WASHINGTON — Health care jobs are among the fastest-growing sectors in the historically low-unemployment economy President Donald Trump loves to tout. It’s immigrants who fill a lot of them — something the president might consider as he seeks new limits on immigration.

Immigrants — both citizens and noncitizens — make up a disproportionate share of workers who care for the elderly and disabled and ensure their surroundings are safe, according to a study published this week in the health policy journal Health Affairs.

The study finds more than one-fourth of direct care workers and 30.3 percent of nursing home housekeeping and maintenance workers are immigrants, underscoring their key role as the U.S. population ages. They make up 18.2 percent of the total health care workforce at more than 3 million people.

“This is a workforce responsible for everything from making sure the floors are clean and making sure our elderly and disabled don’t fall to washing linens and other things critical to wellness,” Leah Zallman, the study’s author and a physician at Cambridge Health Alliance, told me.

Health-care jobs — particularly those involving elder care — are expected to skyrocket in coming years as the baby boomers grow older. The Institute of Medicine has projected that 3.5 million more health care workers will be needed by 2030. Immigrant health care workers, who tend to be older and have more education than their nonimmigrant counterparts, are a key filler of these roles.

“Policies curtailing immigration will likely compromise the availability of care for elderly and disabled Americans,” Zallman wrote in her study.

It’s true that Trump isn’t exactly regarded as a pro-immigrant president. He’s currently seeking congressional support for cutting back on immigrant visas for relatives of U.S. citizens and replacing them with merit-based visas obtained through a points system. He has spent much of this year mired in battles with the Democrat-led House over funding for a border wall. House Democrats, however, passed a measure last night granting a pathway to citizenship for more than two million undocumented immigrants already in the country, including “dreamers,” though its chanced in the Senate are poor.

Yet despite the president’s rhetoric, the number of people becoming U.S. citizens actually reached a five-year high last year, my Washington Post colleague Abigail Hauslohner reports.

Even as the administration pledged to tighten immigration protocols (Trump’s new ICE chief says he’ll increase family deportations), the government has maintained the same rate of approving citizenship applications. U.S. Citizenship and Immigration Services reported naturalizing 756,800 people in fiscal year 2018, a 16 percent increase from 2014. Approval rates for applications declined slightly, to just below 90 percent.

“In keeping with, and even exceeding, previous years’ totals for new citizens and green cards issued by USCIS, the report’s key statistics appear to suggest efforts to limit legal immigration have not taken root,” Abigail writes.

And a steady influx of immigrants bodes well for sectors such as the health-care industry, in which worker shortages could especially be felt as the country approaches what economists call full employment. Health care had the third-highest job gains in April, with 27,000 jobs added that month, after business services and construction, my Post colleague Heather Long reported.

“The U.S. economy added 263,000 jobs in April, notching a record 103 straight months of job gains and signaling the current economic expansion shows little sign of stalling,” Heather wrote.