Hyderabad: Winter not only made denizens in the city shiver this season, but also made the air quality dip a bit, from the official classification of ‘good’ to a not so good ‘moderate’.Though the lockdown with industries remaining shut and vehicles staying off the roads, and the intense monsoon that followed brought down pollution levels, air quality has again deteriorated in the city during the winter with the Air Quality Index (AQI) rising sharply in the last two months. According to Telangana State Pollution Control Board (TSPCB) data, AQI in several parts slipped from ‘Good’ to ‘Moderate’ category. The air quality in different monitoring stations has started to fall ever since the monsoon bid adieu to the State in October.AQI levels of 0-50 are indexed under the ‘Good’ category, 51-100 under ‘Satisfactory’, 101-200 under ‘Moderate’, 201-300 under ‘Poor’, 301-400 under ‘Very Poor’, and above 400 under the ‘Severe’ category. If the AQI recorded by the monitoring station in the University of Hyderabad area was 93 in October, the same shot up to 141 in December. Similarly, the AQI in Kukatpally and Madhapur rose from 87 and 75 to 107 and 109 respectively.In areas such as Uppal, MGBS, Abids and Charminar, where vehicular movement is high, the AQI shot up in November and December, soon after temperature dipped in the city. According to PCB officials, even though pollution drops considerably during monsoon as pollutants get washed out, it goes up again as winter sets in.“The cold weather conditions when combined with fog block pollutants coming from vehicles and industries while construction activities also contribute to air pollution,” a senior official said.The Nehru Zoological Park, which was in the ‘Good’ category in monsoon, has slipped to the ‘Moderate’ category. The AQI during the last five months in this locality has gone up from 43 to 192, while in Sanathnagar, it rose from 25 in August to 192 in December. At Balanagar, which is surrounded by several industries, the AQI went up from 98 in October to 157 in December. In Jeedimetla, it shot up from 102 to 145 in the last two months.On the other hand, pollution levels compared to previous years have come down a bit as no area in the city is in ‘Poor’ category this time. Usually, AQI in every winter in localities such as UoH, Zoo Park and Sanathnagar fall to be in the ‘Poor’ category.