Urine-indicator dye is a mythical substance that is supposed to be able to react with urine to form a colored cloud in a swimming pool or hot tub, thus indicating the location of people who are urinating while they are in the water.[1][2] A 2015 report from the National Swimming Pool Foundation called this "the most common pool myth of all time", with nearly half of Americans surveyed by researchers believing that the dye existed.[3]

Urine is difficult to detect, as many of the naturally occurring compounds within urine are unstable and react freely with common disinfectants, such as chlorine, creating a large number of disinfection by-product (DBP) compounds from the original organic chemicals in urine.[4][5]

Rumours of the origin of urine indicator-dye go back at least as far as 1958,[1] and the story is commonly told to children by parents who do not want them to urinate in the pool.[3] A 1985 biography of Orson Welles describes him using such a dye as part of a prank in 1937.[1][6]

References edit

  1. ^ a b c Mikkelson, Barbara (December 14, 2000). "Piscine of the Crime". Snopes. Retrieved September 18, 2012.
  2. ^ Hannah Devlin (1 March 2017). "How much pee is in our swimming pools? New urine test reveals the truth". The Guardian. Retrieved 6 June 2022.
  3. ^ a b O'Neil, Lauren (25 June 2015). "Pee, not chlorine, causes red eyes from swimming pools: CDC". CBC News. Retrieved 26 June 2015.
  4. ^ Lindsay K. Jmaiff Blackstock; et al. (1 March 2017). "Sweetened Swimming Pools and Hot Tubs". Environmental Science & Technology Letters. 4 (4): 149–153. Bibcode:2017EnSTL...4..149J. doi:10.1021/acs.estlett.7b00043.
  5. ^ Dr Karl Kruszelnicki (2010). Curious and Curiouser. Pan Macmillan. pp. 203–207. ISBN 9781742624266.
  6. ^ Sally Magnusson (2011). Life of Pee; The Story of How Urine Got Everywhere. Aurum Press. p. 143. ISBN 9781845138011.