Another Dark Day For Track And Field Dylan Martinez / Reuters Tyson Gay of the U.S. reacts after finishing fourth in the men's 100m final during the London 2012 Olympic Games at the Olympic Stadium, Aug. 5, 2012. Track and field has two opportunities to grab global attention: the Olympics, and to a lesser extent, the world championships. Unfortunately for the sport, this year's worlds - which will be held in Moscow from August 10-18 - will be overshadowed by the latest performance-enhancing drug scandal. PEDs have shattered track and field over the last decade. All world-record times carry some skepticism - if he or she clean? - and the latest news won't stop that mindset. On Sunday, American Tyson Gay, who holds the U.S. record in the 100 and won the 100 and 200-meter races at nationals last month, tested positive for a banned substance. Neither Gay or U.S. Anti-Doping Agency head Travis Tygart have revealed the identity of the drug. "I don't have a sabotage story," Gay told the Associated Press. I don't have anything to say to make it seem like it was a mistake or it was in USADA's hands, someone playing games. I don't have any of those stories. I basically put my trust in someone and I was let down. Gay said he'll withdraw from the world championships. On Sunday, world also came down that two top Jamaican sprinters, former 100-meter world record holder Asafa Powell and Sherone Simpson, who was won an Olympic gold and two silvers, also failed drug tests. Both were more adamant than Gay that they did nothing wrong: Powell called for an investigation to find out how oxilofrine, a stimulant, got into his system. Simpson tested positive for the same stimulant and said she "would not intentionally take an illegal substance of any form into my system." A month earlier, Jamaican gold medalist Veronica Campbell-Brown, tested positive for a banned diuretic; her agent has said Campbell-Brown does not accept "guilt of willfully taking a banned substance." (MORE: Who's A Better Athlete? Usain Bolt Or Decathlete Ashton Eaton?) Rashalee Mitchell, a social sciences lecturer at the Jamaica campus of the University of the West Indies, told the Associated Press that the Jamaican scandals are tainting "our proud and long-standing reputation of producing strong, excellent, raw, homegrown talent that has excelled on the world stage without any drug-related enhancement." Jamaica, and the world, can take some comfort: Usain Bolt was not among those who tested positive for PEDs. At this point, Bolt is track and field royalty; his participation in next month's worlds will make global headlines. But if a bombshell were to drop that Bolt had tested positive for something - and let us emphasize that this is just a big if - would it be all that shocking? Track fans have become accustomed to these types of revelations. And that says something sad about the sport. MORE: The $400,000 Racing Pigeon Named After Usain Bolt