According to Bloomberg the U.S. Labor Department's "OSHA" regulatory agency has "cited Amazon for exposing workers to ergonomic risks at several facilities." But how widespread is the problem?

29% of America's warehouse workers are working for Amazon, a team of researchers estimates. And "More than two-thirds of Amazon warehouse workers surveyed by researchers reported that they took unpaid time off to recover from pain or exhaustion sustained on the job." The new national study, published Wednesday by the University of Illinois Chicago's Center for Urban Economic Development, found that 69% of workers surveyed stayed home without pay to recover, including 34% who did so three or more times. The data suggests "injury and pain at Amazon are far more widespread" than previously known, said Beth Gutelius, research director at the center and a leading expert on logistics and warehouse work.

The report is based on a 98-question online survey that gathered responses from 1,484 warehouse workers in 451 facilities across 42 states, the researchers said. It was conducted between April and August and measured the percentage of workers who took time off during the previous month. Amazon employs hundreds of thousands of warehouse workers in the U.S.

Amazon spokesperson Maureen Lynch Vogel said the report was "not a 'study' — it's a survey done on social media, by groups with an ulterior motive." She recommended that people read the safety data Amazon submits each year to the Occupational Safety and Health Administration, "which shows that rates in our buildings have improved significantly, and we're slightly above the average in some areas and slightly below the average in others."

41% of the workers surveyed reported being injured while working at an Amazon warehouse, according to the article. And "the share rises to 51% for people who have worked at the company for more than three years."