HYDERABAD: Light showers and moderate wind speed in the city brought citizens some relief from air pollution. The last two weeks has seen dramatic variations in the weather and quality of air.
There have been chilly, rainy and warmer days. Pollution is mainly a by-product of fossil fuel emissions and other human activities. But change in weather determines air quality on any given day more than any other factor.
According to pollution experts, light scattered rainfall in the State and mild wind speeds have marginally brought down the city’s overall Air Quality Index (AQI).
In layman’s terms, this means pollution has come down and we are breathing cleaner air. As per the TSPCB data, at 7 pm on Friday, the city’s air quality was recorded at 58 which is in ‘good category’.
Speaking to Express, Sagar Dhara, a city-based environmentalist and air quality expert, explains how the interplay of key weather variables decides the quality of the air you breathe.
He said, “Rain washes away pollutants and can quickly clean the air. Particulate Matters (PMs) are scrubbed down by the rain. Other than that, when other harmful gases come in contact with rain droplets, they come down to earth in form of mild acid rain. Further, if it is cloudy, the ozone formation is low, which is a major pollutant in the atmosphere.”
Another air pollution expert said that pollutants tend to increase during winters due to inversion process when wind speeds are not more than about 10km/hr.
Moderate wind speed, which is more than 10 km/hr also leads to the dispersal of air pollutants, which in turn clears the air.
On Friday, of the total six air quality monitoring stations, two recorded AQI in the ‘good category’ and the rest three recorded AQI at ‘satisfactory category’. There was no data available for one station.
AQI PM 2.5
Central University 44 27
Bollarum 59 34
IDA Pashamylaram 47 45
Zoo Park 78 75
Sanathnagar 69 70