Mumbai After inhaling heavily polluted air through the Diwali weekend, the city finally got a breath of relatively fresh air on Sunday. The air quality index (AQI) — a pollution-measuring indicator — fell from 319 (very poor) on Friday (a day after Diwali) to 190 (moderate) on Saturday and 86 (satisfactory) on Sunday. The System of Air Quality Monitoring Weather Forecasting and Research (SAFAR), which monitors air quality at 10 locations in Mumbai, predicted ‘satisfactory’ air quality for Monday, with an estimated AQI of 92. “Air pollution [on Monday] poses little or no risk,” said the health statement issued by SAFAR. Researchers said fast-moving winds had dispersed pollutants that had accumulated during Diwali from firecrackers. “We expect the city’s air quality to remain in the satisfactory category unless there is a drop in temperatures. The wind speed over the city increased between Saturday night and Sunday morning, which has not allowed the layer of pollution to be stagnant close to the surface,” said Gufran Beig, project director, SAFAR.“No other city has recorded such a significant decline in pollution levels. The sudden shift in wind patterns is unique to Mumbai, and sea breeze along with a drop in humidity have swept away pollutants,” Beig said.Of the 10 locations in Mumbai, Borivli and Navi Mumbai recorded the most polluted air on Sunday, with AQI levels at 121 and 112, respectively, both falling under the ‘moderate’ category. While a majority of locations recorded ‘satisfactory’ air, Chembur had the cleanest air with an AQI of 48 (good).An AQI level from 0-50 is considered good, 51-100 is satisfactory, 101-200 is moderate, 201-300 is poor, 301-400 is very poor, and 401 and above is severe.On Sunday, Mumbai also recorded the cleanest air across four major cities — Delhi (324 very poor), Pune (110 moderate), and Ahmedabad (177 moderate).The city on Friday had recorded its worst post-Diwali air in three years. The levels of tiny particulate matter — small particles predominantly a part of dust 10 microns in size that can penetrate into the lungs and enter the bloodstream — were five times the safe limit.