In an alarming reflection of deteriorating air quality in the state, the top three most polluted towns out of 177 in the country on Sunday were fromBihar, with the air quality index (AQI) plunging to severe (above 400) level.Motihariwas on top of the list withAQIat 423, closely followed by 411 in Darbhanga and 401 in Siwan.
The air quality of 12 cities monitored nationally figured in the very poor list, of which 10 were from Bihar. Patnas AQI level jumped 21 notches, from 299 (poor) on Saturday to 320 (very poor) on Sunday, according to the data compiled by the Central Pollution Control Board (CPCB) at 4pm, which is the Average of the past 24 hours.
The other cities experiencing very poor day included Begusarai (399), Buxar (362), Samastipur (357), Katihar (355), Purnia (348),Saharsa(326), Muzaffarpur (322), Bhagalpur (319) and Chhapra (317).The overall AQI of Patna was based on the readings of six air monitoring stations, out of which five were in the very poor category, including Patna City (341), BIT-Mesra (320), Eco Park (320), DRM office-Khagaul (309) and Planetarium (304). SK Memorial Hall recorded the AQI at 290 (poor zone). The average concentrations of PM 2.5 (particulate matter less than 2.5 micron) stood at 102 micrograms per cubic metre (g/m3) while the PM 10 (particulate matter less than 10 micron) was recorded at 174 g/m3 on Sunday. An AQI between zero and 50 is considered good, 51-100 satisfactory, 101-200 moderate, 201-300 poor, 301-400 very poor and 401-500 severe.