Patna: A brief shift in weather conditions brought some improvement in air quality across parts of Bihar on Thursday, though pollution levels in many cities remained a cause for concern.
In Patna and its adjoining areas, dense fog and overnight dewfall helped lower pollution levels. Danapur, which had recorded an air quality index (AQI) of 268 on Wednesday, saw a marked improvement on Thursday, with the index falling to 162. Despite the drop, air quality in the capital region continued to fall in the “moderately polluted” category.
Biharsharif emerged as the most polluted city in the state, registering an AQI of 247, followed closely by Munger at 226. At the other end of the spectrum, Chhapra recorded the cleanest air, with an AQI of 77, placing it firmly in the satisfactory category.
Air quality was assessed as satisfactory in four cities — Arrah, Chhapra, Motihari and Samastipur. In Patna city, Shikarpur recorded an AQI of 132, Muradpur 180 and Rajvanshi Nagar 165, indicating moderate pollution. Overall, 14 cities across Bihar continued to experience moderate pollution levels.
Meteorological officials said falling temperatures during winter increase air density, causing pollutants to linger closer to the ground. The state’s geographical conditions, particularly loose soil in several regions, also contribute to higher concentrations of dust particles. Ongoing construction work across urban areas has further exacerbated air quality concerns. Experts noted that regular watering of roads could help suppress dust and improve local air conditions.
Understanding air quality categories
Air quality is measured through the AQI, which reflects its health impact. An AQI of 0–50 is good with minimal risk, while 51–100 is satisfactory and generally safe. Levels between 101 and 200 are moderately polluted and may affect sensitive groups. An AQI of 201–300 is poor and can impact everyone’s breathing. Readings of 301–400 are very poor with serious health effects, and values above 400 are severe, posing emergency-level risks even to healthy people.
Air Quality Index across Bihar cities
| City | AQI |
| Arrah | 84 |
| Chhapra | 77 |
| Motihari | 90 |
| Samastipur | 80 |
| Aurangabad | 185 |
| Gaya | 184 |
| Kishanganj | 182 |
| Araria | 156 |
| Begusarai | 148 |
| Bettiah | 101 |
| Bhagalpur | 164 |
| Hajipur | 158 |
| Katihar | 133 |
| Muzaffarpur | 149 |
| Rajgir | 179 |
| Saharsa | 149 |
| Sasaram | 150 |
| Siwan | 107 |
| Biharsharif | 247 |
| Munger | 226 |
