Today we hit a record high where I live. In fact, as I write this, it is still in the triple digits. I could use a little cooling dip in a pool. If you are suffering from the heat and are seeking some relief, you may want to be advised of some stats regarding pool water.
According to studies done by the CDC, you are more likely to get sick from pathogens in pool water than a natural body of water. Their report discovered that some pathogens have become resistance to chlorine and it is these pathogens which have given a rise in the reported cases of water borne infections. Based on the study, you are almost 3.5 times more likely to get infected in treated water than a natural source.
They found that the source of most of these pathogens was human poop. The pathogen is introduced into the water from an infected person, from there anyone whom either inadvertently drinks the water or inhales some of the water mist.
The main pathogen found was Cryptosporidium, this is a parasite that lives in animal intestines and spreads by shedding itself from feces into water sources. Next was Norovirus which is spread through vomit and feces. As you can see the main factor of transmission is poop.
Chlorine can control many pathogens but Cryptosporidium can survive in chlorinated water for more than a week.
The most likely place for outbreaks were from hotel pools and it was even more likely from hotel hot tubs or spas. The heated water is more conducive for the growth of pathogens. Hotels were followed by public pools.