During the Under-17 FIFA World Cup held in Mexico in July, 109 of 208 soccer players tested positive for clenbuterol, according to a revelation by the World Anti-Doping Agency (WADA).

Some farmers in Mexico still illegally use clenbuterol for bulking up cattle even though it is abanned substance that can cause an increase in aerobic capacity.

WADA issued a statement asking all athletes in Mexico to “exercise extreme caution with regards to what they eat and where they eat.”