It’s no secret that the Bay Area has become increasingly unaffordable for many workers because of the soaring cost of housing. But a recent study gives a glimpse into just how much the region’s sky-high rents are gobbling up the paychecks of one core segment of its work force: teachers.

The Bay Area has three of the least-affordable cities in the country for teachers, San Francisco, Oakland and San Jose, based on a recent analysis of teachers’ salaries and median rental prices among 50 of the nation’s largest cities by San Francisco-based ApartmentList.com, which tracks rents across the country.

Not surprisingly, San Francisco topped the Top 10 list of cities that lack affordable housing for teachers, with 69 percent of paychecks for mid-level teachers with five years experience going to rent for a one-bedroom apartment, based on 2016-2017 salaries. Oakland placed sixth in unaffordability, with 46 percent of teachers’ income going to rent. And San Jose placed eighth, with 43 percent of their income getting swallowed up by rent.

Housing costs should consume no more than 30 percent of one’s income to be “affordable,” according to many housing experts.

By comparison, the most affordable large cities for teachers to live and work were Wichita, Kansas; Fresno; and Memphis, Tennessee, where rents made up 14 to 15 percent of teacher incomes, according to the survey.

“It’s worries me, ” said Mary Claire Delgado, Oakland Unified School District’s recruitment manager, in response to the study’s results. “The Bay Area and Oakland have so much to offer new teachers. We attract the brightest and most diverse individuals from all over the world and bring together people from all walks of life. But the issue has become: Is it sustainable for a new teacher to live and work here and continue their careers here, as they gain extended families?”

Her district has tried to at least partially address the problem by raising teacher salaries by about 8 percent over the past year, and by passing a 12-year, $120-per-year parcel tax in November to raise $12.4 million aimed partly at providing better pay for teachers. But school and city leaders are working collaboratively to try to help fix the problem, she said.

Peter Allen, San Jose Unified School District’s spokesman, said that starting teachers at his district make $55,000 a year, which is better than most districts. “But realistically, you have to be making $100,000 to just afford the rent here,” he said.

To try to alleviate that problem at least in part, San Jose Unified also passed in November a $72-per-year parcel tax for eight years that will raise about $5 million annually help pay a bit more to its teachers, he said.

“But that’s just one piece of the puzzle. It’s not the solution,” he said. “There are market factors that we don’t have any control over.”

The study also found that in the Bay Area, Pittsburg and San Pablo are the only cities where teachers can live without spending more than 30 percent of their income on rent. In San Pablo, the median one-bedroom rent is $1,150 — which eats up around 23 percent of a fifth-year teacher’s salary. But both cities are more than an hour’s commute from San Francisco, at least an hour-and-30-minute commute from San Jose and about a 45-minute commute from Oakland during morning rush hour, putting a significant strain on teachers who choose to live in more affordable cities and commute to those school districts, the study notes.

Similarly, Allen said San Jose teachers are moving to lower-cost communities such as Tracy, which is also more than hour’s commute away, to find affordable housing, or looking elsewhere for jobs.

“Teachers just starting out get offered a job here, and they are all excited,” he said. “And then they look for housing, and then reality kicks in, and they said we didn’t realize how difficult it would be. We lose a lot of teachers that way. No matter what we do, it doesn’t pencil out.”

Jennifer Thomas, president of the San Jose Teachers Association, said her district has a 15 percent teacher turnover rate annually, and much of that is due to the high cost of living in the area.

Teacher turnover also disproportionately harms the district’s highest-need students and highest-need schools, she said.

“Veteran teachers are necessary to ensure equity in educational outcomes,” she said. “But Silicon Valley is not producing enough veteran teachers, and all due to the cost of living.”

A number of bills on the state level are trying to tackle the affordable housing problem for teachers, such as Assembly Bill 45, sponsored by Assemblyman Tony Thurmond, D-Richmond, which would give out $100 million in state funding to help school districts partner with developers to build teacher housing, such as has occurred in Los Angeles and Santa Clara counties, and is being considered in San Francisco.

In addition, Assembly Bill 1157, sponsored by Assemblyman Kevin Mullin, D-San Mateo, would encourage districts to turn surplus property into school district employee housing.

But Trish Gorham, president of the Oakland Education Association, said her group has rejected any teacher housing proposals that would “carve out” housing for teachers and give them “a privileged place” to live, when other Oakland families don’t have the same opportunities.

That’s because the affordable housing problem for teachers is “a reflection of a real societal problem that can’t be solved piecemeal by giving teachers a break here or there,” she said. “It’s more widespread than that.

“And it’s good they are using teachers as the frame,” she said about the region’s affordable housing crisis. “What it shows is that teachers are really the canary in the coal mine. It illustrates the squeezing of the middle class and the disappearance of the middle class.”