Syllabus: GS-III & V – Air Pollution

Why in the News?

A recent satellite-driven assessment by the Centre for Research on Energy and Clean Air (CREA) has revealed that 11 districts of Assam are now among the top 50 most polluted districts in India. The findings challenge the perception that Assam’s greenery guarantees clean air, placing the State alongside metropolitan pollution hotspots like Delhi.

Key Findings of the CREA Study

• Assam and Delhi together account for 22 out of the top 50 most polluted districts.
• All 34 monitored districts in Assam exceeded NAAQS for PM2.5 in 2024.
• Assam, Tripura, Punjab, Delhi show year-round non-compliance, even during monsoon.
• 21 Assam districts exceeded PM2.5 even during monsoon—when natural cleansing typically lowers pollution.

Why Assam Is Becoming a Pollution Hotspot

1. High Baseline Emissions

Despite natural vegetation, rising PM2.5 levels are caused by:

• Biomass burning (agricultural residue, household fuels)
• Industrial emissions (oil refineries, brick kilns, tea factories)
• Transport sector growth and traffic congestion
• Rapid urbanisation in Guwahati, Silchar, Dibrugarh

2. Seasonal Pollution Patterns

Assam now ranks among the top five polluted States in:

• Winter – inversion + biomass burning
• Summer – tea processing emissions, dust
• Monsoon – unexpectedly high due to persistent baseline emissions

Districts Most at Risk

Previous assessments identify:

• Kamrup Metropolitan, Nagaon, Dibrugarh, Tinsukia, Cachar
• Sivasagar, Jorhat, Golaghat, Karbi Anglong
• Hailakandi, Sonitpur

Understanding the Key Terms

• PM2.5: Fine particulate matter (≤2.5 microns) causing lung & heart diseases.
• NAAQS: National Ambient Air Quality Standards by CPCB.
• Airshed: A zone where air pollutants mix within shared boundaries.
• Baseline emissions: Regular emissions irrespective of season.
• Satellite-based monitoring: Remote sensing to track pollution beyond ground station limits.

Impact on Assam

1. Health Effects

• Rising respiratory illnesses (asthma, COPD).
• Higher risks for children and elderly.
• Guwahati & industrial towns show increasing hospitalisation rates.

2. Environmental Damage

• Stress on forests and tea gardens.
• Soil and water acidification.
• Long-term crop productivity decline.

3. Economic Costs

• Higher healthcare expenditure.
• Lower tea quality due to particulate deposition.
• Pollution-driven migration out of urban areas.

CREA’s Recommendations for Assam

1. District-Level Air Quality Action Plans

Use satellite hotspot mapping for targeted interventions.

2. Regional Approach

Cooperation with Tripura, Meghalaya, Nagaland; airsheds overlap.

3. Target Major Pollution Clusters

• Thermal and power plants
• Industrial zones (refineries, tea processing)
• Transport emissions
• Biomass burning control

4. Strengthen Monitoring

• Expand CAAQMS network
• Utilise NCAP funds effectively

Conclusion

Assam is no longer the “clean air” region it once was. With all 34 districts exceeding PM2.5 standards, the State is emerging as a major pollution hotspot. Tackling the crisis requires district-focused action plans, strict enforcement, transition to clean fuels, and region-wide coordination. Without timely intervention, Assam’s environmental and public health burden will intensify.

Exam Hook: Key Takeaways

• 11 Assam districts among India’s top 50 polluted.
• State shows year-round NAAQS non-compliance.
• 21 districts crossed PM2.5 limits even during monsoon.
• Major sources: biomass burning, industry, transport, urbanisation.
• Based on satellite monitoring—CREA analysis.
• NCAP + district action plans essential.

Mains Practice Question (One Line)

Q. Despite its rich green cover, Assam is emerging as a major PM2.5 pollution hotspot. Analyse the factors responsible and suggest a district-level strategy to tackle the rising air pollution.