By Lise Alves, Senior Contributing Reporter

RIO DE JANEIRO, BRAZIL – After concerns from the international community related to the dangers that the pollution of the Guanabara Bay and Lagoa would have on athletes competing in aquatic sports in this year’s Olympics in Rio de Janeiro, officials scrambled to find why the water in one of the pools at the aquatic center had turned from blue to green.

Brazil, Rio de Janeiro, Green colored water at diving pool at Rio's Olympic Park is said to be no threat to athletes
Green colored water at diving pool at Rio’s Olympic Park is said to be no threat to athletes, photo internet recreation.

On Wednesday, organizers said that the change in color occurred due to an increase of acidity in the water and poses no risk to athletes.

“A sudden change in alkalinity, this was the reason. PH levels are at the required standard. We treat the two pools at night and alkalinity levels were improved, we expect the color back to blue soon,” executive director of communications of the Rio 2016 Committee, Mario Andrada told reporters during a press conference on Wednesday.

According to Andrada a team of experts was brought in to examine the water and found that a very low concentration of alkaline, leading to the proliferation of microscopic algae which affected the water’s color.

The day before (Tuesday, August 9th) spectators and athletes were stunned to see the sudden change in water color at the pool where the diving competition was occurring.

The difference was even clearer because the water at the pool right next to it, used for water polo competition, continued blue. On Wednesday, however, to the dismay of organizers, not only the water at the diving pool remained green, but the water at the polo pool, which had been clear blue the day before, started to turn green.

FINA (International Swimming Federation) also issued a statement on Wednesday confirming that the water color on any of the pools inside Rio’s aquatic center was a threat to athletes. “FINA can confirm that the reason for the unusual water color observed during the Rio 2016 diving competitions is that the water tanks ran out some of the chemicals used in the water treatment process.”

According to the entity its Sport Medicine Committee conducted tests on the water quality and concluded that there was no risk to the health and safety of the athletes, and ‘no reason for the competition to be affected’.


  1. How on earth could anyone responsible have allowed chemicals to run out at an Olympic competition?? That is just crazy. I fully understand the difficulties facing Rio staging such a huge event in the current climate and after the wonderful opening ceremony and many successfully run competitions I thought it was going well and a credit to the organisers. But running out of chemicals to treat a relatively small pool which the whole world is watching is just absurd.

    I note that pool treatment generally seems to be a perennial problem in Brazil. I visit every January and always see cloudy or slightly green pools, even at big-name resort hotels. Are they trying to save on chemicals? Two years ago I developed a skin infection from a pool at a hotel in Paraty. BY the tie I got home my whole elbow was swollen and it took an injection and two rounds of antibiotics to return to normal. Pool maintenance is not rocket science!!


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