Gangtok — Pollution Health Impact
788 days of CPCB data (2022–2024), translated through WHO 2021, Berkeley Earth and EPIC AQLI methods. Based on CPCB station data, 2016–present.
Sikkim · Live Gangtok AQI →
Living in Gangtok is the population-level health-equivalent of smoking 1.3 cigarettes a day — roughly 490 cigarettes a year. On average, that chronic exposure shortens life expectancy by about 2.4 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 Gangtok meet?
24-hour PM2.5 compliance vs WHO 2021 targets.
- AQG131 days (16.6%)
- IT-4158 days (20.1%)
- IT-3362 days (45.9%)
- IT-274 days (9.4%)
- IT-150 days (6.3%)
- Above IT-113 days (1.6%)
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 Gangtok's 2.4 year estimate.
- Heart + stroke: 1.6y
- COPD: 0.3y
- Child ALRI: 0.3y
- Lung cancer: 0.1y
Worst and best months
Drill into full monthly pattern on the seasonal Gangtok page →
High-risk days for vulnerable residents
- Days above WHO IT-3 (37.5 µg/m³) — pregnancy & infant risk elevated
- 137 (17.4%)
- Days above WHO IT-1 (75 µg/m³) — high risk for children under 5
- 13 (1.6%)
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 Gangtok compares to nearby cities
- Similar exposureGadag1.5 cigs/day · 2.7 y lost · +0.1 vs Gangtok
- Similar exposureTiruchirappalli1.4 cigs/day · 2.5 y lost · +0.1 vs Gangtok
- Cleaner peerMadurai1.3 cigs/day · 2.3 y lost · -0.0 vs Gangtok
- Dirtier peerAriyalur1.3 cigs/day · 2.4 y lost · +0.0 vs Gangtok
What the numbers say
Overview
Gangtok's air pollution translates to about 1.3 passive cigarettes per resident per day. That's 490 cigarette-equivalents annually, inhaled without choice.
The data story
EPIC's AQLI research attributes about 2.4 life-years lost per person from this chronic exposure. The WHO Air Quality Guideline was met on just 131 of 788 days (16.6%); 13 days (1.6%) exceeded even the 75 µg/m³ Interim Target-1 threshold.
Why this pattern
The burden concentrates in March — when the average cigarette-equivalent climbs to 2.0/day — and eases in July (0.9/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 137 days (17.4%) above WHO IT-3 meaningfully lowers exposure — especially for pregnant residents and children under 5.