The swimmers at the outdoor pool in Reiskirchen-Ettingshausen in the Gießen district, suffered respiratory problems, coughing fits and skin irritation due to the high level of chlorine in the pool on Tuesday.
Emergency services were alerted and 30 bathers – many of whom were youngsters – were given treatment at the scene. They were able to go home after.
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A total of eight people were taken to hospital as a precaution, police said.
The pool was closed for the rest of the afternoon following the incident. On its Facebook page, the outdoor pool announced that it would open again on Friday. They apologized and said it was due to a technical fault.