Chapra — Pollution Health Impact
966 days of CPCB data (2021–2024), translated through WHO 2021, Berkeley Earth and EPIC AQLI methods. Based on CPCB station data, 2016–present.
Bihar · Live Chapra AQI →
Living in Chapra is the population-level health-equivalent of smoking 4.4 cigarettes a day — roughly 1,616 cigarettes a year. On average, that chronic exposure shortens life expectancy by about 9.1 years per resident.
Cigarette-equivalence (Berkeley Earth 2015) and life-years lost (EPIC AQLI) are peer-reviewed communication heuristics, not clinical diagnoses. Full sources linked on the methodology page.
Headline impact numbers
Cigarettes/day by year
Annual average cigarette-equivalent.
Clean-air days (NAQI ≤ 50) by year
Days when NAQI stayed in the “Good” band.
Which WHO tier did Chapra meet?
24-hour PM2.5 compliance vs WHO 2021 targets.
- AQG4 days (0.4%)
- IT-411 days (1.1%)
- IT-374 days (7.7%)
- IT-291 days (9.4%)
- IT-1224 days (23.2%)
- Above IT-1562 days (58.2%)
WHO AQG (15) · IT-4 (25) · IT-3 (37.5) · IT-2 (50) · IT-1 (75) µg/m³ (24-hour PM2.5).
Life-years lost, by disease
Applying WHO's global attribution (68/14/14/4) to Chapra's 9.1 year estimate.
- Heart + stroke: 6.2y
- COPD: 1.3y
- Child ALRI: 1.3y
- Lung cancer: 0.4y
Worst and best months
Drill into full monthly pattern on the seasonal Chapra page →
High-risk days for vulnerable residents
- Days above WHO IT-3 (37.5 µg/m³) — pregnancy & infant risk elevated
- 877 (90.8%)
- Days above WHO IT-1 (75 µg/m³) — high risk for children under 5
- 562 (58.2%)
Source: WHO 2021 AQG interim-target risk framework; WHO 2024 ambient-air fact sheet identifies children under 5 and pregnant residents as the most vulnerable groups.
How Chapra compares to nearby cities
- Similar exposureMuzaffarpur4.7 cigs/day · 9.7 y lost · +0.3 vs Chapra
- Similar exposureSiwan4.7 cigs/day · 9.6 y lost · +0.3 vs Chapra
- Cleaner peerBāghpat4.4 cigs/day · 8.9 y lost · -0.1 vs Chapra
- Dirtier peerBhagalpur4.4 cigs/day · 9.1 y lost · +0.0 vs Chapra
What the numbers say
Overview
Chapra's air pollution translates to about 4.4 passive cigarettes per resident per day. That's 1,616 cigarette-equivalents annually, inhaled without choice.
The data story
EPIC's AQLI research attributes about 9.1 life-years lost per person from this chronic exposure. The WHO Air Quality Guideline was met on just 4 of 966 days (0.4%); 562 days (58.2%) exceeded even the 75 µg/m³ Interim Target-1 threshold.
Why this pattern
The burden concentrates in January — when the average cigarette-equivalent climbs to 7.9/day — and eases in July (2.0/day). Globally, WHO attributes 68% of PM2.5 deaths to heart disease and stroke, with the remainder split across COPD, childhood ALRI, and lung cancer.
What to do with this
Cigarette-equivalence is a communication tool, not a medical verdict. Still, the direction is clear: time indoors with a HEPA unit and a good-fit mask outdoors during the 877 days (90.8%) above WHO IT-3 meaningfully lowers exposure — especially for pregnant residents and children under 5.