Impact of Polluted Air on SF Unhoused Community Left Uncharted on CalEnviroScreen Map

The CalEnviroScreen map is a pollution tracking tool developed to more clearly identify California communities with high environmental burdens and better focus where state and federal funding should go. However, when LaDonna Williams looks at this map, she notices the environmental hazards that the cartographers missed.

“Some of these communities have several exposures,” Williams says. Some are simultaneously situated next to raw sewage plants, refineries and highways. But when this data is translated through the CalEnviroScreen scoring system, these communities are not always flagged as vulnerable and miss out on much-needed funding.

Williams, the program director of Richmond-based nonprofit All Positives Possible, has as much experience navigating the world of grant funding as physical geography. Her organization serves low-income communities of color across the Bay Area facing the health, economic and social impacts of pollution burdens in their communities.

One such community is at Pier 94, where the SF Port Commission created 120 COVID shelter beds for the City’s unhoused residents last spring. However, a recent NBC Bay Area investigation deemed these shelters to be the “worst place to live” due to the particulates in the air from gravel manufacturer Hanson Aggregates next door. The particulate matter is fine enough to penetrate through the shelters. The situation is so hazardous that residents are asked to wear masks even when indoors. 

A source who wishes to remain anonymous describes what they witnessed when visiting a family member at the shelters. Folks living at the shelter complained about more frequent breakouts and skin problems. Some even noticed that their vehicles were being affected by the presence of the dust particles. 

“They complain at me, but they’re too scared to complain to [the United Council of Human Services] because they will get put out,” says the source. This is a valid fear; when this source first started speaking out about the conditions at Pier 94, a family member who was living at the shelters at the time was pushed out.

Pier 94 sits at the top of Bayview, a largely Black San Francisco neighborhood with a population of about 38,000. On CalEnviroScreen, Pier 94 is noted to be “high pollution, low population” but it’s not even given a score; instead, it sits unmarked. 


CalEnviroScreen (CES) has been lauded as a tool for environmental justice by the media and the government. Its mission — to provide a cumulative look at how pollution affects California communities — is quite revolutionary. However, it is not a perfect science.

In order to determine how vulnerable a community is, CES uses data from government agencies to identify the presence of environmental risk factors in an area. These risk factors fall into two categories: exposures and environmental effects. 

Exposures include pollutants like PM2.5 and exhaust from diesel-powered vehicles, while environmental effects describe a community’s proximity to hazardous sites like waste facilities and groundwater threats. To calculate an area’s overall score, CES averages the scores of each of those categories and then multiplies them by the averaged score of the community’s population characteristics. However, environmental effects are only weighted at half, whereas exposures are weighted fully.

CalEPA — the agency in charge of creating this tool — said it calculated environmental effects at one-half because the agency doesn’t consider them to be immediate threats; these sites may be present and somewhat hazardous, but they’re not necessarily actively emitting hazardous material.

Emily Nelson is an alumnus from California State Polytechnic University with a master’s in regenerative studies who disagrees. “Suggesting it is less important than other indicators is irresponsible when there is overwhelming evidence that it can cause disease and death,” she writes in her 2018 thesis, ‘Analyzing Potential Biases of CalEnviroScreen 3.0.’

In this essay, Nelson references studies that look at the concentration of lead and organochlorine in the blood of residents living close to hazardous sites. The conclusions are all the same — the closer a community is to a hazardous site, the higher the levels of hazardous chemicals there are in their blood. 

These hazardous chemicals can manifest as a myriad of illnesses in the communities they are present in. Often, like in the case of DDT, some of the effects are even passed on through generations.

Nelson adds that certain communities – like Pier 94 – are not represented because there’s, “a large amount of missing data from several census tracts.” Since CES multiplies a community’s pollution burden by their population data, communities with fewer residents – or missing census data – automatically score lower.

Both Nelson and Williams wonder: would it be more equitable if, for now, this data was left out? 

A spokesperson from CalEPA’s Office of Environmental Health Hazard Assessment (OEHHA) noted that their agency was aware of these criticisms and that was the reason behind the constant updates of CES. They also mentioned that communities like Pier 94 — that are currently unmarked on the map — are internally designated by the state as “disadvantaged” and receive dedicated funding through Senate Bill 535, a law that directs money from polluters’ fines directly to impacted communities.

However, there are many other funding opportunities that are not available to them; ones that they could especially benefit from. Last year, the Bay Area Air Quality Management District was accepting applications for the James Cary Smith Community Grant Program, which offered $750,000 to organizations serving disadvantaged communities. Like many similar grants, CES is used as a metric to determine where to allocate funds. 

Though the residents of Pier 94 could greatly benefit from this funding, they – like others – will instead be left out.