Here’s why researchers say breathing San Francisco air today is like smoking 11 cigarettes

SF Gate

Breathing the smoke-filled air in San Francisco today is equivalent to smoking more than a half-pack of cigarettes, researchers say.

San Francisco’s air quality on Friday registered “very unhealthy” levels of particulate matter, following public health warnings and mass closures of schools, universities and businesses. As of Friday at 11 a.m., the Air Quality Index (AQI) for San Francisco read 246, a measurement that indicates the concentration of particulate matter less than 2.5 micrometers in diameter (PM2.5) in the air over a period of time.  

An AQI index figure above 151 is considered unhealthy.

To help people better grasp the level of danger the smoky air poses, researchers at UC Berkeley, devised an equation that translates AQI into the rough number of cigarettes one would have smoked just by breathing the polluted air. One cigarette per day is the rough equivalent to a PM2.5 level of  22 μg/m3, the researchers explain in their study.

In layman’s terms, this means that if the AQI registers at 22, the amount of toxic air particles you inhale throughout the day would be equivalent to smoking a single cigarette.

With San Francisco registering an AQI of 246, breathing the noxious air for 24 hours is equivalent to smoking about 11 cigarettes — or a little over half of a pack.

Average air pollution in the United States is equivalent to the smoke from .41 cigarettes per day, the researchers calculated.

https://m.sfgate.com/california-wildfires/article/air-cigarettes-smoke-breathing-aqi-unhealthy-13399240.php