The National Institute for Occupational Safety and Health said they found one pool chemical at levels that could lead to minor irritation. All water chemistry results were within state standards.
The report recommends that Great Wolf Lodge assess its ventilation system to ensure proper air movement.
NIOSH Health Hazard Evaluation Report on Great Wolf Lodge In January 2007 our office received the first complaint of what ended up being a total of 622 individuals reporting symptoms of coughing, eye and nose irritation, respiratory irritation, and skin rashes from patrons at the Great Wolf Lodge (GWL) in Mason, Ohio. These complaints stemmed from visits to GWL from December 2006 through April 2007.
Inspections conducted in the facility in response to these complaints revealed that GWL was in compliance with all Ohio Department of Health and Ohio Department of Agriculture Rules regarding the public swimming pools and water features and they exceeded compliance with the Ohio Basic Building Code with their ventilation system. Based on the reported symptoms we suspected that there might be a chloramines problem; however, an indoor air quality investigation exceeded the technical capabilities of this office.
Because there were also complaints from some of the lifeguards regarding similar symptoms, we submitted a technical assistance request to the National Institute for Occupational Safety and Health (NIOSH) to assist our office in investigating the source of the problem and to recommend corrective action.
This investigation began in March 2007 and the final report was issued yesterday under the title “Investigation of Employee Symptoms at an Indoor Water Park”, Health Hazard Evaluation Report, HETA 2007-0163-3062, Great Wolf Lodge, Mason, Ohio June 2008.
It should be noted that throughout the investigation conducted by our office and NIOSH, Great Wolf Lodge cooperated fully in the investigation, increased their ventilation by 10%, brought in a nationally recognized ventilation expert to evaluate their system to insure it was performing as designed, conducted air sampling and water testing far in excess of any existing standards, and began an education program for their bathers to minimize the formation of chloramines in the water park.
As Great Wolf Lodge worked with our office and NIOSH, they implemented many of the changes being discussed by NIOSH well before the release of NIOSH’s investigation report.
NIOSH’s conclusion regarding employee exposure, who would have had long-term exposure compared to the short-term exposure experienced by any visitors to the water park, is that their review of the ventilation system, relative humidity and trichloramine measurements, the ventilation system at the time of their evaluation may not have been providing adequate capture and removal of chloramines at the pool surface and deck levels.
Additionally, trichloramine concentrations measured were similar to levels found in other indoor swimming pool studies and some were at levels reported to cause irritation symptoms. Trichloramines are a naturally occurring byproduct in chlorinated pools.
NIOSH’s report also provides some recommendations to prevent these types of problems, most of which Great Wolf Lodge has already implemented.
In conclusion, it should be noted, that Great Wolf Lodge was and remains in compliance with all State Codes for water quality, public pool safety, and ventilation standards in Ohio. There have not been any further reported problems with bathers at Great Wolf Lodge, Mason, Ohio experiencing any of the symptoms associated with the December 2006-April 2007 time period.
It is our belief that some of the problems reported by bathers at that time can be attributed to elevated levels of chloramines during high bather load periods causing short term discomfort to less than 1% of the total bathers using the Great Wolf Lodge Water Park. Some people are more sensitive to chlorine and chloramine exposure.
There is no exposure standard for chloramines and the result of the testing completed by NIOSH indicated that some of the levels were in the range that other bathers in other indoor swimming pool environment’s had experienced mucous membrane irritation. Some of the skin rashes can be attributed to long-term exposure to the chlorine in the pool as many bathers were in the water for extended periods of time.
Some of the symptoms can also be attributed to placing 3000 people in a close, warm, and humid environment during cold and flu season. Our office will continue to work closely with the Ohio Department of Agriculture, under whose jurisdiction the water park falls, and with Great Wolf Lodge, to provide a safe and healthy recreational environment at this facility.