The ranking
Annual mean PM2.5 → cigarettesMoving is quitting
And Bali?
The question everyone asks. Bali sells clean air and green rice terraces. The reality is scooter exhaust, open burning of household waste and dry-season haze drifting in from Java. It is not Zurich. It is also not Jakarta.
Denpasar's annual average sits in the same bracket as Warsaw or Istanbul. Away from the south-coast traffic the readings drop — but almost nowhere out there has a monitoring station, so nobody can prove it.
Open the full page →How the number is made
The rule
Physicists Richard and Elizabeth Muller (Berkeley Earth) compared the particle mass a smoker inhales with the mass you inhale from city air. One cigarette works out to about 22 µg/m³ sustained over a day. It is a mass equivalence, not a claim that smog and smoke are chemically identical.
The data
Annual mean PM2.5 per city, on the scale used by IQAir's World Air Quality Report and the WHO ambient air database. The WHO annual guideline is 5 µg/m³ — about 0.23 cigarettes a day. Only 14% of measured cities met it in 2025.
What it misses
Tobacco smoke carries carcinogens city air mostly doesn't, and a smoker's dose comes in minutes, not hours. Averages also hide winter spikes: Delhi in November runs several times its yearly mean. Treat this as a sense of scale, not a diagnosis.
Corrections
Figures are rounded and some cities are represented by their nearest monitored station. If you have better data for a city, send it — the number matters more than the ranking.