WASHINGTON -- Automatic mail sorting machines used in Postal Service centers across the country pose a serious health risk, forcing workers to engage in awkward, repetitive movements that can inflict serious back and arm problems, according to a government investigation.
Work at the machines "is potentially hazardous to employees due to design flaws and the high volume capacities of these machines," says a report by the National Institute for Occupational Safety and Health.
A copy of the report, which was sent to postal authorities in Denver last Thursday, was obtained by the Los Angeles Times.
The Postal Service refused to comment on the study. "I haven't seen a copy of the report yet," said Dr. Rose Hayes, the Postal service specialist in ergonomics -- the study of equipment and its impact on the health of workers.
Workers in the Denver mail-processing center asked for the investigation by the institute, which is a branch of the federal Department of Health and Human Services. Ergonomic experts studied videotapes taken by investigators showing postal workers using the equipment at major mail-processing centers in Merrifield, Va., in August, and Denver in December.
The equipment is at the heart of the Postal Service's continuing automation program, which emphasizes equipment that can read addresses and speed the sorting and delivery of mail.
The machines are called optical character readers, bar code sorters and delivery bar code sorters. By 1995, the Postal Service will have more than 9,000 of the machines installed at major centers across the country. They are used by three shifts of workers, 24 hours a day.
Government investigators found serious problems with two of the three types of machinery -- optical character readers and delivery bar code sorters -- that could put at potential risk the health of many thousands of workers.
Workers who feed mail to the optical character readers are at risk of low back problems because the feeding table is lower than the "recommended work surface height," the report notes.
Feeding mail into the delivery bar code sorter places "the shoulders, lower forearms and hands at risk for musculoskeletal disorders," according to the report.