Cincinnati, OH: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, HETA 99-0090-2744, 1999 Jul; :1-18
On February 1, 1999, the National Institute for Occupational Safety and Health (NIOSH) received a management request for a health hazard evaluation (HHE) at the Gwinnett Medical Center (GMC) in Lawrenceville, Georgia. The request asked NIOSH to determine if workplace exposures are related to health problems reportedly experienced by some GMC employees working in the In Patient Surgery (IPS) and Day Surgery (DS) departments at this hospital. Health problems described in the request included dermatitis, burning and itching eyes, respiratory irritation, headache, and cough. Potential exposures included construction dust and debris, volatile contaminants from new carpet and paint, disinfectants, common cleaning chemicals, and waste anesthetic gases. On March 1, 1999, NIOSH investigators conducted an initial site visit at GMC. The purpose of this site visit was to review the current status of the health complaints with GMC personnel, inspect the IPS and DS departments and observe work practices, and assess the ventilation system supporting these two areas. A follow-up site visit was conducted on April 20-21, 1999. During this follow up site visit, eight area air samples for natural rubber latex (NRL) allergen were collected in the IPS and DS departments. Bulk and surface samples for NRL allergen analysis were obtained from ceiling plenums (ventilation return air pathways) in both departments. Because of concerns regarding latex allergy, GMC had previously implemented a powder-free latex glove policy and cleaned both the DS and IPS departments. In response to cases of clinically confirmed latex allergy in the DS department, the ventilation duct work was also cleaned. No workers in the IPS department were found to be latex-allergic and the ventilation duct work in this area was not cleaned. NRL monitoring was conducted to compare the two areas. At the time of the NIOSH site visits, the health concerns in the DS department were associated with poor indoor environmental quality (IEQ), and monitoring for standard IEQ parameters (temperature, relative humidity [%RH], and carbon dioxide [CO2]) was conducted in this area. No NRL allergen was detected on any of the air samples collected from the IPS or DS departments. However, NRL allergen was not detected on two quality control sample filters spiked with known concentrations of NRL. Therefore, a meaningful comparison of airborne NRL allergen between the DS and IPS cannot be made from these results. Regulatory standards for acceptable levels of NRL allergen in air have not been established. The bulk and surface dust samples indicated the presence, at various concentrations, of NRL allergen in the return air (RA) plenums from the IPS and DS departments. NRL allergen in bulk samples from the RA plenum in IPS ranged from 21,070 nanograms per gram sample (ng/gm) to 52,800 ng/gm. The two samples from the RA plenum in DS contained 21,067 ng/gm and 39,301 ng/gm of NRL allergen. Regulatory criteria for NRL allergen in surface or dust samples has not been established, although guidelines have been suggested (Mayo Clinic) for bulk dustsamples. The suggested recommendations for bulk dust are: Low, < 10,000 ng/gm; Low-Moderate, 10,000-100,000 ng/gm; High, >100,000 ng/gm. Although only limited samples were collected, there did not appear to be any appreciable difference in NRL concentrations in dust between the DS and IPS departments. The temperature, RH, and CO2 monitoring found all measured parameters to be within acceptable ranges. Inspection of the air handling units (AHUs) providing ventilation to the IPS and DS departments found the units to be clean and well maintained. The units are equipped with efficient filtration that should effectively prevent most dust particles from entering the supply side of the air handlers. As such, dispersion of latex containing particles from supply ducts into occupied areas is unlikely. However, because a reservoir of NRL was identified in the plenum spaces, episodic dispersion of latex-containing particles is a possibility, and actions should be implemented (e.g., proper work practices, particularly during maintenance activities) to control the potential release of NRL-containing dust into occupied areas. Humidification of supply air to the operating rooms is accomplished by direct injection of boiler steam, and there is the potential for introducing boiler water treatment chemicals into the system, and subsequently into the work environment.