The old real estate mantra, “Location, location, location”, also applies to the quality of your air, and for some of the same reasons. Data provided by detailed regional mapping studies shows that the income level, home ownership patterns, and racial diversity of a neighborhood can indicate how healthy the air will be, since racial discrimination has led to poorer air quality in communities of color. These patterns can vary at the neighborhood scale. A new resource*,, allows Bay Area residents to look block by block at levels of five major air pollutants and greenhouse gases – nitrogen dioxide (NO2), carbon monoxide, ozone, carbon dioxide.and fine particulate matter – and also see the resulting regional patterns of good and bad air quality.

The interactive website, available in English and Spanish, was created to display data from a regional mapping project, partially funded by the Bay Area Air Quality Management District, which was done over several years using Aclima’s specially equipped monitoring cars and cloud-based data analytics platform.  The vehicles drove specified routes and gathered data. For the Bay Area project, the vehicles covered the entire 5,000 square mile region and drove every street 20 or more times over the course of a year, round the clock, under different conditions of weather and traffic.

Melissa Lunden, chief scientist at Aclima, said, “Mapping means that we can start to put numbers on pollution that other sources indicated was there.” For example, the highest NO2 in San Francisco is in the Financial District extending south to the freeways in the Mission. As Lunden commented, “If you’ve ever been in the Financial District during rush hour, this isn’t a surprise.”

The process started in 2015 with an intensive look at the West Oakland area before moving to the entire region. Aclima is continuing to collect data.  “We continue to refine and learn,” Lunden said, “and now we have the metrics to see when something changes.”

For many years, stationary air monitors were the only way to evaluate air quality. The Bay Area Air Quality Management District maintains a network of 31 stationary monitors,  but while Aclima’s data agrees with these monitors, they only show part of the picture. Lunden reported that the farther Aclima monitoring vehicles traveled from a stationary monitor, the more discrepancy was seen in the results.

The new data showed that the stationary air monitors can miss local pockets where air quality may be poorer. These are often areas where residents are unaware of household air monitoring devices or unable to afford them, and are therefore unable to gauge the exposures they are experiencing. The extremely granular nature of the Aclima information allows people using the website to evaluate average levels of the five pollutants in the specific areas where they spend time. As Lunden suggested, “People can make decisions about where they want to live, work or send their kids to school.”

Detailed hyperlocal data also allows better analysis of patterns of environmental impact on different communities. Overlaying this data with information about income and race, as Aclima has done in a partnership with Urban Footprint, provides insight into the contribution of these other factors to neighborhoods where pollution is worst.

Aclima and Urban Footprint produced a report in August 2022 with samples of their analyses showing the discrepancies in pollution exposure. It shows that racial distribution and socioeconomic status can be as predictive of bad air quality as a location near industry or a freeway, or interact with the other influences. For example, renters, regardless of race, have higher exposures to pollution throughout the region, and the same is true for those living significantly below the federal poverty line.

Lunden explained that Aclima makes its data available through its Aclima Pro subscription software for agencies and local jurisdictions, “to let them dig into the data and work with it.” Urban Footprint also provides extensive databases which can be integrated to assist government agencies, financial services, and utilities with decisions about resources, risks, demographics, and infrastructure needs.

Lunden is interested in discussing the potential uses of Aclima’s data with cities working on plans involving air pollution or climate change. Data from an intensive study and report has already been provided to some of the overburdened communities doing localized air quality plans, including West Oakland and Richmond.

The interactive map at is still a work in progress*. Aclima is in the process of verifying that it is accurately showing the extensive data from the monitoring vehicles. Because the map shows annual averages, Aclima is also considering how to show multiple years of data from the ongoing project. Lunden noted that data from 2019 to 2020 was affected by the drop in traffic at the start of the pandemic, so the ability to compare year over year might be useful for further research.

Additional Aclima mapping in the state and around the country may allow comparisons between Bay Area results and patterns in other areas, and could impact environment justice decisions such as additional funding for heavily burdened neighborhoods. Meanwhile, local residents have an additional tool to understand their personal environmental risks based on where they live and work.

*Note: The interactive map has a lot of information, so be patient while it loads!