Thane air quality worsens on Diwali, AQI hits 150; noise well above limits

Thane's air quality deteriorated during Diwali. According to data released by the Thane Municipal Corporation (TMC), the city's Air Quality Index (AQI) was 95 before the festival and rose to 150 on Sunday, the day of Lakshmi Pujan.

The civic body's assessment also recorded a sharp rise in noise pollution. The daytime noise level went up to 81.3 decibels.

The TMC's pollution control department monitored the air before and during the festival. The monitoring was carried out at the Continuous Ambient Air Quality Monitoring Stations (CAQMS) at Kasarvadavali and Upvan. The same was done at the manual monitoring station in Kopri.

According to the assessment, the average amount of PM10 particles in the air was 98 micrograms per cubic metre before Diwali. On Lakshmi Pujan day it rose to 157 micrograms per cubic metre. The prescribed limit is 100 micrograms per cubic metre, so the level was above the limit.

Other pollutant gases also showed an increase. Nitrogen oxides (NOx) rose from 39 to 42 micrograms per cubic metre, while the sulphur dioxide (SO2) level rose from 16 to 30. Both gases, however, stayed within the prescribed limit.

Comparing the Diwali AQI of the past three years, Thane's AQI was 150 in 2026. It was 157 in 2025 and 146 in 2024. The AQI was slightly lower than last year, but the PM10 level recorded in 2026 was higher than in 2025.

Noise figures in Kopri showed a sharp jump. Before the festival, daytime noise there was 68.8 decibels and night-time noise was 58.3 decibels. On Lakshmi Pujan day it was recorded at 81.3 decibels in the day and 81.2 decibels at night.

The prescribed limits for residential areas are 55 decibels in the day and 45 decibels at night. The figures recorded on Diwali were well above these limits.

However, compared with Diwali in the previous two years, noise was lower this time. It was 89.2 decibels on Diwali in 2025 and 86 decibels in 2024.

The TMC has appealed to citizens to celebrate the festival responsibly, keep the use of firecrackers limited and follow measures to control noise pollution.