A rule which could have major implications for Alberto Contador’s doping case will be debated this weekend when WADA considers whether a minimum threshold should be introduced for Clenbuterol.
The Spaniard tested positive for the substance during last year’s Tour, and since then has been fighting his case. Cleared by the Spanish national federation, this ruling was appealed by both the UCI and WADA itself, and is due to be held before the Court of Arbitration for Sport in November.
This weekend’s debate will be held in Switzerland, where WADA will decide whether it should stick with its complete ban on the substance. Clenbuterol is a growth promoter which has been illegally used by sportspeople to build strength, but is also known to have been exploited by farmers seeking to bulk up cattle.
The latter problem is most prevalent in South America and China, while in Europe tests have shown that it is very rare.
Tests for athletes have become more sophisticated, meaning that miniscule amounts of substances such as Clenbuterol can now be detected. Contador’s level would not previously have been picked up by doping control labs.
The increased sensitivity of tests is a double edged sword; while it could in theory cause problems with small levels of contaminants in food, as Contador claims is the case, it is also useful in detecting traces of substances that athletes may have used in the past, or may have tried to hide with masking agents.
Professor David Cowan of King’s College London, who heads up anti-doping testing at next year’s Olympic Games, spoke to the BBC on the subject. “Personally, I think that having some threshold would give some more uniformity to the test, but pragmatically we don't want to limit the sensitivity of tests,” he said.
“Having a threshold as we do for many substances is a way to get some uniformity so we don't necessarily detect just one molecule. In any type of forensic investigation, it isn't only the presence but also the circumstances which are important when determining a case.”
Even if WADA were to agree to introduce a threshold level for Clenbuterol, it is unclear if this would necessary lead to the Contador case being dropped. Analysis of the Spaniard’s doping test samples reportedly showed high levels of plasticizers; a test which has been developed but not fully ratified shows a link between this substance and blood transfusions.
WADA has implied that Contador’s case and this test may be connected, but has not made any official statements on the matter. It is understood that it has introduced additional elements to its appeal to CAS, deciding to keep that process separate to the UCI’s own case against the rider, which is based solely on the claims of food contamination.
If it transpires that those additional elements are linked to suspected blood doping, any decision to relax the strict 'no tolerance' for Clenbuterol may not necessarily spell the end of WADA’s action against the rider.