Urine samples, 2000.

UNITED KINGDOM - NOVEMBER 22: Photograph taken for the 'Sydney 2000: Drugs Olympics?' exhibition which was held in the Antenna Gallery at the Science Museum, London from June 2000 to February 2001. The exhibition was designed to investigate drug use in sport. Drug use to boost athletic performance continues to blight a wide variety of sports. Substances used are increasingly sophisticated and difficult to detect, a problem exacerbated by the use of �masking agents�, other drugs designed to hide the presence of the performance-relating substance itself. In recent times there have been a number of controversies surrounding the integrity of the testing procedures themselves. (Photo by SSPL/Getty Images)