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This Sound Sculpture Turns Oakland’s Air Pollution into Bells

Exploratorium artist-in-residence Rosten Woo wants you to hear the stuff you can’t see.


For hundreds of years, bells have been part of the fabric of life in cites. They chime the hour, celebrate marriages, and mourn deaths. And now, bells throughout Oakland will toll for something new: air pollution.

Mutual Air, a new exhibition by the Exploratorium’s artist-in-residence, Rosten Woo, uses sound to draw attention to Oakland’s chronic problem with air quality. The piece involves 30 sculptures composed of sensors that measure particulate matter in the air, a metal chime that rings in response, and a wooden block that sounds to indicate global carbon dioxide levels. The first bell was unveiled at the Oakland Museum on Sunday, with others to be installed in a to-be-determined network of homes, businesses, and places of worship over the next few months. The sound sculptures are accompanied by a series of short films on view at the Exploratorium that explore different aspects of gathering air quality data.

It's no secret that air quality varies widely in Oakland, especially in West Oakland, with pollution coming from the port, industrial areas, and all the diesel-powered trucks that travel through. The sensors in Woo’s sculptures measure fine particle pollution—that is, particulate matter with a diameter equal to or less than 2.5 micrometers, a threshold that has been linked to conditions such as asthma, heart disease, and lung disease. The more frequently the bell rings, the higher the particulate matter in the air. “It’s a no-brainer in terms of public health,” Woo says. “It’s also something that is fairly easy to measure with inexpensive equipment.”

The artist was inspired by UC Berkeley’s BEACON project, which blankets areas around Oakland and the wider Bay Area with small sensors to measure carbon dioxide. Woo also drew on a book called Village Bells, about the auditory soundscape of 17th-century France. “The bells would tell people literally when they entered the village, they tell you when to go to work, when to come back from the field, when someone gets married, when someone dies,” Woo says. “All these functions sort of set the rhythms of someone’s life but they’re never a focal point, they’re always a background part of the environment.” As the remaining 29 sound sculptures are installed over the coming months, Woo hopes that they will serve as gentle reminders—as bells long have in civic life—of the importance of the air we breathe. 


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