Approximately 6,800 athletes are expected to compete in the Pan American Games, which begins Oct. 14 in Guadalajara, Mexico.
Earlier this year, five Mexican soccer players tested positive for clenbuterol. The Mexico soccer federation cleared the five, saying contaminated meat caused the positive tests.
Last month the World Anti-Doping Agency challenged the Mexico federation's decision and is appealing the case to the Court of Arbitration for Sport in Switzerland.