Tamil Nadu Records Third Consecutive Year of Rising Deepavali Pollution Levels: TNPCB Data

Data released by the Tamil Nadu Pollution Control Board shows a consistent rise in air quality index and noise levels during Deepavali across the state between 2024 and 2026. Chennai emerged as one of the worst-affected regions, with multiple neighbourhoods recording worsening pollution despite regulatory measures and awareness campaigns.

Tamil Nadu has recorded a steady deterioration in air quality during Deepavali celebrations over a three-year period, according to a comparative assessment released by the Tamil Nadu Pollution Control Board (TNPCB). The State’s average Air Quality Index (AQI) rose nearly 18 per cent between 2024 and 2026.

Alongside air pollution, ambient noise levels also increased during the corresponding period. The TNPCB attributed the overall rise in pollution and noise levels to the bursting of firecrackers combined with variations in meteorological conditions, including wind speed, wind direction, and atmospheric stability.

According to the official release, the average AQI across 39 monitoring locations in 17 districts increased from 143.46 in 2024 to 161.69 in 2025, and further to 168.97 in 2026. The data shows a sharp increase of 12.7 per cent in 2025 over the previous year, followed by an additional 4.5 per cent increase in 2026.

The monitoring exercise was conducted by the Board between November 1 and 9, covering 39 air quality monitoring locations and 34 noise monitoring locations across the State. The specific Deepavali survey was conducted on November 8. The findings indicate that the deterioration in air quality has continued for three consecutive years despite ongoing awareness campaigns and restrictions on firecracker bursting.

Out of the 39 locations monitored in 2026, 25 recorded an increase in AQI compared to 2025, while 14 registered an improvement.

Chennai continued to be among the worst-affected areas in the state, with several neighbourhoods recording a consistent deterioration in air quality over the three-year timeline. Valasaravakkam recorded the highest AQI at 343 in 2026, compared with 332 in 2025 and 287 in 2024. Nungambakkam recorded an AQI of 332 against 326 in 2025 and 230 in 2024.

Other neighbourhoods also experienced marked changes. Sowcarpet witnessed a sharper deterioration, with its AQI rising from 193 in 2024 to 260 in 2025 and 311 in 2026. T Nagar recorded a steady increase from 203 to 273 and 306 over the same period, while Triplicane's AQI increased from 197 in 2024 to 227 in 2025 and 267 in 2026. Thiruvottiyur was an exception, where the AQI declined from 207 in 2025 to 183 in 2026, though it remained above the 150 recorded in 2024, according to the TNPCB data.

The three-year comparison of ambient noise levels across 34 locations followed a similar upward trajectory. The average noise level on Deepavali day increased from approximately 73.94 decibels (dB(A)) in 2024 to 75.70 dB(A) in 2025 and 76.73 dB(A) in 2026. Similarly, the pre-Deepavali average noise level increased from approximately 59.67 dB(A) in 2024 to 60.29 dB(A) in 2025 and 61.06 dB(A) in 2026.

"The consistent rise in pollution levels over three consecutive years highlights the ongoing challenge of balancing traditional festivities with environmental compliance. From a business and public policy perspective, this trend underscores the need for deeper innovation in green alternatives and stricter adherence to regulatory frameworks. Sustainable urban planning must factor in these predictable seasonal spikes to protect public health and manage urban environmental impact effectively." — Dr. Shishir Gupta, Founder & CEO, StartupLanes