Labs that test athletes for evidence of doping could be letting cheaters slip through, the BBC reports. Negative results for samples an anti-doping scientist deems suspicious have raised doubts about the fairness of the field at next month's Olympic Games. With some versions of a blood-boosting drug available cheaply and nearly undetectable, experts fear many endurance athletes will cheat.
Erythropoietin, or EPO, helps boost the body's production of red blood cells, increasing blood oxygen levels. When authorities introduced a new test in 2000, a number of suspected false positives sparked athletes to challenge their results, causing the World Anti Doping Agency to change the test criteria. But one scientist says the new rules are too lax to catch most dopers.