Pools, hot tubs and spas occasionally get contaminated with harmful bacteria such as E. coli, Legionella pneumophila, Pseudomonas aeruginosa, Mycobacterium avium, Streptococcus and Salmonella. These bacteria are known to cause serious diseases in humans such as infection of the skin, eyes, ears, hair follicles, intestines and urinary tract.
More serious illnesses are the Legionaires’ Disease and Pontiac Fever acquired from inhaling airborne Legionella cells. This occurs when Legionella becomes airborne by way of aerosol mists produced in spas and hot tubs.
Legionella bacteria are able to survive in low temperatures, but thrive at temperatures between 20oC and 45oC. Legionella cannot survive at temperatures of 60oC and above.