Health hazard evaluation report: HETA-2001-0109-2835, Lac Vieux Desert Resort and Casino, Watersmeet, Michigan.
On December 13, 2000, the National Institute for Occupational Safety and Health (NIOSH) received a management request for a health hazard evaluation (HHE) at the Lac Vieux Desert Resort and Casino in Watersmeet, Michigan to determine if workplace exposures during counting operations are related to reported health problems that some employees have experienced. Specifically, NIOSH was asked to evaluate exposure to metal dust and other contaminants associated with machine counting of coins and paper money at the casino. Reported symptoms included eye, nasal, and respiratory irritation, and other respiratory problems. On January 25-27, 2001, NIOSH researchers conducted a site visit at the Lac Vieux Desert Resort and Casino. The purpose of this site visit was to review the coin counting process, interview employees, and characterize the work environment to determine factors that may contribute to the reported symptoms. During the first shift (12:00 AM - 8:00 AM) on January 26 and January 27, environmental monitoring was conducted to evaluate count employees personal exposures to nickel, copper, zinc, and other metals that may be present in coin dust, and to the total dust present in both the hard (coin) and soft (paper) counting areas. Surface samples were collected to determine the extent of metal contamination in various areas, and personal noise monitoring was conducted to evaluate worker exposure to noise. The results of the air sampling showed that for the monitoring period all measured concentrations of nickel, copper, and zinc were below the NIOSH Recommended Exposure Limits (REL) for these substances. The highest measured concentration of nickel was 7 micrograms per cubic meter (µg/m3 ), detected in a sample collected from a coin count worker. The NIOSH REL for nickel is 15 µg/m3 . The highest copper concentration (24 µg/m3 ) was measured in this same sample. The NIOSH REL for copper dust is 1000 µg/m3 . All zinc samples were either below the limit of detection (LOD) or between the LOD and the limit of quantitation. The NIOSH REL for zinc oxide is 5000 µg/m3 . The surface sampling results identified some areas in the coin counting room where additional cleaning is warranted to reduce the potential for spreading metal contamination or generating airborne dust. All measured noise exposures were below the NIOSH REL of 85 decibels on the A-weighting scale (dBA) as a full-shift time-weighted average. Workers reported nasal, respiratory, and eye irritation; no skin problems were reported by any of the workers. A number of manual lifting activities involving substantial loads and awkward postures were observed, most of which involved handling the coins. Based on a limited review of the ventilation system and information provided by casino employees, it appears the heating, ventilating and air-conditioning system supporting the count areas is insufficient to maintain thermal conditions in an appropriate comfort range. The ventilation in the Soft Count room does not appear to be able to accommodate the number of people that work in this room (conditions are crowded). Temperatures ranging from 73° - 76° F were measured in the work areas (an acceptable range) and the relative humidity in the work areas was lower than desirable (10-11%). These lower humidity levels and insufficient general ventilation could account for some of the eye and nasal irritation that has been experienced by workers. Exposures to nickel, copper, and zinc during currency counting activities were below recommended limits. The surface sampling results indicate that additional cleaning in the coin counting room is warranted. All measured noise exposures were below recommended limits, however there are opportunities to further reduce noise levels in the Hard Count room. The general ventilation system does not appear to adequately support the Hard Count and Soft Count rooms, particularly the Soft Count room. Relative Humidity levels were low and may account for some of the eye and nasal irritation reported by workers. Tobacco smoke was detected in non-smoking areas indicating that smoke is not being effectively isolated and ventilated. It is possible that the health complaints could be resolved by improving the general indoor environmental quality in the counting area. Recommendations to improve conditions and address ergonomic issues are in the Recommendation section of this report.