After several Hanford workers complained of various physical ailments, two more were evaluated Wednesday.

The Department of Energy said two more workers in the tank farm areas complained of similar symptoms sustained by several other workers Tuesday.

These symptoms included dizziness, coughing, burning eyes, headaches, skin irritation, nose bleeds, and a metallic taste in their mouth.  The DOE did not specifically state which of the symptoms the workers experienced.

These are not new developments, since 1987, a number of Hanford workers have had similar symptoms.  Chemicals vapors are a fairly common hazard at the tank farms, many of the chemicals are a by-product of waste removal.

Ammonia is a common vapor found in the space of the tanks above the actual waste.   Ventilation systems draw the vapors out of the tanks, and HEPA filters prevent any radioactive elements from escaping, but don't stop all of the chemical vapors.   A recent study found not only ammonia in the tanks, but mercury and benzine among hundreds of chemicals.

Several of the incidents Tuesday and Wednesday occurred at tanks that were several miles apart.    Due to previous incidents, in 2003 specific limits were set for what was considered non-lethal exposure to chemicals, vapors and elements related to waste retrieval.

Vapors were detected at several single and even double-shell tanks where the ventilation systems with tall air stacks were not installed.

The workers were taken to either Kadlec Regional Medical Center or were evaluated by HPMC Occupational Medical Services at Hanford.   All but two of the workers who were evaluated have been cleared to return to work.  The two from Wednesday have not yet been cleared because HPMC did not have a chance yet to do their evaluations.

The investigation will continue. According to several Hanford watchdog groups, some workers in the past have gone on long-term disability because of past exposure to vapors.