What does chlorination help prevent in a pool?

Chlorination is a crucial process in maintaining pool hygiene and safety. It primarily serves to prevent algae growth, which can lead to murky water and slippery surfaces, making the pool unpleasant and unsafe for swimmers. Chlorine is effective at killing bacteria, viruses, and other pathogens that can cause waterborne illnesses. This aspect is vital for protecting swimmers from infections and diseases that may be transmitted through contaminated water. By ensuring proper chlorination, pool operators can maintain a clean and safe swimming environment, thereby promoting the health and enjoyment of all users.

The other options do not accurately capture the primary purpose of chlorination. High water temperature is influenced by environmental conditions and heating systems, while bad odors can arise from insufficient sanitation but are not the primary concern addressed by chlorination. Overcrowding is related to the number of swimmers and not influenced by chemical treatment. Thus, chlorination's main role centers around preventing biological contaminants, making it essential for public health in swimming pools.