A number of notable controversies and concerns associated with the 2016 Summer Olympics in Rio de Janeiro, Brazil, emerged which were the subject of public debate and media commentary.
Preexisting issues
Zika virus
An outbreak of the mosquito-borne Zika virus in Brazil raised fears regarding its potential impact on athletes and visitors. Organizers plan to perform daily inspections of Olympic venues to prevent puddles of stagnant water that allow mosquitoes to breed. Zika virus transmission was also attributed to inefficient sewage treatment in the area, and sewage treatment is being improved in preparation for the Games.
There had been numerous calls for the Games to be postponed, warning that the anticipated attendance of 500,000 international visitors could cause the virus to rapidly spread outside of the country. In the first quarter of 2016, there were also more cases of the mosquito-borne Dengue fever than in 2015 alone. Dr. Amir Attaran of the University of Ottawa, writing for the Harvard Public Health Review, noted that Rio had the highest concentration of Zika infections out of all Brazilian states. He argued that the Olympics could result in a "global catastrophe" of Zika outbreaks, and asserted that it was "socially irresponsible" and "ethically questionable" to allow them to continue. On the other hand, it has been argued that the threat of Zika will not be as high during the Games, citing computer models and simulations, as well as the fact that the Games will be held during Southern Hemisphere winter, which is when mosquitoes are least active. The initial outbreak of Zika in Brazil occurred during the winter months, but in Northeastern states near the equator, where there is no winter season throughout the year. Tom Frieden, director of the U.S. Centers for Disease Control and Prevention, stated that "there is no public health reason to cancel or delay the Olympics".
In May 2016, a group of 150 physicians and scientists sent an open letter to the World Health Organization, calling upon them to, according to co-author Arthur Caplan, have "an open, transparent discussion of the risks of holding the Olympics as planned in Brazil". The WHO dismissed the request, stating that "cancelling or changing the location of the 2016 Olympics will not significantly alter the international spread of Zika virus", and that there was "no public health justification" for postponing them.
Many athletes declined to participate in the Games citing concerns over Zika, including Milos Raonic, Tomas Berdych, Simona Halep, Karolína Plíšková, The Bryan brothers, Jason Day, Tejay van Garderen, Branden Grace, Dustin Johnson, Shane Lowry, Rory McIlroy, Marc Leishman, Charl Schwartzel, Angelo Que and Jordan Spieth. As the majority of the athletes that have pulled out were golfers, International Golf Federation president Peter Dawson believed that there was "something of an overreaction" to Zika, stating that "I think I should say now that I don't think it's appropriate for us to discuss individual cases, especially as they're generally decisions that have been taken on health grounds. Speaking collectively though, there is no doubt that the number of withdrawals hasn't shed golf in the best light. We have to accept that. But we do understand why these individual decisions have been taken".
On 2 September 2016, the WHO reported that there were no confirmed cases of Zika among athletes or visitors during the Olympics.
Sanitation
The Guanabara Bay, whose waters were to be used for sailing and windsurfing competitions, is heavily polluted. Among the chief causes of the pollution are uncollected trash fed into the bay via polluted rivers and shanty towns along the coast. Pollution of the Guanabara has been a long-term issue; although officials promised at the Earth Summit in 1992 that they would begin to address the pollution, previous attempts to do so were insufficient. As an aspect of their bid for the Games, Rio once again committed to making efforts towards cleaning the bay. However, some of these proposed initiatives faced budgetary issues.