Dehri Air Quality Index (AQI) & Air Pollution Today
Bihar, India — Real-time Air Quality Index (AQI) and PM2.5
Dehri AQI Right Now
Category: Satisfactory
Dominant Pollutant: pm10
PM2.5: 31.85 µg/m³
PM10: 94.36 µg/m³
Last updated: 2026-03-24 — Data source: Google Air Quality API (NAQI). Live NAQI values load when you visit the page.
Dehri Pollutant Levels
| Pollutant | Concentration |
|---|---|
| PM2.5 | 31.85 µg/m³ |
| PM10 | 94.36 µg/m³ |
| O₃ (Ozone) | 10.98 µg/m³ |
| NO₂ | 12.4 µg/m³ |
| SO₂ | 2.19 µg/m³ |
| CO | 1123.71 µg/m³ |
Health Advisory — Dehri
Satisfactory: Minor breathing discomfort to sensitive people.
Health Impact — Dehri
Cigarette Equivalent: Breathing this air is equivalent to smoking 1.4 cigarettes per day (based on current PM2.5 levels).
Life Expectancy Impact: Sustained exposure at this PM2.5 level could reduce life expectancy by 0.14 years (AQLI estimate, relative to WHO guideline of 5 µg/m³).
Health Recommendations for Dehri
- General Population: Acceptable air quality. Unusually sensitive people should limit prolonged outdoor exertion.
- Elderly: Minor breathing discomfort is possible.
- Children: Should be fine outdoors with normal activities.
- Lung Disease Patients: Consider reducing prolonged outdoor exertion.
Understanding Dehri Air Quality
Dehri-on-Sone, as it is formally known, occupies a unique industrial niche in Bihar as one of the state's few towns with significant heavy industry. The Dalmia Bharat cement works, operating since the 1930s from the limestone-rich Kaimur Hills that border the town, is the dominant industrial presence. Limestone quarrying in the surrounding hills generates persistent mineral dust, while the cement manufacturing process releases calcium oxide particulates, SO2, and NOx from the kilns. The Sone River, one of the Ganges' major southern tributaries, flows past the town, and its wide sandy bed serves as an additional source of wind-blown dust during dry months.
October through January is the worst period for air quality. Winter inversions over the Sone River valley-which sits in a broad depression between the Kaimur plateau to the south and the rising Gangetic plain to the north-trap cement plant emissions, quarry dust, and domestic pollution at ground level. The topographic channelling effect of the river valley can concentrate pollutants even further during periods of light winds. Brick kilns along the riverbanks add their emissions to the industrial baseline, and biomass burning in the surrounding agricultural areas elevates PM2.5 across the district. The cement factory's continuous operation means Dehri never achieves the truly clean air that non-industrial Bihar towns enjoy during the monsoon.
Monsoon rainfall of 1,000 to 1,200 mm from July through September provides the most effective atmospheric cleansing, suppressing quarry dust and washing cement particulates from the air. The Sone River floods spectacularly during peak monsoon, reshaping sandbars and temporarily eliminating riverbed dust. Pre-monsoon months from March to May bring hot winds from the west that can carry quarry dust considerable distances. Dehri's air quality challenge is fundamentally industrial-requiring emission control investment at the cement works and managed quarrying practices rather than the household-fuel interventions needed in most Bihar towns.
Primary Pollution Sources
- Cement factory emissions
- Brick kilns
- Vehicle exhaust
- Domestic biomass burning
- Industrial dust
Geography: Sone River industrial town in Rohtas district; home to Dalmia cement works and limestone quarrying operations at the edge of the Kaimur Hills
Peak pollution months: October, November, December, January
Frequently Asked Questions — Dehri
How does the cement industry affect Dehri's air quality?
The Dalmia Bharat cement works is Dehri's primary industrial polluter, releasing calcium oxide dust, SO2, and NOx from cement kilns. Associated limestone quarrying in the Kaimur Hills generates mineral dust that settles across the town. Unlike most Bihar towns where pollution is seasonal, Dehri's cement operations run year-round, creating a persistent industrial baseline that seasonal biomass and brick kiln emissions build upon.
Does the Sone River valley geography worsen Dehri's pollution?
Yes. Dehri sits in the Sone River valley between the Kaimur plateau and the Gangetic plain. This valley topography channels light winds and can concentrate pollutants, especially during winter inversions. The effect is modest compared to deep mountain valleys, but noticeable enough that Dehri experiences slightly worse stagnation events than open-plain towns at similar latitudes in Bihar.
Air Quality in Nearby Cities
- Sasaram AQI — Bihar
- Arwal AQI — Bihar
- Buxar AQI — Bihar
- Gaya AQI — Bihar
- Bodhgaya AQI — Bihar
- Bhojpur AQI — Bihar