Toxicology testing performed by the FAA Bioaeronautical Research Sciences Laboratory, Oklahoma City, Oklahoma, for the pilot was negative for carbon monoxide and cyanide. The testing identified ethanol at 0.059 gm% in urine, 0.037 gm% in muscle, 0.036 gm% in brain, and 0.033 gm% in blood (unknown source). In addition, 10.1 ng/ml of tetrahydrocannabinol (THC, the primary psychoactive substance in marijuana) and 13.1 ng/ml of 11-carboxytetrahydrocannabinol (THC-COOH) was identified in blood. THC- COOH was also identified in urine.
Ethanol is the intoxicant commonly found in beer, wine, and liquor. It acts as a central nervous system depressant. The effects of ethanol on aviators are generally well understood; it significantly impairs pilots' performance, even at very low levels. Title 14 CFR section 91.17 (a) prohibits any person from acting or attempting to act as a crewmember of a civil aircraft while having 0.040 gm/dl or more ethanol in the blood. Because ingested alcohol is distributed throughout the body, levels from different post mortem tissues are usually similar. Ethanol may also be produced in body tissues by microbial activity after death.
Marijuana is a psychoactive drug with therapeutic levels as low as 0.001 ug/ml. According to NHTSA's Drugs and Human Performance Fact Sheets, "It is difficult to establish a relationship between a person's THC blood or plasma concentration and performance impairing effects. Concentrations of parent drug and metabolite are very dependent on pattern of use as well as dose. THC concentrations typically peak during the act of smoking, while peak 11-OH THC concentrations occur approximately 9-23 minutes after the start of smoking. Concentrations of both analytes decline rapidly and are often < 0.005 ug/mL at 3 hours." A detailed report of the toxicological results is included in the public docket associated with the investigation.
Just the facts, do the math and draw your own conclusions.