Thirteen rowers on the 40-member U.S. team came down with stomach illness at the World Junior Rowing Championships - a trial run for next summer's Olympics - and the team doctor said she suspected it was due to pollution in the lake where the competition took place. The event took place amid rising concerns about the water quality at venues for the Rio de Janeiro Olympics, now less than a year away. The Americans were by far the hardest hit at the regatta that concluded over the weekend, with reports of vomiting and diarrhea.