About three-quarters of the people working in health care jobs are women, and a new national study from Massachusetts General Hospital and the University of Pennsylvania finds a large share of them earn low wages and have few benefits.

The researchers found 34 percent of female health care workers made less than $15 an hour in 2017, including nearly half of black and Latina women in the health sector. Kathryn Himmelstein, a lead author of the study, blames the income gap on gender and racial divisions in the health care workforce.

“A much larger share of men in health care work as physicians and managers, and a larger share of women work as nurses and nurse’s aides,” says Himmelstein. “And then, the occupational structure is racially stratified.”

She says white and Asian women make up a higher percentage of doctors and nurses, while more black, Latina and Native American women work as nurse’s aides, home health aides, and in nursing homes and assisted living facilities.

In total, the study estimates 1.7 million women in health care and their children live in poverty. Himmelstein recommends raising the minimum wage to address this income gap.

While the minimum-wage debate has often centered around jobs in fields like fast-food and child care, Himmelstein says increasing it to $15 an hour would dramatically help those who work in many facets of health care, as well.

“It would reduce poverty among women health care workers by up to 50 percent. And the costs associated with that are relatively modest,” says Himmelstein. “So, less than 1.5 percent of total health care spending.”

The research team analyzed 2017 Census Bureau data, and more than 10,000 health care workers responded to an economic supplement. The results are in the January issue of the American Journal of Public Health.

Laura Rosbrow-Telem is a reporter for the Commonwealth News Service