Kolkata's Air Quality Deteriorates as Diwali Approaches

Strategic Insights -

Kolkata's air quality is showing signs of deterioration as the rains recede and the air becomes drier. The city's air quality index (AQI) slipped into the moderate category for the first time this season, triggering concerns of a sharp rise in pollution levels after Diwali. Experts warn that pollution could climb by nearly 30% this winter, worsened by La Niña-driven atmospheric conditions. Until now, the city had enjoyed relatively clean air, thanks to consistent pre-monsoon and monsoon showers since April.

Key Takeaways:

  • Kolkata's air quality index (AQI) slipped into the moderate category for the first time this season, with AQI values of 125 and 123 recorded on Oct 13 and 14, respectively.
  • The city's AQI is expected to worsen by nearly 30% this winter, driven by La Niña conditions and atmospheric stagnation.
  • The La Niña event could trap pollutants close to the ground, exacerbating conditions in cities like Kolkata and Delhi.
  • Open burning of trash and biomass remains a critical threat to the city's air quality, particularly at night when wind speeds drop and dispersion weakens.
  • The implementation of green fireworks has had little impact on the overall pollution of the city due to the rampant sale and use of banned fireworks in their guise.
  • Diwali coincides with the onset of winter, resulting in a slow dispersal of Diwali pollution and a pile-up effect on the ambient pollution level in subsequent days.
  • The city's increased pollution levels are expected to trigger smog episodes across the Indo-Gangetic Plain and lead to increased respiratory illnesses.

Statistics:

  • AQI values of 125 and 123 recorded on Oct 13 and 14, respectively.
  • The city's AQI is expected to worsen by nearly 30% this winter.
  • La Niña event could trap pollutants close to the ground, exacerbating conditions in cities like Kolkata and Delhi.
  • 189 AQI value recorded at RBU on B T Road on Oct 14.
  • 157 AQI value recorded at Jadavpur on Oct 14.
  • 142 AQI value recorded at Victoria on Oct 14.
  • 106 AQI value recorded at Ballygunge on Oct 14.
  • 0-50 AQI range: Good air quality.
  • 51-100 AQI range: Satisfactory air quality.
  • 101-200 AQI range: Moderate air quality.

Sources:

  • Bose Institute, atmospheric scientist Abhijit Chatterjee
  • Sabuj Mancha secretary Naba Dutta
  • Times of India (publication date not specified)