Thanks DrLumen for an accurate statement about what is going on in the pools.
In defense of Sharke, the chloramines in the pool at question come in 3 distinct flavors (egghead chemistry stuff of little concern...) Depends on how aggressive the chlorine can alter the ammonia in the pool. Means how much **** and piss and sweat in the pool relative to the amount of chlorine in there to kill off the filth. Greater density of the ingredients around if you or someone next to you has just emptied bladder or bowels into the closed collective swim space. The macho grade tri amines are definitely suspected as being cancer causing.
Not to worry about dropping dead before you get back to the locker room however.
These chemicals do cause irritation of the eyes and lungs. Like DrLumen said, the smell of chlorine in the pool is not the chlorine additive but the chlorine and ammonia mix byproduct. This can exacerbate asthma or breathing difficulties in prone individuals.
I'd guess that for a healthy individual, the benefit of a good aquatic workout would be greater than the health risk imposed by swimming through chlorinated urine and feces. Most of us swam in public pools and survived to adulthood with little more than red eyes for awhile after.
John