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Health hazard evaluation report: HETA-2007-0163-3062, investigation of employee symptoms at an indoor waterpark, Great Wolf Lodge, Mason, Ohio.
Chen-L; Dang-B; Mueller-C; Dunn-KH; Almaguer-D; Ernst-JL; Otto-CS III
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 2007-0163-3062, 2008 Jun; :1-53
In March 2007, NIOSH received a technical assistance request from the Warren County Combined Health District (WCCHD) to investigate the cause of symptoms reported by employees at the Great Wolf Lodge (GWL) indoor waterpark resort in Mason, Ohio. Reported symptoms included respiratory symptoms, eye and nose irritation, and skin rashes. In March 2007, we visited the site for the first time. We met with management, WCCHD representatives, and an employee lifeguard representative; toured the facility; and interviewed workers in a private setting. In March and April 2007, we collected area air samples for trichloramine, soluble chlorine compounds, and endotoxin. We also measured air temperature and RH, and administered questionnaires to employees regarding medical, job, and personal history; and work-related symptoms. Water chemistry tests were performed, and water samples were collected for Legionella, fecal coliform bacteria, mycobacteria, endotoxin, sulfites, and sulfates. A review was conducted of the water system and ventilation system designs. The trichloramine concentrations we measured were similar to those found in other indoor swimming pool studies and some were at levels reported to cause mucous membrane irritation. Air endotoxin levels in all pool areas, except the waterfort, exceeded the ACGIH proposed RLV for endotoxin exposure (10 times the background level when symptoms consistent with endotoxin exposure are reported). Water chemistry results met Ohio state standards. No Legionella, mycobacteria, or fecal coliform bacteria were found in any of the water samples collected. Lifeguards had significantly more work-related respiratory symptoms, eye and nose irritation, fever, body aches, and skin rashes in the 4 weeks prior to questionnaire completion than employees who did not work in the indoor pool area. The prevalence of work-related cough and eye irritation among the lifeguards was significantly higher on days when hotel occupancy was high. Ventilation design concerns include the placement of air supply diffusers and return air inlets at heights of 30-80 ft above deck level. This height makes it difficult to provide adequate air movement and mixing at the pool surface and deck levels and creates the potential for short circuiting of supply air to exhaust. This report contains recommendations for decreasing the chloramine exposures thought to cause the reported symptoms, including modification and redesign of the ventilation system to increase air movement at the pool deck level.
Region-5; Chlorine-compounds; Amines; Sulfates; Sulfites; Endotoxins; Humidity; Respiratory-irritants; Respiratory-system-disorders; Eye-irritants; Microorganisms; Bacteria; Skin-irritants; Dermatitis; Ventilation-systems; Engineering-controls; Relative-humidity; Author Keywords: All Other Amusement and Recreation Industries; chloramines; trichloramine; nitrogen trichloride; indoor waterpark; pools; hot tubs; spas; sulfates; sulfites; endotoxin; fecal coliform; relative humidity; Legionella; mycobacteria; cough; respiratory symptoms; rash; eye irritation
Field Studies; Hazard Evaluation and Technical Assistance
NTIS Accession No.
National Institute for Occupational Safety and Health
Page last reviewed: March 11, 2019
Content source: National Institute for Occupational Safety and Health Education and Information Division