Lucknow, Nov 6 (IANS): Seven cities in Uttar Pradesh recorded 'poor' while four recorded 'very poor' air quality on Saturday night, according to a bulletin released by the Central Pollution Control Board.

With air quality index (AQI) of 357, Noida topped the chart in the state followed by Muzaffarnagar (332), Ghaziabad (322) and Greater Noida (312).

The seven cities with poor air quality included Jhansi (277), Prayagraj (275), Baghpat (270), Kanpur (236), Meerut (225), Lucknow (216) and Bulandshahr (219).

However, no city in the state crossed the 'severe' mark as was the case on Saturday. Only Kukrail air was 'moderate' in Lucknow. The state capital recorded AQI of 216 on Saturday which was slightly better as compared to AQI of 290 recorded on Friday.

However, as per the five monitoring stations installed by the pollution control board at five locations of Lucknow Talkatora industrial area, average AQI was recorded at 334. It reached maximum 379 at 12 a.m. on Saturday.

At Lalbagh the AQI was 261, in Central School area it was recorded 220 and at BR Ambedkar University the AQI was 165. Only Kukrail picnic spot and Gomti Nagar record moderate AQI with 147 and 159 respectively.

An AQI level between zero and 50 is considered "good", 51-100 is "satisfactory", 101-200 is "moderate", 201-300 is "poor", 301-400 is "very poor", and 401-500 is "severe".

The toxicity of air is measured by the presence of pollutants including PM2.5 (fine particulate matter), PM10 (particulate matter), NO2 (nitrogen dioxide) and SO2 (sulphur dioxide).