RICHLAND, Wash. -

Many workers at the Hanford Nuclear Reservation do not trust the way the U.S. Department of Energy and its contractor are managing the issue of chemical vapors that are sickening some employees.

That was a key finding of a report issued this week by the National Institute for Occupational Safety and Health.

The report found that thousands of air samples taken in and near nuclear waste storage tanks have shown few, if any, exposures exceeding occupational limits.

The Tri-City Herald reported that the vapors issue has bedeviled the sprawling former nuclear weapons production site for years. Six more workers were given medical evaluations Wednesday for possible exposure to chemical vapors, bringing the total since spring to more than 60. Nearly all were cleared to return to work after medical evaluations.