Siliguri — Pollution Health Impact
1,910 days of CPCB data (2018–2024), translated through WHO 2021, Berkeley Earth and EPIC AQLI methods. Based on CPCB station data, 2016–present.
West Bengal · Live Siliguri AQI →
Living in Siliguri is the population-level health-equivalent of smoking 2.5 cigarettes a day — roughly 906 cigarettes a year. On average, that chronic exposure shortens life expectancy by about 4.9 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 Siliguri meet?
24-hour PM2.5 compliance vs WHO 2021 targets.
- AQG19 days (1.0%)
- IT-4350 days (18.3%)
- IT-3443 days (23.2%)
- IT-2216 days (11.3%)
- IT-1430 days (22.5%)
- Above IT-1452 days (23.7%)
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 Siliguri's 4.9 year estimate.
- Heart + stroke: 3.3y
- COPD: 0.7y
- Child ALRI: 0.7y
- Lung cancer: 0.2y
Worst and best months
Drill into full monthly pattern on the seasonal Siliguri page →
High-risk days for vulnerable residents
- Days above WHO IT-3 (37.5 µg/m³) — pregnancy & infant risk elevated
- 1,098 (57.5%)
- Days above WHO IT-1 (75 µg/m³) — high risk for children under 5
- 452 (23.7%)
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 Siliguri compares to nearby cities
What the numbers say
Overview
Living in Siliguri carries a daily PM2.5 dose that Berkeley Earth compares to 2.5 cigarettes a day. Over a year, residents absorb the equivalent of 906 cigarettes.
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 4.9 years per resident. Of the 1,910 days on record, only 19 (1.0%) met the WHO 24-hour guideline of 15 µg/m³, while 452 days (23.7%) were above the loosest WHO Interim Target-1 (75 µg/m³).
Why this pattern
Seasonality matters: February is Siliguri's worst month (4.5 cigs/day equivalent) and August is the best (1.1 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 1,098 days (57.5%) when PM2.5 sits above WHO IT-3 (37.5 µg/m³).