Abstract  In December 1981, the National Institute for Occupational Safety and Health (NIOSH) received a request to evaluate occupational exposure to chlorinated solvents at Pratt & Whitney Aircraft (P&WA). West Palm Beach, Florida. The request was prompted by reported findings of elevated blood chloroform levels and an increased prevalence of cancer in the workforce. Industrial hygiene and medical surveys were conducted 1n December 1981 and March 1982. The industrial hygiene evaluation included; 1) full shift and short term air sampling using standard charcoal sorbent tubes and a photoionization detector to evaluate current solvent exposures of 30 degreasor operators, 2) review of past industrial hygiene ·sampling data and, 3) water sampling to evaluate trihalomethane contamination levels. The medical evaluation included; 1) review of the "blood-chloroform" test, 2) pre- and post-shift urine sampling to monitor total trichloro compounds (TCC), 3) questionnaire survey and, 4) evaluation of cancer mortality using a proportional mortality ratio (PMR), a proportional cancer mortality ratio (PCMR) to correct for some inherent biases in the PMR and a case control study to determine if persons who died of cancer were more likely to have worked in areas of higher solvent exposures. Eight-hour, TWA concentrations ranged from 0.3 to 22.9 ppm for Trichloroethylene (TCE), 0.8 to 7.2 ppm for Perchloroethylene (PERC), and 0.5 to 2.0 ppm for Methylch1orofonn (MC). All were well below the current OSHA standards (TCE-100 ppm, PERC-100 ppm, MC-350 ppm) and below the 25 ppm considered by NIOSH to be achievable using engineering controls. NIOSH recommends that TCE and PERC be considered human carcinogens and therefore exposures minimized and that MC be handled with caution due to its chemical similarity to TCE and PERC. The urine test results, which measured total trichloro compounds (TTC) in post shift samples and ranged from 0.5 to 83.0 ug/gr, showed good correlation {R=0.92) with the 8-hour TWA exposure data. Peak exposures to degreasing solvents were estimated to be in the 200-300 ppm range. Occasional symptoms such as lightheadedness, headache and eye irritation reported by 20-30% of those interviewed. suggests that peak levels may occasionally exceed these values. Past environmental data indicates that 8-hour TWA exposures to degreasing solvents were generally below 25 ppm back as far as TWA data was available (1973). Analysis of water samples indicated that the new aeration units are maintaining tri-halo-methane {THM) concentrations below 0.2 ppm which is on the low end of the range (0.2-1.0 ppm) normally found in the surrounding localities. It's possible that exposures to background concentrations of chlorinated solvents, which average 2-5 ppm in the plant, are responsible for a significant portion of the reported blood-chloroform concentrations. A PMR of 156 for all cancers suggests that a 56S increased proportion of mortality due to cancer was present in this group. However. for the seven individual cancer death categories that appeared statistically significant in the PMR analyses. none remained elevated in the PCMR. This indicates that the elevated PMR was artifactual. Furthermore. there was no indication. from the case control study, that those persons who died of cancer were any more likely to have worked in an area of higher degreasing solvent concentrations than their matched controls who died of some other cause.

Abstract  Groundwater contamination by tetrachloroethene and its dechlorination products is present in two partially intermingled plumes in the surficial aquifer near a former dry-cleaning facility at Site 45, Marine Corps Recruit Depot, Parris Island, South Carolina. The northern plume originates from the vicinity of former above-ground storage tanks. Free-phase tetrachloroethene from activities in this area entered the groundwater and the storm sewer. The southern plume originates at a nearby new dry-cleaning facility, but probably was the result of contamination released to the aquifer from a leaking sanitary sewer line from the former dry-cleaning facility. Discharge of dissolved groundwater contamination is primarily to leaking storm sewers below the water table. Extensive biodegradation of the contamination takes place in the surficial aquifer; however, the biodegradation is insufficient to reduce trichloroethene to less than milligram-per-liter concentrations prior to discharging into the storm sewers. The groundwater volatile organic compounds entering the storm sewers are substantially diluted by tidal flushing upon entry and are subject to volatilization as they are transported through the storm sewer to a discharge point in a tributary to Ballast Creek. TCE concentrations of about 2-6 micrograms per liter were present in storm-sewer water near the discharge point (sampled at manhole STS26). On three out of four sampling events at manhole STS14, the storm-sewer water contained no vinyl chloride. During a time of relatively high groundwater levels, however, 20 micrograms per liter of vinyl chloride was present in STS14 storm-sewer water. Because groundwater leaks into that storm sewer and because the storm sewer upgradient from manhole STS14 is adjacent to part of the aquifer where 2,290 micrograms per liter of vinyl chloride have been detected, there is a potential for substantially increased concentrations of vinyl chloride to discharge at the storm-sewer outfall under conditions of high groundwater levels and low tidal flushing. In addition, the observation that free-phase tetrachloroethene may have entered the storm-sewer system during the 1994 discharge means that dense nonaqueous phase liquid tetrachloroethene could have leaked from various parts of the storm sewer or discharged to surface water at the storm-sewer outfall.