AQI Detail Page
AQI 120: cigarette equivalent, interpretation, and what to do next
At AQI 120, a full day of exposure is roughly equivalent to smoking 2.2 cigarettes.
AQI category
Unhealthy for Sensitive Groups
PM2.5 estimate
48.3
µg/m³
Daily equivalent
2.2
cigarettes / 24h
If repeated daily
66
cigarettes / 30 days
What AQI 120 means
Longer outdoor exposure can meaningfully increase dose, especially for sensitive groups.
Children, older adults, pregnant people, and anyone with heart or lung conditions should reduce time outside and avoid hard exertion.
Exposure framing
1 hour: about 0.09 cigarettes.
2 hours: about 0.18 cigarettes.
24 hours: about 2.2 cigarettes.
7 repeated days: about 15.4 cigarettes.
Scenario guidance at AQI 120
These are the kinds of day-to-day decisions users commonly make from this reading.
Commute or errands
Use caution2 hours equals 0.18 cigarettes at AQI 120.
Limit extra walking time and keep a mask ready for transit platforms or traffic corridors.
Outdoor exercise
Move indoors1 hour equals 0.09 cigarettes at AQI 120.
Take the workout indoors. Heavy breathing raises inhaled dose quickly.
Kids, school, or playground time
Move indoors3 hours equals 0.27 cigarettes at AQI 120.
Shift recess, pickup waiting, and playtime indoors when possible.
Sleeping with windows open
Move indoors8 hours equals 0.73 cigarettes at AQI 120.
Keep windows shut and rely on filtered indoor air.
Why the estimate is credible
The site first converts AQI into an estimated PM2.5 concentration and then applies Berkeley Earth's cigarette-equivalence framing.
The estimate is most useful for comparing air-quality dose across times, situations, and repeated days. It should not be treated as a literal smoking-equivalence medical claim.
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