In 2015, it was found that because of open drainage and severe pollution, the incidence of "disease-causing viruses" in Rio's waterways was measured to be "1.7 million times the level of what would be considered hazardous on a Southern California beach".
2015年，据发现由于开放排水和严重的污染，里约水道“致病病毒”发病率被检测出是“南加州海滩危险程度的170万倍”。