According to Olympics historian Bill Mallon, more than 140 athletes were banned or disqualified, including 42 medallists (13 of which were gold). Nearly half were caught using retrospective testing. Because doping has become so much a part of the Olympics, one wonders whether the inevitable doping scandals in Tokyo will be as earth-shattering as they once were, or whether the public will merely shrug. How many positive tests come back every year The anti-doping industry has become a lot better at what it does since the establishment of the World Anti-Doping Agency (WADA) in 2000 and the introduction of the World Anti-Doping Code (WADC) in 2001. Revisions to the WADC came into force in 2009, 2015 and 2021.