ATLANTA, March 1 (UPI) -- U.S. health officials said the yellow haze that hovered over an ice hockey rink where many were sickened was nitrogen dioxide gas, a combustion byproduct.
A report published by the Centers for Disease Control and Prevention's Morbidity and Mortality Weekly Report said a previously 19-year-old male hockey player was hospitalized Jan. 4, 2011, for sudden onset of cough, shortness of breath and hemoptysis -- coughing of blood -- shortly after a team practice.
The indoor arena had an air monitoring system for carbon monoxide and carbon dioxide, but not for nitrogen dioxide.
"Health investigators found on Jan. 3, 2011, the ventilation system circuit board failed while being serviced, making the ventilation system inoperable. Arena workers had resurfaced the ice using propane-powered equipment and noticed a yellow haze, as did hockey players, coaches and spectators," the report said. "A total of 43 exposed persons were interviewed, of whom 31, 72 percent, reported symptoms consistent with nitrogen dioxide gas exposure. The highest attack rate was among the hockey players. After repair of the ventilation system, no additional cases were identified."
To prevent similar episodes, ice arena operators should ensure ventilation systems and alarms are operating properly and that levels of nitrogen dioxide gas and carbon monoxide are monitored continuously for early detection of increased gas levels, CDC officials advised.