contributes ~34% to PM2.5 mass on average across India. Thermal power plants contribute over 60% of SO₂ emissions, the main precursor. Concentration of ammonium sulphate is 2.5× higher within 10 km of coal plants. 114 of 130 NCAP cities show over 30% PM2.5 levels due to ammonium sulphate. Other secondary pollutants like ammonium nitrate also contribute up to 50% of PM2.5.
• Ammonium sulphate contributes ~34% to PM2.5 mass on average across India.
• Thermal power plants contribute over 60% of SO₂ emissions, the main precursor.
• Concentration of ammonium sulphate is 2.5× higher within 10 km of coal plants.
• 114 of 130 NCAP cities show over 30% PM2.5 levels due to ammonium sulphate.
• Other secondary pollutants like ammonium nitrate also contribute up to 50% of PM2.5.
• Health & Environmental Impact:
• Leads to chronic respiratory issues, cardiovascular problems, and premature deaths. Contributes to regional and transboundary air pollution. Indicates ineffective enforcement of flue gas desulphurisation (FGD) systems in coal plants (only 8% installed).
• Leads to chronic respiratory issues, cardiovascular problems, and premature deaths.
• Contributes to regional and transboundary air pollution.
• Indicates ineffective enforcement of flue gas desulphurisation (FGD) systems in coal plants (only 8% installed).
Relevance in UPSC Syllabus
• GS Paper 3 – Environment
• Pollution & Health Hazards: Highlights the growing burden of PM2.5 from secondary pollutants and its impact on public health, especially in urban areas. Environmental Impact Assessment: Emphasizes the need for FGD systems in thermal power plants and monitoring of precursor emissions.
• Pollution & Health Hazards: Highlights the growing burden of PM2.5 from secondary pollutants and its impact on public health, especially in urban areas.
• Environmental Impact Assessment: Emphasizes the need for FGD systems in thermal power plants and monitoring of precursor emissions.
• GS Paper 2 – Governance & Policy
• Government Policies & Interventions: Evaluates the effectiveness of regulatory mechanisms like NCAP and SO₂ control mandates in coal-fired plants. Health & Welfare Schemes: Links air quality degradation to public health outcomes, reinforcing the need for integrated environmental-health governance.
• Government Policies & Interventions: Evaluates the effectiveness of regulatory mechanisms like NCAP and SO₂ control mandates in coal-fired plants.
• Health & Welfare Schemes: Links air quality degradation to public health outcomes, reinforcing the need for integrated environmental-health governance.