Patna, Nov 12 (IANS): The AQI in various cities of Bihar is worsening with Darbhanga, being the most polluted city of the state recording an AQI of 400 on Saturday.

Motihari registered an AQI of 346, Chapra 314, Katihar 313 and Saharsa 309.

Patna's AQI improved to 247, slight decrease from the 300 mark recorded the previous day.

The Bihar State Pollution Control Board (BSPCB) officials claimed that the AQI index will improve in the next few days.

The people of the above mentioned cities have been witnessing AQI levels above 300 mark for the last one week.

Ashok Ghosh, the chairman of BSPCB, said: "The deterioration of air quality in various cities is due to rampant construction. Besides, cities like Patna are located on the banks of Ganga river. The sand on the bank of Ganga river mixed in the air is leading to an increase in Particulate Matter 2.5 (PM 2.5) and Particulate Matter 10 (PM 10) and deterioration of air quality."

In Patna, leaders have stated using face masks during public events or travelling on the roads.

AQI from 0 to 50 is considered as good, from 51 to 100 considered as moderate, from 101 to 150 considered as unhealthy for sensitive group, from 151 to 200 considered as unhealthy for all groups, from 201 to 300 considered as very unhealthy and from 301 to 500 hazardous for human health.