The Federal Bureau of Prisons failed to address concerns that inmates and staff members at several prisons were exposed to toxic chemicals in recycling programs where inmates use hammers to smash discarded computers, according to the agency that handles whistle-blower complaints.

In a letter to President Bush and Congress on this week, the agency, the Office of Special Counsel, called for an independent investigation into the complaints, which were brought to the federal government by a whistle-blower from a California prison in 2004.

The whistle-blower, Leroy A. Smith Jr., the former safety manager at Atwater Federal Prison outside Merced, Calif., said factory workers in the recycling facility there and at four other federal prisons in the country were exposed to hazardous materials including lead, cadmium, barium and beryllium when the inmates took hammers to cathode ray tubes from computers.

According to federal health agencies, overexposure to the chemicals can cause cancer, kidney disease, damage to the reproductive and central nervous systems, and death.