title: A systematic review of passive exposure to cannabis.
abstract: Passive exposure to cannabis smoke may induce effects on behavior and psychomotor skills, and have legal consequences, including the risk of being falsely considered as a cannabis user. This can become a concern, especially in occupational contexts or when driving vehicles. In order to enable a differentiation between a passive and an active exposure to cannabis and to limit the likeliness to be detected positive following passive exposure, this review identified specific biomarkers of passive exposure in urine, blood, oral fluid, hair, and sebum. Out of 958 papers identified on passive exposure to cannabis, 21 were selected. Although positive tests had been observed in all matrices following extremely high passive exposure, some distinctive features were observed in each matrix compared to cannabis active use. More specifically, in everyday life conditions, 11-nor-delta-9-THC-carboxylic acid (THC-COOH) urinary level should be detected below the positivity threshold used to confirm active smoking of cannabis, especially after normalization to creatinine level. Measuring delta-9-tetrahydrocannabinol (THC) and THC-COOH in blood is an appropriate alternative for appraising passive exposure as low and very low concentrations of THC and THC-COOH, respectively, should be measured. In hair, oral fluid (OF) and sweat/sebum emulsion, no THCCOOH should be detected. Its presence in hair argues for regular cannabis consumption and in OF or sweat for recent consumption. The experts should recommend to persons who have to demonstrate abstinence from cannabis to avoid heavily smoky and unventilated environments.
authors.affiliation: Institute for Work and Health (IST), Universities of Lausanne and Geneva, Lausanne, Switzerland. Electronic address: aurelie.berthet@hospvd.ch.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Berthet
authors.affiliation: Unità di Medicina e Psicologia del Traffico, Lugano, Switzerland.
authors.forename: Mariangela
authors.initials: M
authors.lastname: De Cesare
authors.affiliation: University Centre of Legal Medicine, Universities of Lausanne and Geneva, Lausanne, Switzerland; Department of Ambulatory Care and Community Medicine (Policlinique Médicale Universitaire), Lausanne University Hospital (CHUV), Lausanne, Switzerland.
authors.forename: Bernard
authors.initials: B
authors.lastname: Favrat
authors.affiliation: University Centre of Legal Medicine, Universities of Lausanne and Geneva, Lausanne, Switzerland.
authors.forename: Frank
authors.initials: F
authors.lastname: Sporkert
authors.affiliation: University Centre of Legal Medicine, Universities of Lausanne and Geneva, Lausanne, Switzerland.
authors.forename: Marc
authors.initials: M
authors.lastname: Augsburger
authors.affiliation: University Centre of Legal Medicine, Universities of Lausanne and Geneva, Lausanne, Switzerland.
authors.forename: Aurélien
authors.initials: A
authors.lastname: Thomas
authors.affiliation: University Centre of Legal Medicine, Universities of Lausanne and Geneva, Lausanne, Switzerland.
authors.forename: Christian
authors.initials: C
authors.lastname: Giroud
mesh_terms: D015415:Biomarkers / Q000032:analysis; D013759:Dronabinol / Q000031:analogs & derivatives* / Q000032:analysis*; D006197:Hair / Q000737:chemistry; D006801:Humans; D008385:Marijuana Smoking; D012463:Saliva / Q000737:chemistry; D013542:Sweat / Q000737:chemistry; D014028:Tobacco Smoke Pollution
chemical_list: D015415:Biomarkers; D014028:Tobacco Smoke Pollution; C016780:11-nor-delta(9)-tetrahydrocannabinol-9-carboxylic acid; D013759:Dronabinol
keywords: Blood; Cannabis; Hair; Oral fluid; Passive exposure; Urine