Pollution Meter Sounds Crowd-Sourced Alarm Over Filthy Air

Londoners were recently warned to keep their babies inside. Here's the app that offered the heads-up.

Before starting the day, most everyone checks the weather to see what to expect outside. But have you ever considered that you might want to look up the air quality as well?

An app called Air Report by Plume Labs based in Paris alerts users of air quality issues in their area. Currently the app is available in 350 urban centers around the world.

The app provides a readout of air pollution levels at your location, as well as UV and temperature information, and guides users on whether air quality levels are suitable for outdoor sports, family time or other activities. Air quality varies throughout the day, and users are able to view past and predicted pollution levels.

Recently, an air quality alert in London advised parents against spending too much time outside because of high levels of toxic pollutants in the air, according to the Evening Standard. "We are not saying that you should not go out with your baby," Plume chief executive officer Romain Lacombe said in a statement. "We are advising to avoid major roads and high traffic areas."

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So what exactly is the app measuring? The company monitors levels of nitrogen dioxide, ozone, sulfur dioxide and particulate matter. Instead of giving users a readout of level in parts per million, the app distills the information down into a Plume Index, which mirrors the U.S. Environmental Protection Agency (EPA) Air Quality Index. Pollution levels are given a simple score, ranging from 0 to 500, that correspond to different levels of health risk.

Air pollution is often the result of man-made sources, such as coal-fired power plants, gasoline-powered vehicles or industrial activities, but natural activity, such as dust storms, can also play a role in clouding air with pollution.

According to a report released earlier this year by the World Health Organization (WHO), 92 percent of the world's population lives in areas where air pollution levels exceed public health standards.

An estimated 6.5 million people, or 11.6 percent of all global deaths in 2012, were associated with indoor and outdoor air pollution. Ninety-four percent of these deaths were caused by noncommunicable diseases such as heart disease, stroke or lung cancer. Air pollution can be also responsible for non-fatal conditions, such as respiratory infections, and exacerbate health conditions like asthma. Women, children and the elderly are the most at risk.

Most deaths associated with air pollution occurred in low- and middle-income countries, typically in Southeast Asia and Western Pacific regions, according to the WHO. An interactive map available on the WHO's website shows levels of air pollution around the world.

Plume's Air Report is a no-cost, ad-free app available on iTunes and Android.