Air quality improves from poor levels

After reeling under “poor” air quality for five consecutive days, the city breathed some good air on Saturday morning by recording an air quality index of 154, which comes under the category of “moderate”. Experts attributed the change in wind patterns and temperatures remaining high most of the time, which led to an improvement in the air quality.

According to the System of Air Quality Weather Forecasting and Research (SAFAR), the air quality index (AQI) for the city on Saturday morning was 154, which further increased to 161 by evening. “Strong monsoon conditions followed by the impact of tropical cyclones in the Arabian Sea had kept pollution levels low through most of 2019,” said an official from SAFAR.

PM2.5 is the smaller kind of particulate matter with diametre of not more than 2.5 micrometers. These are “fine particles” that can stay in the air for days or weeks and are small enough to invade even the narrowest of airways leading into the body. PM2.5 are the most toxic pollutant particles that are carried to lower airways of lungs and deposited on the alveolar wall, causing serious health ailments.

AQI levels for PM2.5 pollutant between 0-50 is good, 51100 is satisfactory, 101-200 is moderate, 201-300 is poor, 301400 is very poor and above 400 is severe.

Weather experts said the

Arabian Sea was currently active with a number of weather systems affecting the wind and overall weather pattern over the West coast. “A low-pressure weather system over Southeast Arabian Sea, off the Karnataka coast, is allowing an increase in cloud cover over the entire West coast and also leading to a change in the wind pattern. This has helped to improve the air quality too,” said SG Kamble, scientist, India Meteorological Department, Mumbai.

On Saturday, Colaba and Santacruz observatories recorded maximum temperatures at 32.5 degree celsius, while the minimum temperature recorded at both observatories hovered around 20 degree celsius. Humidity level was 82 per cent in South Mumbai and 57 per cent in the suburbs.

“Humidity has increased over the city under the influence of moisture incursions from the Arabian Sea, leading to a cloud cover as well. Combined with this, a low wind speed has led to the formation of a pollutant boundary layer close to the surface,” said experts.

An AQI of 165 has been predicted for Sunday.