Health hazard evaluation report, HETA-2001-0210-2859, DynCorp Technical Services, Columbus, Mississippi.
On March 14,2001, the National Institute for Occupational Safety and Health (NIOSH) received a request for assistance from the Occupational Safety and Health Administration (OSHA) regarding DynCorp Technical Services in Columbus, Mississippi. OSHA requested that NIOSH conduct a health hazard evaluation (HHE) regarding a potential cancer cluster and worker health complaints at a private contractor facility servicing military jet aircraft at Columbus Air Force Base. Specifically, employees were concerned about exposure to emissions from two industrial ovens used to heat treat engine components in Building 218. On April 4, 2001, a NIOSH investigator conducted a site visit to the DynCorp Technical Services Building 218. The objectives of this site visit were to review the health complaints at the facility, obtain additional information regarding the occurrence of cancer among employees who worked in this building, and characterize the emissions from the two industrial ovens. During the site visit, a walkthrough of Building 218 was conducted and material safety data sheets (MSDSs) for chemicals used in this building were reviewed. Subsequent activities included collecting air samples to characterize emissions from the ovens, holding informal discussions with employees regarding their health concerns, and reviewing work practices. The environmental monitoring was conducted using a qualitative broad spectrum technique which can identify a wide range of contaminants, as well as substance specific monitoring for carbon monoxide (CO) and oxides of nitrogen. For control purposes, samples were collected prior to operating the ovens and also from an adjacent administrative area. Information regarding the cases of cancer was obtained from the shop supervisor, individuals with cancer, and persons knowledgeable about those who had passed away with cancer. The shop was clean, orderly, and no open chemical containers, or evidence of spills were found. Various solvents, lubricants, adhesives, and oils commonly found in engine repair facilities were present throughout the shop. Employee health concerns were primarily associated with exposure to contaminants from the bake ovens; other than occasional odors, no reports of irritation or discomfort were noted. An unrelated employee concern was noted regarding jet fuel remaining in engines and inadequate means for removing this fuel during maintenance. During oven operation, visible emissions escaped from the seals and passive exhaust ports at the top of both ovens. A wide variety of compounds typical of those expected to be present in an engine maintenance facility were detected on all air samples collected. These included a number of aliphatic hydrocarbons, toluene, and other compounds normally associated with solvents, degreasers, and oils. Although quantitative data was not obtained, comparison of air samples collected prior to oven operation with those collected while the oven was in use did not identify any substantive differences in relative concentrations. Similarly, the process and control samples collected from the Administrative office were not substantially different and the results suggest that the Administrative office is isolated from the main work shop. Instantaneous air monitoring using direct-reading colorimetric tubes did not identify any detectable CO (less than one part per million) or oxides of nitrogen. Information provided to NIOSH described several different types of cancer among DynCorp employees. These cancers do not appear to represent an unusual number of cancers. In addition, neither the distribution of other cancers, exposures expected within the engine shop, nor latency period suggest an occupational etiology. Environmental monitoring indicates that the two industrial ovens are not substantial contributors to workplace airborne contaminants in Building 218. The characteristics of the cancer cases did not suggest an occupational etiology. To address worker concerns and resolve questions regarding the ovens, a prudent course of action would be to ventilate the ovens outdoors. Recommendations for oven ventilation and removal of jet fuel from the ovens is provided in the Recommendation section of this report.