About half of workers at pork processing plants, like the JBS slaughterhouse in Worthington, Minn., are at high risk of developing musculoskeletal diseases. (Elizabeth Flores/The Minnesota Star Tribune)

More than 80% of poultry slaughterhouse workers and half of hog processing employees testing faster line speeds are at high risk of developing chronic conditions like arthritis and carpal tunnel syndrome, according to recent U.S. Department of Agriculture reports on line speeds and worker safety.

Current line speeds run up to 140 birds per minute for poultry and 1,106 hogs per hour for swine, but some plants — including Quality Pork Processors in Austin, Minn. — can operate at faster speeds through May 15 and were the basis for the USDA studies.

The line speeds, the rate at which animals are slaughtered and processed, have long been a point of contention for slaughterhouse employees and their unions.

Faster speeds cut costs, but unions and other worker advocates are worried they would result in more worker injuries.

The USDA’s studies found it was the piece rate — the number of animal parts a worker handled per minute — that was more associated with a higher risk of musculoskeletal diseases (MSD).

“Reducing piece rate, by increasing job-specific staffing or decreasing job-specific line speed, may reduce musculoskeletal disorder risk for workers,” the agency said.

More than 17,500 Minnesotans work in meatpacking plants, according to federal data. The state leads the nation in turkey production and is the second-largest pork producer after Iowa.

The USDA studies say 40% of poultry workers reported “moderate to severe work-related pain” over the prior year and 42% of pork processors had “moderate to severe upper extremity pain” among the 17 facilities testing faster line speeds.

The union representing workers at Hormel Foods and the JBS pork plant in Minnesota said the studies “reaffirm what we have long known — that poultry and swine slaughter poses serious risk to workers, regardless of line speed," UFCW International President Marc Perrone said in a statement.

“The UFCW is calling for a full range of safety measures including additional staffing, improved reporting of workplace injuries, expanded access to early and adequate medical treatment and job modifications that minimize ergonomic stressors,” Perrone said.

In recent years, the UFCW successfully sued to block a Trump-era rule that would have abolished line speed regulations for hog plants.

The National Pork Producers Council (NPPC), meanwhile, has a different take on the study. It praised the USDA study results and said they ”confirmed that increased line speeds are not a leading factor in worker safety.”

“Pork producers appreciate USDA’s thoughtful and thorough approach to maintaining increased packing capacity, giving us more opportunities to safely and more efficiently deliver our products to consumers,” Lori Stevermer, NPPC president and a Minnesota pork producer, said in a statement.

The pork industry group says it will ”find ways to continue expanding and making permanent these increased line speeds to help alleviate supply issues."

The average price of pork chops and bacon remained near record highs at the end of last year.

U.S. Rep. Brad Finstad, who represents southern Minnesota, said the swine study “proves that pork processors can do their jobs safely and effectively while operating at full capacity.”

“I’m proud to have led several initiatives urging the USDA to implement a more permanent solution, and I look forward to working with the Trump administration to make real progress for our pork processors,” the Republican posted on social media.

The National Chicken Council said the study justifies a line speed increase, to a minimum of 175 birds per minute, and pointed to staffing levels as a solution to injury concerns.

“While piece rate, the number of chicken parts handled per minute by each worker, was associated with increased risk, this was offset by adequately increasing the number of workers doing the job,” the group said.

The USDA said “current risk mitigation efforts are insufficient,” however.

A union representing 15,000 poultry workers, mainly in the southern states, joined the UFCW in calling for greater worker protections and adequate staffing levels.

“Poultry workers toil in cramped, cold conditions, slicing up birds thousands of times per hour as chickens rush down the line,” said Stuart Appelbaum, president of the Retail, Wholesale and Department Store Union. “It’s no surprise that poultry workers are twice as likely as the average American worker to suffer a severe wrist injury, and seven times as likely to develop Carpal Tunnel Syndrome.”