Cannabis use is on the rise with higher and higher potencies of marijuana being cultivated. Current legislatures make it easier, and legal, for users to use, especially around nonusers. When such second-hand smoke occurs in poorly ventilated confinements, nonusers may inhale some of the smoke, resulting in absorption of cannabinoids. Some degree of intoxication may occur but most importantly, detectable levels of the drug in blood and urine. Often screening is used by employers, law enforcement agencies, physicians and substance abuse providers. Clinicians hence need to be mindful of such factors when patients deny use despite positive tests. Here we review available evidence, with emphasis on current data based on today’s trends.
Clinical background: “I have not smoked marijuana since before I was drafted” 23 year-old NFL player Josh Gordon stated as his explanation for testing positive above the 15 ng/mL THC threshold the NFL considers a failed test. In his appeal he stated he was around individuals using marijuana. His “A” sample tested at 16 ng/mL and his “B” sample tested at 13.63 ng/mL. The two should be consistent since it comes from the same specimen. His legal team was able to dispute the results and reduce his sentence to 8 months as he was the “victim of breathing second hand smoke” (ESPN, 2014).