The NIOSH industrial hygienists, who in August conducted a health hazard evaluation of the Main Interior Building (MIB) of the Interior Department's National Business Center, also found “numerous unplanned air pathways where air pollutants generated in the renovation area can migrate to adjacent occupied areas of the building”; workers dry-sweeping construction debris rather than using wet methods or vacuuming to suppress dust; and no evidence that the contractor in charge of renovation has implemented an effective indoor environmental quality (IEQ) plan for the renovation project.
“Unless appropriate control measures are implemented (and evaluated for effectiveness after implementation), construction contaminants such as dusts, fumes and chemical odors are likely to continue to affect the occupied areas of the MIB,” NIOSH Senior Industrial Hygienist Eric Esswein wrote in a May 24 report summarizing the NIOSH findings. “ ... Occupant complaints of odors and irritant health symptoms are likely associated with exposures to construction-generated dusts and vapors due to a lack of appropriate and effective IEQ controls for renovation and construction in an occupied building.”
The Department of the Interior 5 years ago began a project to modernize all six wings of the MIB at its Washington, D.C., headquarters, which was built in the late 1930s. Although workers are removed from each wing under renovation, adjacent wings of the MIB have remained occupied during the renovation project.
Since the project began, Esswein noted, some employees have complained of “unpleasant odors and unusual dustiness, eye and upper respiratory irritation and asthma and allergy aggravation.” Prior to this latest evaluation, NIOSH had conducted two health hazard evaluations of the MIB modernization project – one prompted by a confidential employee request – to look into IEQ concerns.
Positive Pressurization NIOSH's “Most Significant Finding”
The NIOSH report offers 10 recommendations to resolve the IEQ problems in the MIB. At the top of NIOSH's list is keeping demolition and construction areas under negative pressure “for the duration of the construction and renovation project and, depending on finishes and furnishings installed, for some time after renovation has ended.”
“Maintaining a construction area under negative pressure is a standard and recommended practice when construction and renovation activities take place in occupied buildings,” Esswein wrote. “Negative pressure is recommended to ensure (to the greatest degree possible) that air contaminants such as vapors and dusts that are generated inside the construction zone are not transported into the adjacent office work areas.”
Esswein reported that NIOSH's “most significant finding was that the modernization area was intentionally operating under positive pressure with respect to the adjacent occupied office areas.” He noted that high-volume air handling units were used to supply conditioned air to the renovation area – a practice that, to his understanding, was not put in place to make workers more comfortable but rather to “prevent temperature fluctuations that might affect the structure of the building.”
For the MIB modernization project, NIOSH recommends maintaining negative pressurization of at least 0.01 to 0.02 inches of water gauge in the renovation areas.
“Because 4,000 cfm of conditioned corridor air is being supplied to each wing of the modernization area, at least 4,400 cfm exhaust air (roughly 10 percent more air than is currently being supplied) needs to be exhausted for the construction areas to be maintained under negative pressure.”
In other recommendations for the MIB modernization project, NIOSH calls on the Department of Interior, its contractor and others involved in the project to:
- Implement an effective building IEQ plan that is consistent with the Sheet Metal and Air Conditioning Contractors National Association (SMACNA) “IAQ Guidelines for Occupied Buildings Under Construction.”
- Designate individuals knowledgeable in the practice of IEQ to ensure that the SMACNA guidelines are implemented effectively.
- Improve communication of IEQ issues.
- Make sure that barricade walls installed in “communicated doorways” between the renovation area and the occupied area extend around the complete perimeter of the opening – with no gaps at the floor – and are inspected daily.
- Use high-efficiency particulate air (HEPA)-filtered vacuum cleaners to vacuum floor or surface dusts generated during demolition and construction. “In the rare occasions” when sweeping is required, a light water misting or dust coagulants should be used to suppress dust.
- “Hallway return air grilles for the HVAC systems serving the construction area should be protected from dusts generated during the work process using two layers of polyethylene sheeting, each taped and sealed separately around the perimeter of the duct opening.”
Of these recommendations, Esswein made it a point to mention that maintaining negative pressure in construction areas is “a fundamental and necessary aspect of proper IEQ when joint office occupancy and renovation activities are underway.”
“A Very Sick Headquarters Building”
At a May 22 all-employee meeting that focused on safety and health issues, Secretary of the Interior Dirk Kempthorne said that modernizing the MIB “poses special challenges.”
“This historic building is more than 70 years old and is undergoing a major, multi-year modernization to refurbish the structure, remove or safely seal the asbestos and bring the building up to code,” Kempthorne said.
Kempthorne added that those who work in the MIB “see each day the precautions that we are taking.”
“Work areas are sealed off. Negative air pressure in the work area ensures asbestos and other potentially dangerous substances do not leak around the edges. Monitors on each floor – devices that look a bit like miniature microphones – ensure that if there is any accidental release we will know about it immediately,” Kempthorne said.
Earlier in his remarks, Kempthorne said: “I want to emphasize that there is nothing more important to me personally and to the department’s mission than ensuring that your workplace is healthy and safe.”
Jeff Ruch, executive director of Public Employees for Environmental Responsibility – an advocacy group that has been critical of the safety and health conditions at the Interior Department's headquarters – blasted Kempthorne's comments as hypocritical.
“Secretary Kempthorne should either retract his recent statement on employee health or clean house of managers at his National Business Center who are badly misleading him as to the actual conditions inside his own headquarters,” Ruch said. “After 3 years of denial, Interior should finally admit that it has a very sick headquarters building and take appropriate steps to protect its workers who have been exposed too long to noxious fumes.”
Ruch noted that the Interior Office of Inspector General currently is “surveying and interviewing thousands of employees as part of an investigation into persistent health and safety problems plaguing the department.”