Explore the Bay Area Monitor

October/November 2014

A New Sensation

By Alec MacDonald

Are you careful about what you put in your body? Do you buy organic fruits and vegetables to avoid pesticide exposure? Do you own a reusable water bottle marketed on a claim it won’t leach harmful chemicals?

With food and drink, consulting a label may help you identify safer options, but the one substance you consume the most bears no handy list of ingredients. The air you inhale comes without reassuring tags or packaging to tell you what might be entering your lungs.

However, if you’re feeling particularly vigilant — or just curious — you could try testing the air yourself. Sensor technology has progressed to the point where motivated individuals can assess the atmosphere around them, to a limited degree. Most readily obtainable instruments won’t provide readings of the greatest accuracy, but sometimes they prove more trustworthy than the advertising attached to the other things we ingest.

Do-it-yourself air monitoring may sound fanciful, but the practice has begun to show real viability. Equipment options have proliferated thanks to the international emergence of the so-called maker movement, a groundswell of grassroots manufacturing generated by a motley collection of engineers, designers, hobbyists, and inventors. “There’s this increasing circulation of expertise available, especially online, where you can now go and learn how to assemble and program, as well as purchase, the hardware that you need,” attested David Holstius, a senior scientist at the Bay Area Air Quality Management District. “That sort of expertise was not available five or certainly ten years ago.”

Taking advantage of this phenomenon himself, Holstius conducted research with low-cost sensors as a part of his recently completed doctorate in environmental health sciences at UC Berkeley. He and his colleagues measured fine particulate matter concentrations in West Oakland using custom devices made with $10 sensors and less than $200 worth of additional hardware. In results published last April by the international scientific journal Atmospheric Measurement Techniques, these devices gathered data that reasonably correlated with data from both official regulatory monitors as well as industrial-strength commercial equipment.

“That’s a finding that needs to be taken with a grain of salt, because all we did was show that it worked in one place, at one time,” Holstius conceded. “But it does open up the question of, ‘Where else would it work, and under what conditions, and what would that be useful in telling us?’”

For air quality regulators, inexpensive devices could fill gaps in between their more sophisticated monitoring stations, which boast vastly superior performance but cannot be deployed so extensively due to budgetary constraints. Integrating cheaper alternatives to create a denser monitoring network could yield a more comprehensive picture of air quality landscapes.

As Holstius emphasized, though, this possibility remains highly theoretical and full of pitfalls. Low-cost sensors have plenty of shortcomings to take into account. For example, those that measure particulate matter concentrations have no way to gauge toxicity, meaning they can’t tell the difference between microscopic sea spray droplets and carcinogenic diesel soot. And obviously, durability represents significant concerns with respect to such bargain-priced electronics. Gathering data that correlates with conventional monitoring methods, however, continues to loom as the biggest stumbling block for regulatory authorities. To this point, Barry Wallerstein, executive officer of the South Coast Air Quality Management District in Southern California, cautioned his board in a July 11 memo that “poor quality data obtained from unreliable sensors, especially that in conflict with data obtained from traditional, more sophisticated monitoring networks, may not only lead to confusion but may also jeopardize the successful evolution of the ‘low-cost’ sensor technology.”

To introduce some authoritative scrutiny over this nascent field, Wallerstein’s board subsequently approved $852,000 to establish a testing center for evaluating such technology at the district’s headquarters in Diamond Bar. Coincidentally, the board’s allocation came just days after the Environmental Protection Agency unveiled a national grant program to fund research on “empowering communities and individuals to take action to avoid air pollution exposure using low-cost portable air pollution sensors,” according to an official announcement. In the next several months, the agency intends to award a cumulative $4.5 million to some half dozen organizations with the best proposals. Holstius said the EPA initiative should cultivate some exciting collaborations between professionals in the field of air quality monitoring, participants in the maker movement, and average folks seeking to better understand the world around them.

With the aim of sparking one of these collaborations here in the Bay Area, engineer Peter Sand hopes to procure a share of the EPA funding for Manylabs, an educational nonprofit he founded in San Francisco’s Mission District. “We’re mostly focused on awareness of the process of scientific inquiry,” Sand explained about the organization’s purpose. “The idea is that by giving people tools and experience with collecting their own data, analyzing that data, then they can go off and work on the environmental and political issues that they want to, using those tools.”

Manylabs has an impressive toolshed, so to speak; it supplies teachers and tinkerers with a range of kits and components for experimentation in biology, chemistry, physics, math, and computation. As well as featuring sensors for measuring air quality, the organization offers ones to evaluate things like water, light, and electricity. In application to the EPA grant program, Sand is proposing to monitor particulate matter and carbon monoxide around Oakland, recruiting local groups to operate portable devices that Manylabs has under development.

A precursor to these devices has already seen duty in the East Bay, as teenagers at Richmond High School had the chance last April to try out equipment furnished by Manylabs. Students in biomedical sciences and chemistry courses took air quality readings in and around their school with the guidance of EarthTeam, a Berkeley-based nonprofit that encourages youth to embrace sustainability and environmental stewardship. In a series of class visits, the organization covered investigative methodology and results interpretation, but in an especially pertinent way. Describing the project, EarthTeam Program Manager Doug Streblow said, “It takes the textbook chapter about air quality … and turns it into real-life, tangible, multisensory exploration.” He pointed out that students worked with “data that affects them on a daily basis … particularly in Richmond, where they’re in a community that’s very affected by Chevron, by the oil refinery.”

Even in places without enormously conspicuous pollution sources nearby, however, inquisitive individuals still have good reason to take inventory of their surroundings. Air quality monitoring can reveal a wealth of valuable information. Like Sand observed, “As we’re walking down the sidewalk, we’re walking through a whole bunch of data. And normally that’s invisible, but sensors let you make that visible, they let you turn all of those hidden numbers into real numbers you can see.” Bringing data to light, depending on what you discover, could unnerve you a little, but at least you’ll have a notion of what you might be breathing — and that’s a key first step toward addressing a potential risk. As Sand noted, “By measuring those numbers, you can start to make models with the numbers, and you can start to learn about how you might solve problems in your community.”

Alec MacDonald is the editor of the Bay Area Monitor.

October/November 2014

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