The Project Area: Past and Present
The Excelsior District consists of a vibrant working class community and is home to many young people, immigrants, and families of color. Despite these strengths, the neighborhood is also is disproportionately exposed to concentrated traffic pollution. It is cradled by the 280 freeway, and large busy thoroughfares including Alemany Boulevard, Mission Street, Geneva Avenue, and San Jose Avenue. These corridors provide shortcut routes for many heavily polluting diesel trucks and buses in addition to the thousands of vehicles that pass through the area each day.
This heavy traffic results in levels of roadway air pollutants in excess of those associated with ambient air quality. These elevated levels of air pollutants result in exposures that are uniquely high to those residing in this “freeway channel”, and will have negative health effects consistent with the elevated exposure. These effects include increased childhood asthma and adult respiratory disease. The traffic also generates environmental noise that can cause sleep disturbances and stress known to affect school and work performance, temperament, hearing impairment, and high blood pressure. Heavy traffic volume and high traffic speeds also pose dangers to pedestrians, and can create an environment that discourages walking, playing in the neighborhood, and community interaction. These effects generate further implications for public safety.
We define the study project area as the immediate neighborhood surrounding the Still / Lyell Freeway channel. The confluence of the freeway and busy thoroughfares in a residential neighborhood is symptomatic of transportation patterns that occur throughout South East San Francisco. In fact, the Chinese Progressive Association (CPA) has been working together with the SF Department of Public Health to document similar air quality impacts in the communities in and around the 101 freeway, such as Silver Terrace, Portola, and Visitacion Valley.
Highway 280 Construction
Based on historical demography and a review of newspapers and public documents, our project incorporates a retrospective view of the health impacts of the decision to construct the Southern Freeway, Highway 280.
Built amidst the political turmoil of the “Freeway Revolt” of the early 1950s, in which other planned freeways were not constructed due to public opposition, the Excelsior segment of San Francisco’s I-280 displaced hundreds of families and dramatically altered the residential configuration of the surrounding area, shaping the noise, air pollution and traffic levels that impact the community’s health today.
As a part of our project, students from the Fall 2007 UC Berkeley Environmental Justice Class reviewed historical documents and newspapers at the San Francisco Main Library and prepared a historical perspective of the decision to built the freeway, the public response to this decision, the city’s rationale for building the freeway, and the students’ analysis regarding why community opposition was unsuccessful in preventing the Southern Freeway from being built through the Excelsior.
The freeway provides a dramatic backdrop to the traffic impacts arising from busy thoroughfares, one-way streets, and heavy traffic including many diesel trucks right in the heart of residential areas. The UC Berkeley Environmental Justice Class student historical assessment will eventually be incorporated into our larger analysis of the freeway and its health impacts on the local residents.
Community Demographics: 1960 - 2000
Given the historical context of the Excelsior community being divided by the I-280 freeway in the mid-1900s, we also wanted to consider how the demographics of the community have changed since the construction of the freeway based on U.S. Census data from 1960-2000. We hypothesize that populations living close to the freeway have been disproportionately affected by environmental hazards that are commonly associated with living near freeways, such as noise and air pollution. Changes in the demographics of these areas impacted by freeways directly relates to changes in the populations exposed to these hazards.
Our more dramatic findings confirm that the number of people at risk has grown exponentially over the last generation as more working families and people of color reside in the neighborhoods adjacent to the freeway. Today, the Excelsior and neighborhoods on the south east side of town are denser than ever before. They have experienced a dramatic increase in the number of children, with close to half of all households being families with children. Our Retrospective Analysis of the Changing Demographics of a Community after the Construction of a Freeway provides details of these findings.
Percent Increase in Children, 1960-2000
Rather shocking, the temporal trend shows that for the project site area the percentage of the population that are children has increased greatly between 1960 and 2000 - more than any of the other areas. These findings suggest that the environmental hazards of living near to freeways may in some cases disproportionately affect children.
