Twenty-five pool swimmers were recently poisoned by a cloud of chlorine gas rising from the water, hospitalizing several children as young as 3 in northern Italy.
The gas seriously affected four swimmers and also poisoned nine children between the ages of 3 and 6 who were at the Monti Lessini Sports Center for a swimming lesson, The U.S. Sun reported. The most-affected swimmers were taken to several different regional hospitals, and others were taken in minibuses to get medical attention.
Italy’s national fire and rescue service, Vigili del Fuoco, responded to the incident, which occurred March 17, and conducted nuclear, biological, chemical, and radiological surveys, according to a post on Twitter.
Investigations indicated that the incident was caused by pool workers miscalculating how much chlorine was needed to sterilize the pool. The workers put in too much chlorine, resulting in gas rising from the surface of the water, according to the Sun.
Chlorine in powder or liquid form is added to pools to kill bacteria. It usually does not form gas clouds unless there is an extremely large amount of it or it is mixed with certain chemicals, including household substances like hydrochloric acid or ammonia, according to Live Science.
Chlorine gas exposure can result in blurred vision; burning in the eyes, nose, throat, and lungs; difficulty breathing; vomiting; and coughing up white- or pink-tinged fluid, according to the Centers for Disease Control and Prevention.
A similar incident came in 2021 at Texas’ Six Flags Hurricane Harbor Splashtown. In that case, 31 people were hospitalized when chemicals, believed to be bleach or sulfuric acid, leaked from a system that maintained a pool’s pH balance, Insider reported.
Dozens of people were reportedly decontaminated with water from a fire truck house, 55 of whom refused to be transported to a hospital.
Authorities did not suspect intentional contamination.