"Those worries are perfectly legitimate," said Tee L. Guidotti, an occupational health expert at George Washington University's School of Public Health. The growing industry of recycling used electronics, he said is known to be potentially hazardous.
While he could not comment on individual cases, Guidotti said that the inmates' and workers' concerns were similar to those affecting local communities in developing countries like China, where much of the world's used electronics end up. There, informal methods of breaking down computers by hand have resulted in severe health and environmental problems. Done improperly, recycling can release heavy metal dust, and certain methods of applying heat to break down electronics can amplify the effect of toxins, said Guidotti.
A spokesperson for the Bureau of Prisons, Traci Billingsley, said that the agency was committed to meeting all federal health, safety and environmental guidelines.
"Safeguards have been in place for several years at all recycling factories to ensure worker protection," said Billingsley.
"These safeguards include baseline testing and medical monitoring of all staff and inmates assigned to the glass breaking operations," said Billingsley.
In interviews with ABCNews.com, many UNICOR workers agreed that conditions improved after Leroy Smith, a former safety manager at Atwater prison in Merced, California, went public in 2004 with a claim that administrators had ignored his repeated warnings. The operations to break open computer monitors now happen in ventilated glass-breaking booths, and prisoners usually wear masks, protective suits, and gloves.
But the recent Inspector General's investigation into recycling facilities at Elkton Federal Correctional Institution in Ohio showed that serious problems remain. Levels of airborne lead dust at the recycling facility at times reached 50 times higher than the federally accepted level for workplaces. During a periodic filter-change operation, the level of cadmium was 450 times higher.
Lead can cause severe damage to nervous and reproductive systems, including miscarriages, said John McKernan, an industrial hygienist at the Center for Disease Control. Cadmium can cause lung damage and bone disease, and has been linked to cancer, he said. And other elements may also be present in used computers, including mercury and arsenic, which can cause skin lesions like those reported by many UNICOR workers.
The factories at Elkton were shuttered on June 27 for a thorough clean-up, said Billingsley, adding that this move went beyond inspectors' recommendations for gradual remediation. It is unclear when or whether the facilities will re-open, she said.
Similar contamination may affect other facilities that have yet to be fully inspected, according to the November 27 letter by the office's investigative counsel S. Randall Humm to an officer at the National Institute for Occupational Safety and Health.
The risks are not limited to workers and inmates. UNICOR staff "may have inadvertently exposed their families to heavy metals by wearing their dust-laden work clothes home," wrote Humm.
That, said Guidotti, should never have happened.
"They wore their work clothes home? Yikes. That has been known for years to be a set-up for exposing children," he said.
Kristin Jones is a Fellow at the Toni Stabile Center for Investigative Journalism.