Mapping Street-Level and Real-Time Air Quality in West Oakland

6 min read
June 11 2020

Today, in collaboration with local community groups West Oakland Environmental Indicators Project (WOEIP) and Rising Sun Center for Opportunity, we are launching a freely available, interactive, online report of block-by-block air pollutant and greenhouse gas levels throughout West Oakland, representing 34 million data points measured over six months in the second half of 2019. Community members can look up hyperlocal air pollution by address — where they live, work, play, and learn — share on social media, and access resources to take action.

Since 2015, we have been measuring hyperlocal air quality in West Oakland, which is situated between freeways and one of the largest ports in the U.S. West Oakland is an environmental justice area whose residents have been disproportionately impacted by air pollution for decades, with higher rates of related health concerns that reduce quality of life and shorten average life spans compared with people in neighboring communities.

In 2017, the peer-reviewed journal Environmental Science & Technology published the discovery that air pollution can persistently vary by up to 8x from one end of a block to another, based on our work together with scientific researchers, WOEIP and community leaders measuring air pollution block by block in West Oakland.

For the first time today, we are also launching real-time data from stationary air monitors installed throughout West Oakland earlier this year.

New Real-Time Air Pollution Data Sharing

Our stationary monitors continuously measure and report current pollutant levels at six locations throughout West Oakland. In addition to revealing current air pollutant levels near community members around the clock, aggregated measurements from these stationary monitors give a detailed picture of how air pollutant levels are changing over time at their location. With this new section of the West Oakland Insights interactive air quality report, people can view current pollutant levels at the stationary monitor nearest to their address, and see pollutant levels in 24-hour, 1 week, 1 month, and 90 day windows.

We built this real-time air pollution data resource in collaboration with WOEIP, Rising Sun, and the broader community. We are very grateful to the community members who allowed us to install stationary monitors at their locations, including Saint Vincent’s Day Home, Mutual Express Company, West Side Missionary Baptist Church, and Old Kan Beer & Co., as well as private residences.

Key Features of the West Oakland Air Insights Interactive Report

Entering an address in the search bar at the top of the page takes you to a hyperlocal map of street-level air pollution data. With the drop down menus you can switch the seasonal measurement time period from summer 2019 ( July to Sept) to fall 2019 (Oct to Dec 2019), and search by pollutant measured from PM 2.5 (fine particulate matter) to ozone, carbon monoxide, carbon dioxide, nitric oxide, or nitrogen dioxide. The street-level air pollution data shows the selected pollutant levels at the specific block of the entered address, averaged over the season selected. On the map, light green signifies relatively lower average pollutant levels, and dark red signifies relatively higher average pollutant levels.

Beneath the street-level map there is a description of the common sources and their health impacts, as well as the numerical value for the seasonal average, for the selected pollutant. For PM 2.5 for example, you can also see whether the seasonal average pollutant level was above or below the annual WHO Air Quality Guideline Values (10μ/m3) and the EPA National Ambient Air Quality Standards (12μ/m3).

Scrolling down, the next section in the interactive report shows real-time air pollution data. Here you can see measurements of fine particulate matter (PM 2.5) from the Aclima stationary monitor closest to the entered address. You can switch from Current conditions to average levels over 24-hours, 1 week, 1 month or 90 Days. A graph beneath that shows the fluctuations in the pollutant levels over the time period selected. If an address is not entered, the default is the West Oakland BART station.

Notable Trends in West Oakland Hyperlocal Air Pollutant Levels

In fall, we noted a few meaningful trends which are pinpointed in the Notable Locations map. There were elevated levels of nitrogen dioxide at multiple locations across West Oakland, including parts of the Lower Bottoms neighborhood, and the industrial area located near Peralta and Mandela Parkway. It is highly likely that elevated NO₂ at each location is related to nearby transportation sources, with diesel trucks being of particular concern. The Lower Bottoms neighborhood is located near a main thoroughfare across the southern part of town and the industrial area has a concrete facility. The Peralta industrial area and blocks near the West Oakland Health Council also had relatively high levels of PM2.5.

When comparing PM2.5 levels across West Oakland between summer and fall, we saw a modest decrease on average. At the hyperlocal level, some areas saw a slight decrease while others showed a slight increase. PM2.5 comes from a number of sources including direct emissions combustion and other sources and formation in the atmosphere from complex chemical reactions. Sources of particular concern of late include emissions from diesel engines and wildfire smoke. Average seasonal levels across the region are influenced by weather, especially temperature, wind and rain. The differences in concentration we observe at the hyperlocal level likely result from local emission sources and weather patterns that can vary at the neighborhood level.

PM WO Summer Fall 2019-1Map from summer to fall 2019 to see changes in block-by-block PM2.5 (Source: Aclima)

PM2.5 is one of the primary pollutants public health officials track closely because it is linked to asthma, lung cancer, and deaths from cardiopulmonary diseases including COVID-19. You can reduce your exposure to PM2.5 by staying indoors, particularly in buildings with good ventilation and filtration systems. If outside, reduce overall activity levels. You can check current and past PM2.5 levels nearby in the real-time section of West Oakland Insights.

Looking at hyperlocal ozone levels in West Oakland, there was a noticeable decrease in the fall averages, compared to summer 2019.

Ozone WO Summer Fall 2019-1
Map from summer to fall 2019 to see changes in block-by-block ozone (Source: Aclima)

This decrease in ozone from summer to fall was likely largely driven by cooler weather and fewer daylight hours, both of which decrease the photochemical reactions that drive ozone creation from other pollutants emitted into the atmosphere.

Conversely, hyperlocal carbon monoxide (CO) levels increased on many blocks in West Oakland from summer to fall. This was likely also due to seasonality, as cooler surface temperatures produce atmospheric conditions that result in higher street-level carbon monoxide concentrations even when emissions stay constant. Carbon monoxide results from fuel combustion and most CO in urban areas comes from vehicles.

WO CO Summer Fall 2019
Map from summer to fall 2019 to see changes in block-by-block carbon monoxide
(Source: Aclima)

If you find a pattern or area of interest in these zoomed out maps, you can zoom in by looking up the hyperlocal street-level and real-time data at

Ongoing Mapping of Hyperlocal Air Pollutant and Greenhouse Gas Levels

In order to support local action to reduce emissions and protect people’s health, we have spent years developing and testing a new way to measure what we call hyperlocal air pollution. These hyperlocal hotspots can be a symptom of nearby emissions, geography like valleys, hills, and mountains, or structures like buildings or walls trapping the pollution.

Our mobile sensor network measures fine particulate matter, ozone, nitric oxide, nitrogen dioxide, carbon monoxide, and carbon dioxide on every block in the Bay Area, measuring continuously in all nine counties night and day, weekdays and weekends. We are also currently measuring hyperlocal air pollution in southern California and Mexico with our fleet of low-emission cars serving as a roving sensor network, driven by people from the communities where we map.

We have also published interactive reports of hyperlocal pollutant levels in environmental justice areas in San Diego County as well as Richmond-San Pablo. We are continuing to map hyperlocal air quality on every block in the Bay Area, including throughout West Oakland, measuring in all nine counties 24/7, as well as in portside and border communities in San Diego.


By Melissa Lunden, Chief Scientist, Aclima