[Steve Van Doorn]

"Does that mean swimmers would show less spike proteins due to absorption off chlorine?"

I'm a rescue scuba diver and a fairly good swimmer. I've only drank the water when I was in trouble when I had a hard time breathing. Residue from the water is all you would normally take in.

Absorption through the skin would likely be similar to taking a shower with chlorinated water. As warmer water opens pores. Then the chlorine vapor while in the shower can't be good.
Though this chlorine isn't passing through your stomach to produce Chlorine dioxide.

[Melian]