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With 'Mutual Air,' this California artist leverages the sounds of science


Notice: Transcripts are machine and human generated and lightly edited for accuracy. They may contain errors.

Judy Woodruff: Now a look at a unique way to measure air pollution.

Jeffrey Brown traveled to the San Francisco Bay Area to meet an artist who is bringing sound to a usually silent problem.

It is part of our regular series covering arts and culture, Canvas. (

Jeffrey Brown: The ring is simple, familiar, pleasant.

These bells look and sound just like wind chimes, but they're not controlled by the wind at all. This is Mutual Air, a sound installation in the Bay Area that measures air pollution.

Rosten Woo: It's the most shared resource in the world, in a sense. You can't help but share it.

Jeffrey Brown: Rosten Woo is a California-based artist and designer who's currently an artist-in-residence at San Francisco's Exploratorium.

Celebrating its 50th anniversary this year, the museum has placed a heavy emphasis on climate science and environmental issues. Woo came up with his Mutual Air project as a way to make measurements and data about the air we breathe more accessible.

Rosten Woo: What I tried to do is kind of give a public presence to the air.

Jeffrey Brown: A public presence to the air?

Rosten Woo: Yes.

Jeffrey Brown: Meaning what?

Rosten Woo: Well, I mean, the great cliche about air, right, is that, you know, you can't experience it because it's so ever-present. It's always around.

Jeffrey Brown: We're always experiencing it.

Rosten Woo: Yes. But we don't ever have like a very direct indicator of kind of the dynamic nature of the changes in that air.

Jeffrey Brown: The device uses a laser sensor to detect particles in the air. It picks up particulate matter that's 2.5 microns wide, known as PM-2.5, about one-30th the width of a human hair.

But, at that size, scientists say, particles can worsen conditions like asthma, lung and heart disease. The bell, sensing a high level of particulate matter, releases a magnetic mallet that strikes the metal pipes surrounding it.

Rosten Woo: You really can think of it as, like, wind chimes for air pollution. So, when it's going all of the time...

Jeffrey Brown: Wind chimes for air pollution?

Rosten Woo: Yes.


Rosten Woo: So, when it's going off a lot, as you might, on a very windy day, you would have a sense, like, OK, this is, this is getting up into maybe a not particularly great or healthy level of PM-2.5.

Jeffrey Brown: These are beautiful sounds. You even made it musical, right, with the different levels of pipe.

Rosten Woo: Yes.

Jeffrey Brown: Why? Why, if it's supposed to be kind of a -- I don't know, a warning?

Rosten Woo: We wanted to be in this kind of nether-space between, like, if you heard it a little bit, it wouldn't bother you. You don't feel like someone's, like, poking you.

But if you hear it a lot, you know, it actually does become kind of annoying, in the same way that a wind chime becomes annoying a lot.

There is one chime that's a little further out, so it's struck less frequently. But when it's very active, you hit this kind of slightly more discordant note. So, as it kind of gets into more dangerous registers of particles, you know, it becomes a little eerier in its tone and cast.

Jeffrey Brown: The Bay Area, Oakland in particular, has some of the lowest air quality in the nation, giant ports, train tracks, crisscrossing interstates. Woo and the Exploratorium have begun to install bells around the city. They plan to have 30 up in all.

Rosten Woo: My hope is that it has a very subtle and slow effect, that people will kind of become aware of these. Eventually, they become curious enough to read the sign, and kind of understand what it is, and then thereafter think about what that means and start thinking like, oh, why is this chime going off now in this neighborhood?

Jeffrey Brown: Late last year, just weeks after the installation of Mutual Air began, the deadliest wildfires in California history swept through the northern part of the state. The bells went off constantly.

Rosten Woo: It was this time when this issue that is often kind of very localized, suddenly, like this much broader swathe of people cared about it.

So the hope is maybe this project can kind of extend that moment of interest.

Jeffrey Brown: One site is the West Oakland Environmental Indicators Project, an environmental justice organization that gathers its own data on air quality.

Margaret Gordon is the director. For her, Mutual Air adds another tool.

Margaret Gordon: By having this data, we're able to pinpoint to the city, the state, the county where they need to advocate to do more emission-reduction planning, such as making the port go totally electrified, bring electrified trains, the cranes, the trucks.

So those are the type of things, having that data, we're able to campaign and advocate for it.

Jeffrey Brown: I asked Rosten Woo where the art comes in and meets advocacy.

Rosten Woo: I think it kind of falls into the catchment of art, because it doesn't fit very neatly into other categories. It's not strictly a public health program. It's not strictly a political project.

Jeffrey Brown: But is it a political act in some ways?

Rosten Woo: I don't want to oversell it and say, like, you know, this is real political action.

I think having an awareness and a new knowledge of how your urban environment is shaped does engender politics, does kind of lead you then to have questions about, like, well, why is this so?

Jeffrey Brown: For the "PBS NewsHour," I'm Jeffrey Brown in the San Francisco Bay Area.

Judy Woodruff: Fascinating.

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