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GreenSpace: Park bench will monitor air pollution

Of all the oddball things, Ben Franklin clearly had never seen the like: a park bench that monitors air pollution, powered by wind and solar.

A new bench at Independence National Historical Park monitors pollution.
A new bench at Independence National Historical Park monitors pollution.Read moreEnvironmental Protection Agency

Of all the oddball things, Ben Franklin clearly had never seen the like: a park bench that monitors air pollution, powered by wind and solar.

Philadelphia's venerated statesman (along with officials from the city, the U.S. Environmental Protection Agency, and others) unveiled the bench on Tuesday at Independence National Historical Park, its new home.

There, the bench will continuously monitor levels of ozone and particulate matter and post the results, er, bench-side, plus stream them online.

This amazing bench also monitors and streams weather conditions, including wind speed and direction, temperature, and relative humidity - all of which affect air quality.

Philadelphia is one of five cities to get a bench as part of a national pilot, the Village Green Project. Officials chose Independence National Park because it's a high-traffic area, meaning lots of pedestrians and vehicles. Plus, the Park Service patrols the area regularly, which minimizes the risk of vandalism.

Official air-quality monitoring data from any of seven city monitoring sites are already posted at But the bench is a whole lot more fun. Explore its data at

"I think it's really cool," said Shawn M. Garvin, the EPA's regional administrator. "If it was just kind of a metal contraption sitting off to the side, it wouldn't necessarily get the same amount of people interacting with it."

One potential flaw I noted is that the bench does not include information about health standards. If the bench registers ozone levels of 27 parts per billion, as it did Wednesday afternoon, is that good or bad? (Good.)

Perhaps that level of detail - and a level of accuracy equal to that for compliance purposes - is too much to ask of a bench. Perhaps it's enough that it simply draws attention to air pollution and how it changes over time.

Plus, air-quality standards involve averaging over time - eight hours, 24 hours, or annually, depending on the pollutant, noted Alison Riley, voluntary programs coordinator for Air Management Services, Philadelphia's air-pollution control agency, a Village Green partner. So even a spike "does not mean that the average air quality for the day will exceed the standard," she said.

Ozone, which forms when heat and sunlight essentially bake fossil-fuel pollutants, irritates the airways, exacerbating asthma and other lung diseases. Particulates are the tiniest bits of air pollution, capable of lodging deep in the lungs and aggravating heart and lung disease.

For a daily regional air-quality forecast, along with more information about levels of particulates and ozone, go to It ranks days according to whether the air quality is good, moderate, unhealthy for members of sensitive groups, or unhealthy overall.

To Joseph O. Minott, executive director of the Clean Air Council, a Philadelphia nonprofit science and advocacy group, the new bench is important in a broader context: the democratization of air monitoring. No longer do we have to rely solely on the government (with its limited resources), or industry (with its limited credibility), to tell us about our air.

The technology has advanced so much, and become so much less expensive, Minott said, that "it's possible to build a pretty accurate monitor for a couple hundred bucks that residents can use themselves."

Monitoring in general is expanding, he said. Large, sophisticated government monitors do a great job, perhaps, at determining what was happening on a regional scale. But now, ordinary people are able to monitor the air at a refinery fence line, or along a busy stretch of interstate.

"It used to be that the governing agencies had these very sophisticated air monitors placed wherever it made sense," Minott said, like near the center of Philadelphia. "But it was hard for people to connect to that. It would say that the air quality was fine, but in their particular community - Port Richmond, for instance - they knew it wasn't. They could smell it."

The Clean Air Council recently bought components for about $200, built a monitor, and is having it calibrated in a lab. Minott expects field tests to begin in two months or so. The goal is to deploy it in Pennsylvania's shale fields and communities with environmental justice issues.

The EPA is championing this new generation of monitors, working with industry, academics, and others to further develop the means to monitor air quality, even down to the personal level.

In 2013, the EPA, the National Institutes of Health, and other agencies held a "My Air, My Health Challenge" for innovators. The $100,000 winner: a team that came up with a wearable sensor and microcomputer that factors in airborne particulates and the person's breathing rate to compute an overall pollution exposure that can be streamed to any Bluetooth-enabled device.

In March, a Pittsburgh company, AirViz Inc., a spinoff of Carnegie Mellon University, released its own personal air-pollution monitor, the Speck. It measures particulate levels, and a display screen shows instantly if the air becomes unhealthy. The idea is that the user could then close a window, say, or install an air filter or alter outdoor activities.

The alarm-clock-size device is available for $200 at, and about 300 are already in use in Pittsburgh. The Heinz Endowments and Pittsburgh Foundation have paid for 1,000 Specks to be lent through public libraries, schools, and citizen groups.

So perhaps Independence National Park is the perfect place for Philadelphia's bench for another reason. Here, we - the bench seats three, four if you're friendly - can take a more personal view, declaring a sort of monitoring independence.