Haze, humidity lead to rise in Mumbai’s pollution levels

The city witnessed hazy conditions with high humidity levels and cloud cover on Saturday, leading to further rise in air pollution level.

The city witnessed hazy conditions with high humidity levels and cloud cover on Saturday, leading to further rise in air pollution level.

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Some parts of the city recorded light rain, with thundershowers reported along the outskirts of the city. The absence of wind speed did not disperse pollutants leading to poor air quality, said researchers.

Pollutant-measuring indicator air quality index (AQI) was recorded at 121 (moderate) on Saturday – the worst since March. It was 118 (moderate) on Friday. An AQI of 111 (moderate) has been predicted for Sunday.

According to the System of Air Quality Weather Forecasting and Research (SAFAR), Saturday’s AQI was an average of nine locations in the city as the station at Bandra-Kurla Complex has been defunct for over a week.

While major locations in the city recorded ‘moderate’ air quality, the highest pollution levels were witnessed at Navi Mumbai (193), followed by Andheri (176) and Mazagaon (166). Colaba and Bhandup had the cleanest air with satisfactory air quality at 71 and 70, respectively.

SAFAR categorises AQI levels for PM2.5 in the 0-50 range as good; 51-100 as satisfactory; 101-200 as moderate; 201-300 as poor; 301-400 as very poor and above 400 as severe.

Humidity levels were at 89% in south Mumbai and 81% in the suburbs. “Owing to high moisture in the air, the city recorded higher pollution levels on Saturday, as pollutant carrying capacity increases when there is more humidity. Also, wind speed is very low characteristic to the withdrawal period of monsoon,” said Gufran Beig, project director, SAFAR.

Meanwhile, the suburbs and south Mumbai recorded 0.2mm and 0.3mm rain between 8.30am and 5.30 pm on Saturday. Thane recorded 5.6mm rainfall. The city and suburbs could expect partly cloudy conditions on Sunday with the possibility of light rain.

“The presence of low pressure weather system over Bay of Bengal is activating monsoon currents over central India, leading to thundershowers for the coast and interior Maharashtra,” said KS Hosalikar, deputy director general western region, India Meteorological Department.

AQI through the week

Monday -50 (Good)

Tuesday- 68 (Satisfactory)

Wednesday-78 (Satisfactory)

Thursday-97 (Satisfactory)

Friday-118 (Moderate)

Saturday - 121 (Moderate)

Important air quality dates this year

•Prior to Friday, last time the city recorded high pollution levels was a week before the first phase of lockdown was implemented. On March 17, the AQI was 272 (poor), on March 18 it was 172 (moderate) and on March 19 it was 130 (moderate)

•During the lockdown, the highest recorded AQI was on May 17 at 90 (satisfactory)

•Mumbai recorded its cleanest air since the monitoring began on June 30 with an AQI of 12 (good)

(Source: SAFAR)