If you live in a city, air pollution is so bad you might as well be smoking

You’ve probably heard about the heavy layers of smog that hang over major metropolitan areas such as Beijing and Los Angeles. But it’s difficult to imagine the damage of something you can’t really see, such as air pollution. Well, it turns out that walking through a smog-infused city can be just as bad for your health as smoking cigarettes can be.

Shit, I Smoke! is an app designed by digital developers Marcelo Coelho and Amaury Martiny that translates the amount of pollution in your city into the number of cigarettes that could theoretically cause the equivalent amount of damage. Taking real-time pollution data from actual air quality stations around the world, the app uses the city’s PM2.5 number (a microscopic particle that is present in greater quantities in polluted cities) to produce a cigarette count. The free app is available in the App Store and through Google Play.

Coelho and Martiny were inspired to create the app after reading an article co-authored by Richard Mueller, a physics professor at the University of California, Berkeley. The article analyzes the similarities between smoking-related deaths and the effects of being exposed to high levels of PM2.5. According to the study, “Here is the rule of thumb: one cigarette per day is the rough equivalent of a PM2.5 level of 22 μg/m3 (…) Of course, unlike cigarette smoking, the pollution reaches every age group.” The study goes on to conclude that Beijing’s PM2.5 level equates to smoking four cigarettes per day, while Los Angeles County’s pollution levels are equivalent to half a cigarette a day — better than Beijing, but still harmful to human health.

Martiny has personal experience living in a polluted city, having resided in Beijing during the years leading up to the 2008 Olympic Games.  “I personally saw a huge transformation of the city,” Martiny said. “In the beginning, I could see big blue skies, and there were not so many cars. It was quite pleasant,” he told CityLab. Martiny said that the air quality took a turn for the worse when Beijing’s rapid industrialization saw coal-burning plants begin spewing pollutants into the air more aggressively than before.

“The city changed its face, right before I decided to leave. It was really not livable; the air was horrible to breathe, and I just couldn’t stand to live there any longer,” Martiny said.

According to Martiny and Coelho’s app, a resident in Paris may end up smoking anywhere between three to six cigarettes in a single day — or at least, encounter pollution that produces the same level of damage. In Mexico City, people could be smoking as many as 6.5 cigarettes a day, while in Delhi, that quantity is 20 cigarettes, a staggering number.

Coelho and Martiny hope their app will awaken people around the world to the realities of air pollution.

“These air-quality monitoring stations are just numbers, numbers that are very specific to professionals who work in environmental issues,” Martiny said. “So when you make this conversion to cigarettes, it makes it easier to understand what people are dealing with and the consequences air quality has in their daily lives.”