Googling Air Quality, One Block at a Time
Finding out local air quality could be as simple as searching for an address — and it could use the same fleet of vehicles that maps your neighborhood.
Google Earth Outreach teamed up with nonprofit Environmental Defense Fund to map changes in air pollution across the streets of Oakland, Calif., home to one of the nation’s busiest ports and related freight traffic. The results could change how local air pollution regulators and communities track and address air pollution.
Between 2015 and 2016, Google Street View cars — outfitted with mobile sensors developed by San Francisco-based Aclima Inc. — prowled the streets of Oakland’s low-income neighborhoods, sniffing out air pollution levels across blocks.
The yearlong pilot resulted in “hyperlocal” interactive maps of East and West Oakland, showing air pollution concentrations at the street level in neighborhoods that had particularly unhealthy levels.
Though still in its infancy, mobile monitoring could provide local regulators with reams of new data on pollution hot spots, particularly in low-income and minority communities that bear the brunt of contamination. Regulators in turn could use this data, for instance, to heighten enforcement of environmental laws, and possibly tighten Clean Air Act permit limits for industries in these neighborhoods.
The data from Oakland show its three stationary air quality monitors perched atop buildings weren’t capturing the concentrations of nitrogen oxides and black carbon — pollutants caused by burning fuels — that people at street level were breathing, Ananya Roy, an environmental epidemiologist with the Environmental Defense Fund, told Bloomberg Environment.
The West Oakland Environmental Indicators Project, a community advocacy group, wants to use the evidence it gathered about pollution hot spots to work with state and local officials to clean up those areas as required under California law, project co-founder Margaret Gordon said.
Wheels on the Ground
Houston undertook a similar mobile monitoring project, while London is in the midst of one. The challenge now for researchers is whether they can replicate their findings in larger urban areas where a variety of industries abut low-income neighborhoods, according to Roy.
“It’s a revolutionary idea to equip Street View cars that already are out there mapping streets to map air quality as well,” said Karin Tuxen-Bettman, program manager for Google Earth Outreach.
Earlier this year Google Earth Outreach partnered with the environmental group to map methane leaks from buried gas pipelines in major cities across the country.
“This is one more way we can empower the public to understand the quality of the air in the communities where they live and work,” Tuxen-Bettman told Bloomberg Environment.
Going forward, the Environmental Defense Fund wants to test the viability of low-cost mobile sensors, Aileen Nowlan, the group’s senior manager for business innovation, told Bloomberg Environment.
The Google Street View cars are now on loan for the pilot project, but the monitors could be attached to government or utility fleets that are constantly driving local streets.
Houston volunteered the cars used by their on-call public health workers tasked with responding to various environmental health concerns, Loren Raun, the city’s chief environmental scientist, told Bloomberg Environment.
Pumping the Brakes
Car-mounted monitors show promise, but they might not provide a complete portrait of a region’s air pollution, James Roberts, an atmospheric scientist at the National Oceanic and Atmospheric Administration’s Earth System Research Laboratory in Boulder, Colo., said.
“If you are using mobile labs, you have to drive them all the time to get the same level of accuracy,” said Roberts who was involved in an Environmental Protection Agency effort to assess low-cost sensors that citizens used to track pollution from wildfires.
The California Air Resources Board told Bloomberg Environment that it considers mobile sensors among the tools neighborhoods can use to gather air quality data, but it hasn’t decided to roll them out statewide yet.
The Street View cars collected more than 3 million data points and logged more than 15,000 miles driving through Oakland neighborhoods, said Joshua Apte, an assistant professor of engineering at the University of Texas at Austin who led the monitoring project. Each city block was sampled on an average of 31 different days throughout the year.
Apte acknowledged that unlike fixed monitors, they didn’t get a 24-hour picture of air pollution levels in Oakland, but the data they received was far more detailed.
Kicking Into High Gear
Where fixed monitors are able to capture pollution levels on an hourly basis, mobile sensors collect data every second as cars continuously drive throughout neighborhoods, researchers told Bloomberg Environment.
Houston views mobile monitoring as “a real game changer” as it sifts through its monitoring data, Raun said. Without zoning requirements, Houston’s residential neighborhoods are often interspersed with industrial sites and stationary monitors at pollution sources may not capture what residents breathe, Raun said.
“We want to find out whether there is a change in air pollution within a block as was seen in Oakland or does the change in pollution levels span further than a block,” Raun said.