Warning — the air in 154 cities, measured in cigarettes
← Full ranking
The Cigarette Index · 2025

Press kit

Everything a journalist needs: the headline numbers, the method on one page, and quotable lines per country. Free to use with a link to thecigaretteindex.com.

Ready-to-use lines

How the number is made

cigarettes per day = annual mean PM2.5 (µg/m³) ÷ 22

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.

Babies and children

Kids breathe far more air for their size. Per kilo of body weight, a baby inhales about 3× and a school-age child about 2× what an adult does (US EPA Exposure Factors Handbook). The baby and child numbers apply that factor.

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.

Request data or an interview

Leave your work email. We reply within a day.