What should swimmers avoid to help prevent the introduction of Giardia into pools?

Swimming when sick is the correct choice because individuals who are experiencing gastrointestinal issues, such as diarrhea caused by Giardia or other pathogens, can shed these organisms into the water. Giardiasis is a parasitic infection that can be transmitted through contaminated water. When an infected person swims, they may introduce Giardia into the pool, putting other swimmers at risk of infection.

By avoiding swimming when sick, especially with gastrointestinal symptoms, swimmers help to maintain the hygiene and safety of the swimming environment, thereby reducing the likelihood of Giardia and other pathogens being introduced into the water.

The other options do not directly address the risk of transmitting Giardia. Swimming in the morning has no specific effect on the risk of infection. Eating before swimming, while possibly affecting comfort levels, is not linked to Giardia transmission. Wearing sunscreen is important for skin protection but does not relate to the prevention of Giardia contamination.