Gaya — Pollution Health Impact
2,844 days of CPCB data (2016–2024), translated through WHO 2021, Berkeley Earth and EPIC AQLI methods. Based on CPCB station data, 2016–present.
Bihar · Live Gaya AQI →
Living in Gaya is the population-level health-equivalent of smoking 3.9 cigarettes a day — roughly 1,417 cigarettes a year. On average, that chronic exposure shortens life expectancy by about 7.9 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 Gaya meet?
24-hour PM2.5 compliance vs WHO 2021 targets.
- AQG5 days (0.2%)
- IT-480 days (2.8%)
- IT-3226 days (7.9%)
- IT-2374 days (13.2%)
- IT-1730 days (25.7%)
- Above IT-11,429 days (50.2%)
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 Gaya's 7.9 year estimate.
- Heart + stroke: 5.4y
- COPD: 1.1y
- Child ALRI: 1.1y
- Lung cancer: 0.3y
Worst and best months
Drill into full monthly pattern on the seasonal Gaya page →
High-risk days for vulnerable residents
- Days above WHO IT-3 (37.5 µg/m³) — pregnancy & infant risk elevated
- 2,533 (89.1%)
- Days above WHO IT-1 (75 µg/m³) — high risk for children under 5
- 1,429 (50.2%)
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 Gaya compares to nearby cities
- Similar exposureSaharsa4.2 cigs/day · 8.7 y lost · +0.4 vs Gaya
- Similar exposureHanumāngarh4.2 cigs/day · 8.6 y lost · +0.3 vs Gaya
- Cleaner peerDhanbad3.8 cigs/day · 7.8 y lost · -0.1 vs Gaya
- Dirtier peerDurgapur3.9 cigs/day · 8.0 y lost · +0.0 vs Gaya
What the numbers say
Overview
Gaya's air pollution translates to about 3.9 passive cigarettes per resident per day. That's 1,417 cigarette-equivalents annually, inhaled without choice.
The data story
Using the Air Quality Life Index coefficient from EPIC at the University of Chicago, that long-run exposure reduces average life expectancy by roughly 7.9 years per resident. Of the 2,844 days on record, only 5 (0.2%) met the WHO 24-hour guideline of 15 µg/m³, while 1,429 days (50.2%) were above the loosest WHO Interim Target-1 (75 µg/m³).
Why this pattern
Seasonality matters: December is Gaya's worst month (6.3 cigs/day equivalent) and August is the best (2.1 cigs/day). Per WHO's 2024 attribution, 68% of PM2.5-attributable deaths globally come from ischaemic heart disease and stroke, 14% from COPD, 14% from acute lower-respiratory infections in children under 5, and 4% from lung cancer.
What to do with this
These numbers are communication heuristics, not a clinical diagnosis — but they make the stakes legible. Low-cost actions stack: check 24-hour PM2.5 daily, wear an N95 in winter mornings, and run a HEPA purifier indoors during peak months. Pregnant residents and children under 5 are most at risk (WHO 2024) and benefit most from clean-air interventions on the 2,533 days (89.1%) when PM2.5 sits above WHO IT-3 (37.5 µg/m³).