CalEnviroScreen 2.0: Percent of households in which no one age 14 and over speaks Engligh "very well" or speaks English only

American Community Survey U.S. Census Bureau 

The American Community Survey (ACS) is an ongoing survey of the U.S. population conducted by the U.S. Census Bureau and has replaced the long form of the decennial census. Unlike the decennial census, which attempts to survey the entire population and collects a limited amount of information, the ACS releases results annually based on a sub-sample of the population and includes more detailed information on socioeconomic factors such as poverty. Multiple years of data are pooled together to provide more reliable estimates for geographic areas with small population sizes. The most recent results available at the census ZIP code are the 5-year estimates for 2008-2012. The data are made available using the American FactFinder website.

From 1990 to 2000 the number of households in the U.S. defined as
“linguistically isolated” rose by almost 50% (Shin and Bruno, 2003).
While the percentage of immigrant households in California that are
linguistically isolated is comparable to the national percentage, according to the 2009 American Community Survey (Hill, 2011),  California has a higher proportion of immigrants than any other state
and the immigrant population has increased by 400% since 1970 (Johnson, 2011). The inability to speak English well can affect an individual’s communication with service providers and his or her ability to perform daily activities. People with limited English are less likely to
have regular medical care and are more likely to report difficulty getting medical information or advice than English speakers. Communication is essential for many steps in the process of obtaining health care, and limited English speakers may delay care because they lack important information about symptoms and available services (Shi et al.2009). Non-English speakers are also less likely to receive mental health services when needed, and because in California non-English
speakers are concentrated in minority ethnic communities, limited English proficiency may contribute to further ethnic and racial disparities in health status and disability (Sentell et al.2007). Linguistic isolation is also an indicator of a community’s ability to participate in decision-making processes and the ability to navigate the political system.

Lack of proficiency in English often results in racial discrimination, and
both language difficulties and discrimination are associated with stress, low socioeconomic status and reduced quality of life (Gee and Ponce, 2010). Linguistic isolation hampers the ability of the public health sector to reduce racial and ethnic disparities because non-English-speaking individuals participate in public health surveillance studies at very low rates, even when there is translation available (Link et al., 2006). In the event of an emergency, such as an accidental chemical release or a spill, households that are linguistically isolated may not receive timely information on evacuation or shelter-in-place orders, and may therefore experience health risks that those who speak English can more easily avoid. Additionally, linguistic isolation was independently related to both proximity to a Toxic Release Inventory (TRI) facility and cancer risks by the National-Scale Air Toxics Assessment (NATA) in an analysis of the
San Francisco Bay Area, suggesting that linguistically isolated
communities may bear a greater share of health risks from air pollution hazards (Pastor et al,. 2010).