Does modern chemical analysis allow the identification of passive cannabis smokers?

Cannabis continues to be the most widely used drug worldwide. This increases the risk of positive drug tests in individuals with a secondary exposure. For this reason, the aim of the present work was to clarify the possibilities of modern toxicochemical analysis to distinguish the biological samples of passive smokers of cannabis. The algorithm by which drug use is monitored today includes the sequential implementation of screening and evidentiary analytical methods. Through the former, possible drug users are filtered, and through the latter, the reliability of the obtained results is categorically confirmed. Due to its kinetic characteristics, the main psychoactive component of marijuana, Δ9-tetrahydrocannabinol (THC), is sometimes replaced as a target analyte by one of its metabolites. In urine, which is the most frequently studied type of biological matrix, it is practice to determine the amount of non-pharmacologically active 11-nor-9-carboxy-Δ9-tetrahydrocanbinol. It has been established that in passive smokers its concentrations do not exceed 50 ng/mL in drug screening and 15 ng/mL in confirmatory analysis. Alternatively, THC and/or its metabolites can be tested in blood, hair, saliva, and others. The analytical tools of the XXI century allow the identification of individuals exposed to the psychoactive agent THC in a passive way. This does not, however, negate the personal responsibility of each individual to avoid playing the role of a passive smoker.