Air Pollutant Exposures Inside Ice Hockey Rinks: Exposure Assessment and Reduction Strategies
Authors: Brauer M , Spengler JD , Lee K , Yanagisawa Y 
Published: March 2009

The common operation of fuel-powered resurfacing equipment in enclosed ice hockey rinks has the potential for producing poor indoor air quality. In the confined space of an indoor ice rink, the emission of internal combustion engine exhaust is combined with the elevated respiratory ventilation rates of exercising individuals to create a potentially serious health concern. High concentrations of gaseous combustion products may adversely impact the health of rink employees, hockey players, officials, and spectators. The majority of these ice resurfacers are gasoline- or propane-powered internal combustion engines. The operation of this resurfacing equipment over the course of a typical 14 to 18-h operating day can lead to the buildup of elevated concentrations of carbon monoxide (CO) and nitrogen dioxide (NO2). While it has been recognized for some time that high concentrations of CO may be produced in hockey rinks, occasionally leading to toxicity, recent case reports also describe acute respiratory illness among hockey players and spectators as a result of NO2 exposure inside the rink building. Most previous reports of poor indoor air quality inside hockey rinks have been associated with incidents in which resurfacer malfunction produced elevated concentrations of CO or NO2. In contrast, we sought to investigate the range of exposures encountered in typical rinks under normal operation to examine the public health impact of these NO2 exposures.
Accordingly, a survey of 1-week average NO2 concentrations in 70 rinks in the northeastern United States was conducted during the winter season. NO2 concentrations were measured at two locations inside the rink, on the main ice resurfacer, and outdoors. Through questionnaires we also collected information on the physical characteristics of the building (size, ventilation, and so forth), resurfacer use, and records of resurfacer maintenance. The median NO2 level inside the rink was 180 ppb which was more than 10 times higher than the median outdoor concentration. One-week average NO2 concentrations above 1000 ppb were measured in 10% of the rinks. Considering that short-term peak concentrations were likely to have reached 2 to 5 times the measured 1-week averages, our results suggest that NO2 levels were well above short-term (1-h) occupational and environmental air quality guidelines.
In response to the high NO2 levels measured in the survey, subsequent work involved the assessment of potential mitigation strategies, including the attachment of an extended exhaust pipe, limiting the number of resurfacer operations, and use of the rink's air supply and air exhaust systems. Attachment of the exhaust extension was not effective in reducing CO or NO2 concentrations in the rink. Operation of the rink's air supply system and controlling the number of resurfacer and edger operations were partially effective in reducing the air pollutant levels. However, no single reduction method was sufficient to keep the air pollutants below reference limits. Only full operation of the air exhaust system combined with a reduced number of resurfacer operations decreased air pollutants levels below reference limits. These results indicate the dif ficulty of maintaining adequate air quality inside hockey rinks as long as standard gas-or propane-fueled resurfacing equipment is used.