NEW CONCERNS OVER TANK VAPORS
WC Monitor
3/28/2014
Hanford officials have identified two potential sources of chemical vapor emissions after workers reported symptoms at the tank farms over four days this week and last week. At least 18 workers have reported symptoms linked to possible chemical vapors from tank waste, with the latest case on the afternoon of March 27. All workers have been cleared to return to work, including four workers sent to the hospital and released the same day and the additional workers who were sent for evaluation to the Hanford medical provider, HPMC Occupational Medical Services.
Hanford tank farms contractor Washington River Protection Solutions held a series of meetings with workers March 27 to discuss possible sources of the vapors and what is being done to protect workers. It told workers an investigation found a cut in insulation surrounding a pump pit in the A Tank Farm, which is near an area where symptoms were reported. The cut was sealed with foam and the area was re-evaluated, with instruments no longer detecting elevated levels of potential vapor-causing compounds in the area, according to WRPS.
Workers at Various Tank Farms Affected
On March 25, the combined AY and AZ Tank Farms were evacuated when seven WRPS workers smelled vapors and developed symptoms. The next day, three workers for other contractors or subcontractors said they also had experienced symptoms on March 25 while working near the AY and AZ Tank Farms. In addition two WRPS workers reported symptoms there last week and the worker who had symptoms March 27 was also in that area.
In the S Tank Farm, where two workers were sent to the hospital March 25, the investigation has focused on liquid in old, unused equipment that had been staged for disposal. The workers had been cutting plastic wrapped over a block covering the equipment when they experienced symptoms. The area around the old equipment has been cordoned off as a vapor control zone and the liquid is being sampled and analyzed to determine if it may be a potential source of emissions, according to WRPS. An investigation at the T Tank Farm, where workers reported smelling vapors March 26, has found no detectable measurements of vapor-causing compounds, according to WRPS. But investigations to identify other potential sources of vapors are continuing.
Vapors Have Long Posed Concern
The symptoms of all of the workers exposed recently have not been made public. But tank farm workers exposed to vapors at Hanford have generally reported such symptoms as sore throats, headaches, coughing, burning eyes, nose bleeds, a metallic taste, dizziness or an accelerated heart rate. Workers fear that exposure could cause long-term health problems. Hanford Challenge believes that past exposures to workers have led to cases of toxic encephalopathy, neurological damage and long-term chemical sensitivity.
Workers have reported smelling tank vapors for at least the last two decades at Hanford. Changes have been made through the years to better protect workers, including alarms that sound when chemicals are detected, more industrial hygiene professionals at the tank farms and increased monitoring for chemicals with a combination of techniques. Workers generally smell ammonia, one of the chemicals in the headspace of the tanks. But a study by the previous tank farm contractor, CH2M Hill Hanford Group, found about 1,500 chemicals in the headspace of the tanks, including mercury and benzene. The issue came to a head in 2003, resulting in multiple studies by the state of Washington, federal organizations, independent consultants and Hanford watchdog groups. Exposure limits that consultants considered to be safe were set and changes to venting systems were made at the tank farms.
WRPS Stresses Safety
WRPS has kept worker exposure to chemical vapors far below national occupational standards, generally 10 percent of those standards, said Jerry Holloway, WRPS spokesman. In meetings March 27 it encouraged workers to wear respirators if they believe it is necessary. WRPS has an Industrial Hygiene Technical Panel, with management and employee members, which meets regularly to address chemical vapor issues and concerns, including identifying potential hazards and developing controls. It also will be addressing the recent chemical vapor issues, Holloway said.
The risk of chemical vapors at the tank farm cannot be completely eliminated, but WRPS is continuing to look for ways to reduce risk to workers, it said in a statement. It takes a conservative approach to dealing with risks, including minimizing worker exposure and providing an appropriate medical response, if needed, it said. However, Hanford Challenge said not enough is being done to protect workers. Late this week it called for WRPS and DOE to support workers who have experienced symptoms, to step up monitoring of chemical vapors and to take more protective measures.
