The European Monitoring Centre for Drugs and Drug Addiction, describing the situation as an “apparent heroin drought” in its 2011 report, assesses the situation at least in part resulting from a drop in the Afghan opium production to 3,600 tonnes in 2010 - half the level reached in the previous year
The crop in Afghanistan was hit by poppy blight in the spring of 2010, a possible factor in decline, although police reports suggest that heroin made from Afghan opium may not appear on the European drug markets until about 18 months after harvest.
Unfavourable weather conditions may also have played a role, as may have a fungal infection that affected opium fields in the major poppy-growing provinces, particularly Helmand and Kandahar. Additionally, heroin destined for western Europe has increasingly been diverted to the Russian market, although Russia also appears to be undergoing a heroin shortage. A third explanation for the drought may relate to police actions disrupting trafficking, particularly after the dismantling of Turkey-UK wholesale heroin networks.
The report concludes that in the end, it is likely that “a combination of some of these factors has played a role in disrupting the supply of heroin to Europe, causing severe shortages in some markets.”
http://euobserver.com/851/114288