Researchers determine whether the controversy over chlorinated water causing childhood asthma is due to citation bias in the current scientific literature.

Childhood asthma is a common chronic disease. Swimming is an accepted way to relieve symptoms, which include shortness of breath, wheezing, and coughing. However, a study challenging this recommendation was published in 2003.

It suggested that chlorinated water actually increased children’s risk of developing asthma. When chlorine in the pool reacts with urine or sweat, it forms a chemical called trichloramine that can potentially cause respiratory problems in sensitive individuals. Further investigations into this claim have yielded conflicting results; therefore, the debate on whether chlorinated water affects childhood asthma is ongoing.