The Civil Aerospace Medical Institute�s toxicology laboratory receives biological specimens from more than 90% of all fatal aviation accidents that occur in the United States and its territories. As a part of the routine analysis of pilot specimens, the laboratory tests all cases for the presence of marijuana (cannabis). The National Institute on Drug Abuse (NIDA) and the Office of National Drug Control Policy (ONDCP) reported a 1.5-fold increase in the delta-9-tetrahydrocannabinol (THC) content of street cannabis seizures from1997-2001 to 2002-2006.