The number of local residents who speak a foreign language at home or say they don't have a command of English is on the rise, according to U.S. Census Bureau data illustrating the wide-ranging effects of immigration.

Nationwide, nearly one in five people living in the United States speaks a language at home other than English, according to a report from the American Community Survey taken last year by the U.S. Census.

In Southern California, the number is higher, and the majority of non-English speakers reported speaking Spanish.

In Escondido, the number of people who didn't primarily speak English at home in 2006 stood at about 45 percent of the city's population of about 127,000. That is up about 6 percentage points from the turn of this century.

In Oceanside, the number of those who speak a foreign language at home hovers around 35 percent of the city's current population of about 149,000. That is up about 3 percentage points from 2000 - although that percentage appears to fall within the statistical margin of error, the data state.

In the rapidly growing Riverside County bedroom community of Murrieta, the number of people who speak a different language at home has jumped in the last five years from about 15 percent of the city's residents to more than 27 percent.

The use of languages other than English has been a touchy issue for many groups in San Diego and Riverside counties, where conservative politicians have campaigned for stricter immigration laws and reduced dependence on other languages, especially Spanish. But others have accepted or embraced the use of many languages in the border region, where ballots are printed in at least four languages and people are almost as likely to hear Spanish, Vietnamese or Tagalog spoken on the streets as they are to hear English.

The number of immigrants nationwide reached an all-time high of 37.5 million in 2006, affecting incomes and education levels in many cities across the country.

California led the nation in immigrants, at 27 percent of the state's population, and in people who spoke a foreign language at home, at 43 percent. The U.S.-born children of immigrants often speak their parents' native languages at home.

The Census Bureau on Wednesday released a host of demographic data about the nation, including statistics on immigration, housing, education and employment.

The data came from an annual survey of 3 million households. It does not distinguish between illegal immigrants and those who are in the U.S. legally.

In San Diego County, 14,732 households responded to the survey. Riverside County had 9,824 responses.

When it came to language, respondents were asked to rate themselves on their comfort level with English, with options ranging from very well, well, not well and not at all.

The survey was given in English. When necessary, census workers called and visited the homes of people who did not respond, and were sometimes able to communicate in the respondent's native language, a census spokeswoman said.

Language barriers mean added pressure for local school districts, educators said.

In Murrieta, the rise in the number of people who speak a foreign language at home is reflected in classrooms, where the number of students learning English increased by more than 300 percent from 2002 to 2006.

"That's very significant," school district spokeswoman Karen Parris said. "If you have a large number struggling with English, it affects their other studies. And those students also need more support and intervention."

Classes are primarily taught in English, with some help and further instruction available in students' native languages. And Parris said the demands do tug on the district's purse strings.

In North County, the Oceanside Unified School District has taught all classes in English for about a decade.

"Our goal is to get them using English as soon as possible," said District Superintendent Larry Perondi. "The best way to become proficient is to use it and write it and hear it."

More adults are also learning English in Oceanside. Two years ago, about 500 adults took English classes offered by the school district. This year, that number is about 800.

"We don't lack for people who want to be in English language classes," Perondi said.

Children tend to learn English and act as translators for their parents who don't speak the language, said Bonnie Bade, the chairwoman of the anthropology department at Cal State San Marcos. And when the children of non-native English language speakers grow up, their children speak English, she said.

"I really don't see it as a problem. When we look at history, the kids learn English."

Bade also noted that San Diego county has a number immigrants with different languages and cultures.

"If we want to hang onto some kind of a myth that this is some kind of a homogeneous society, that is not reality, and it hasn't been for a very, very long time," Bade said.

- The Associated Press contributed to this report. Contact staff writer Teri Figueroa at (760) 631-6624 or tfigueroa@nctimes.com.