Wearable sensors drive demand for cleaner air
As worldwide calls for urgent action on air pollution grow, crowd-sourced data (and the ambitions of a precocious eight-year-old) will play a critical role
Most Fridays, my eight-year-old son and I take a walk. Our route takes us across some of the busiest traffic intersections in Brooklyn. As we walk, we talk. My son has lots to say and he bounces from topic to topic in funny and unexpected ways. This being New York, we often have to shout over the sound of car horns, sirens and buses roaring away from curbs.
Earlier this year, our conversation centered around the little white gadget clipped to my bag. Known as an AirBeam, it was personal air quality monitor, able to sense and measure the pollution in the air around us as we walked. The data it gathered was fed, via Bluetooth, to an app on my phone, giving us real time information about what was in the air we were breathing. What we saw was sobering.
With increasing global concern about air pollution, the availability of, and interest in, wearable air quality monitors has accelerated in recent years. In addition to the AirBeam, there is now also the Tzoa, the Flow, the ATMOtube, the CleanSpace Tag. A quick search of crowdfunding sites like Kickstarter and GoFundMe reveals multiple new monitors under development all claiming to give us the lowdown on what’s in the air around us.
Many of these gadgets stream their measurements straight to your smartphone. The AirBeam uses an open-source platform, AirCasting, and the information appears in ever evolving graphs which dip and peak as you move through space and time.
For most of mine and my son’s Friday walk, the lines remained reassuringly green and steady. But as we crossed a bridge above the Brooklyn-Queens Expressway, with traffic flying beneath our feet, the PM2.5 line (so-called because the particles detected are less than 2.5 micrometers in diameter, or one-thirtieth the size of a human hair) suddenly spiked and turned a traffic light red. We stood together and watched it silently for a few seconds.
“What does it mean?” my little boy asked.
I hesitated. The air around us looked clear, the sun shone, the people looked the same. Whatever was happening in the air above that expressway, New York (no surprise here!) didn’t seem to care. Staring at that red line, I realised I didn’t really know what it meant either. Could we stay and safely breathe that air? How long before it started to affect our health? A minute? A week? A year? I did that parent thing and answered without really answering.
“It means we’re moving on,” I tell him. “Let’s walk.”
We are entering an unprecedented era in air quality monitoring. Information is more freely available than ever before. In some parts of the world, there are now sophisticated systems that synchronise and map data from multiple sources to give real time, block-by-block analysis of entire neighborhoods. One project currently underway in London, is using data collected from monitors on lampposts, cars and carried by children as they journey to and from school, to attempt to map a whole city.
So what can we do with all this information?
On an individual level, just like my son and I at the BQE flyover, it gives us a choice to move on. Analysis of data gathered by mobile monitors mounted on Google Street View cars in Oakland, CA, has shown that air quality can vary by up to eight times in just one city block. Put that rich, location-specific data into the hands of users and suddenly we’ll have the power to make endless personal health- and lifestyle-related choices — when to go outside, which routes to travel to work, where to shop and recreate and, more profoundly, where to live and send our kids to school.
Aileen Nowlan is an expert on air pollution monitoring and a colleague of mine at Environmental Defense Fund.
“The holy grail when it comes to air quality analysis is being able to connect exposure to location,” she says. “Data from personal air quality monitors can give us the hyperlocal, detailed information that can pinpoint pollution sources and significantly enhance our decision-making.”
But not everyone has the desire — or the means — to move on and in any case, says Nowlan, that’s not really the point.
“Our goal should not be for people to buy their way to cleaner air,” she says. “It should be to catalyze change among companies, regulators and policy makers.” For example, data collected by individuals living near a goods distribution center could accelerate a company’s transition from diesel to electric trucks, or force a change in building codes to prevent onsite combustion. In France, pollution data collected by a citizen living near the port of Toulon, is already said to have played a part in the city’s decision to electrify the port, enabling ships to switch off diesel engines and plug-in to run operations while in port.
“It’s a powerful example of how hyperlocal insights can inspire champions, rally support for policy change, and give people a vision of the future,” says Nowlan.
Limitations remain. The market is currently largely unregulated meaning the quality of the data collected is variable and vulnerable to dispute. The key, says Nowlan, is independent validation. “We need an independent voice that says, ‘this sensor actually does what it says it can do’. We need more industry standards.”
From a user experience perspective, the tech also has a way to go. I found the AirBeam to be glitchy — dropping Bluetooth connection and unexpectedly ending monitoring sessions. The app invited constant manuel monitoring, information retrieval wasn’t intuitive and useful data analysis — for example the overlaying of the pollution data on a map — had to be done by analysts at EDF.
“In the future, information gathering will be more passive,” says Nowlan. “Insights about what’s impacting your health, when and where, will be delivered to you just as you go about your daily lives.”
She also points to the need for better access to information about the health implications of higher readings.
Since that walk over the BQE, I dug into what I was being told. PM2.5, I discovered, is a byproduct of burning and commonly comes from power plants, car exhaust and wildfires. Once in our lungs it can get deep into the tissue and even enter our blood streams. It is known to cause asthma and respiratory inflammation and to increase the risk of lung cancer, heart attack and stroke. In Oakland, CA, analysts compared block-by-block data of traffic-related air pollution with the electronic health records of 41,000 people, and found that for the elderly, differences in pollution exposure between neighbors, even those who live on the same street or within a few blocks of each other, impacts their risk of heart attack and death from heart disease. It also impacts cognitive abilities. In 2016, a study of the impact of air pollution on the New York Stock Exchange found that a PM2.5 increase of just one point, reduced same day returns by 11.9%.
Evidence that pins specific, localized pollution to specific and unwelcome outcomes, is a powerful catalyst for change. What if I could use the AirBeam data to advocate for the electrification of my kids’ school buses? Or to get the school to enforce a ‘no idling’ rule at pick up? What if experts could pull crowd-sourced pollution data from the cloud in response to specific circumstances — for example where city planners are seeking to set sensible emissions standards for a new development; or in a diagnostic setting when a patient presents to a doctor’s surgery with breathing difficulties. It’s a future that feels enticingly within reach.
My son was first hospitalized with breathing difficulties when he was four months old. I’ll never forget the noise his little body made as he fought for air — like the sound a wide-toothed hand saw being drawn back and forth through wood. That was the day I also learned that the surest visual indicator of a child’s respiratory distress lies in the extent to which the skin around the ribcage is sucked between the bones with each ragged attempt to breathe. When it’s really bad, the skin over the ribs appears ghost-like, translucent.
I wish I didn’t have to know this, but I do.
My family has been lucky. Since that first visit, my son has only been back to the emergency room once. Both times the treatment was quick and effective. Others are not so lucky. Particulate pollution is single-handedly responsible for up to 30,000 premature deaths in the U.S. each year. Two years ago, a child from his school — which sits above the BQE — died during an asthma attack. There are currently 6.2 million children in the U.S. with asthma. It accounts for 9.8 million doctors visits and 1.8 million trips to the emergency room each year.
As President Trump seeks to jettison the Clean Power Plan, roll back regulations limiting emissions from cars and undo the Mercury and Air Toxics Standards, reliable, affordable and independently validated air quality information will become ever more crucial.
Meanwhile, my son and I continue our Friday walk-and-talks. Recently we’ve seen an increase in the number of electric cars purring silently down the streets. He finds this very exciting. We speculate how long it will take for all the cars on the road to be electric and imagine how much cleaner the city will be then.
He is eight and ambitious. He believes he could design a car powered by solar. His bedroom floor is scattered with LEGO prototypes although he’s pretty sure he’ll need a factory to take his creations to scale.
Because I am a parent, I seize the opportunity to teach. It only makes sense to build cars if somebody wants to drive them, I tell him. People need to know that gas-powered cars are harmful, so they’ll start to demand cheaper, more cleanly-powered electric cars, I say. They need to know what gas-powered cars do to their health.
He can tell I’m building up to something but he’s already way ahead. “That’s why we need air quality monitors,” he says.