The American workplace is physically and emotionally taxing, with workers frequently facing unstable work schedules, unpleasant and potentially hazardous working conditions and an often hostile social environment, according to a new study that probes working conditions in the United States.

The findings stem from research conducted by investigators at the nonprofit, nonpartisan RAND Corporation, Harvard Medical School and UCLA, and are from the American Working Conditions Survey, one of the most in–depth surveys ever done to examine conditions in the American workplace.

More than one in four American workers say they have too little time to do their job, with the complaint being most common among white–collar workers, the survey found. In addition, workers say the intensity of work frequently spills over into their personal lives, with about one–half of people reporting that they perform some work in their free time in order to meet workplace demands.

Despite these challenges, American workers appear to have a certain degree of autonomy on the job, most feel confident about their skill set and many do report that they receive social support while on the job.

“I was surprised how taxing the workplace appears to be, both for less–educated and for more–educated workers,” said lead author Nicole Maestas, associate professor of health care policy at HMS and an adjunct economist at RAND. “Work is taxing at the office and it’s taxing when it spills out of the workplace into people’s family lives.”

Researchers say that while eight in 10 American workers report having steady and predictable work throughout the year, just 54 percent report working the same number of hours on a day–to–day basis. One in three workers say they have no control over their schedule. Despite much public attention focused on the growth of telecommuting, 78 percent of workers report they must be present at their workplace during regular business hours.

Nearly three–fourths of American workers report either intense or repetitive physical exertion on the job at least a quarter of the time. While workers without a college education report greater physical demands, many college–educated and older workers are affected as well.

Strikingly, more than half of Americans report exposure to unpleasant and potentially hazardous working conditions. Nearly one in five workers – a “disturbingly high” fraction, the researchers report – say they face a hostile or threatening social environment at work. Younger and prime–aged women are the workers most likely to experience unwanted sexual attention, while younger men are more likely to experience verbal abuse.

The findings are from a survey of 3,066 adults who participate in the RAND American Life Panel, a nationally representative, computer–based sample of people from across the United States. The workplace survey was fielded in 2015 to collect detailed information across a broad range of working conditions in the American workplace as well as details about workers and job characteristics.