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Abstract

Increased cannabis potency has renewed concerns that secondhand exposure to cannabis smoke can produce positive drug tests. A systematic study was conducted of smoke exposure on drug-free participants. Six experienced cannabis users smoked cannabis cigarettes (5.3% THC in Session 1 and 11.3% THC in Sessions 2 and 3) in a sealed chamber. Six non-smokers were seated with smokers in an alternating manner. Sessions 1 and 2 were conducted with no ventilation and ventilation was employed in Session 3. Non-smoking participant specimens (collected 0–34 h) were analyzed with four immunoassays at different cutoff concentrations (20, 50, 75 and 100 ng/mL) and by GC-MS (LOQ = 0.75 ng/mL). No presumptive positives occurred for non-smokers at 100 and 75 ng/mL; a single positive occurred at 50 ng/mL; and multiple positives occurred at 20 ng/mL. Maximum THCCOOH concentrations by GC-MS for non-smokers ranged from 1.3 to 57.5 ng/mL. THCCOOH concentrations generally increased with THC potency, but room ventilation substantially reduced exposure levels. These results demonstrate that extreme cannabis smoke exposure can produce positive urine tests at commonly utilized cutoff concentrations. However, positive tests are likely to be rare, limited to the hours immediately post-exposure, and occur only under environmental circumstances where exposure is obvious.

Introduction

Cannabis is the most widely produced and illicitly consumed drug globally. The number of cannabis users has been estimated to be as high as 224 million worldwide, and prevalence of use has remained stable in recent years (1). Over the last decade, indoor cultivation of cannabis has proliferated. Increased indoor growing has been mirrored by an increase in shops and Internet sites that provide information, supplies, equipment and seeds for production. The increased support system for cannabis cultivation together with availability of high-quality seeds has greatly expanded access to high-yielding and highly potent cannabis varieties (1). These plants have high levels of Δ9-tetrahydrocannabinol (THC), the primary cannabinoid responsible for psychoactive effects, and, most commonly, negligible levels of cannabidiol (CBD) and other trace cannabinoids that may have therapeutic potential and may counteract some of the effects of THC (2). Use of cannabis preparations containing high potency THC/low CBD cannabinoid ratios has been linked to a number of putative outcomes (3) including increased risk of psychosis (4) and cannabis dependence (5).

Cannabis terminology varies considerably and numerous terms are in use referring to similar or related cannabis products. The term ‘marijuana’ is generally used to refer to the Cannabis plant (leaves, stems, seeds and flowering tops); whereas, the term ‘sinsemilla’ refers to the flowering tops of unfertilized female plants with no seeds. Globally, two main products are produced from cannabis: cannabis herb and cannabis resin. Cannabis resin, also known as ‘Hashish’ is composed of the resinous parts of the flowering tops of cannabis and is mixed with some plant particles and shaped into a variety of forms, e.g., balls, sticks or slabs. ‘Hash oil’ is a liquid or semi-solid concentrated extract of cannabis plant material.

Cannabis herb is produced and consumed in almost all countries of the world, whereas cannabis resin is produced primarily in North Africa, the Near and Middle East and South-West Asia (6). More recently, there has been a proliferation of alternative cannabis preparations and routes of administration with the advent of more relaxed laws regarding cannabis use and the introduction of a commercial market in some areas. These include various forms of cannabis extracts and oils sold as ‘dab’, ‘wax’, ‘shatter’ and a multitude of cannabis-infused food products (e.g., brownies, candy, butter, granola, beverages), commonly referred to as ‘edibles'. Cannabis is often consumed for the psychoactive and physiological effects produced following use including heightened mood or euphoria, relaxation and an increase in appetite, though the use of cannabis for purported medical/health benefit has gained prominence in the past several decades.

THC is present in cannabis herb preparations as THC and as carboxylic acid precursor molecular forms (precursor acids referred to as Δ9-tetrahydrocannabinolic acid A and Δ9-tetrahydrocannabinolic acid B). The structures of THC and the related precursor acids (THCA-A and THCA-B) are shown in Figure 1. The precursor acids present in cannabis herb should not be confused with the two key human metabolites [11-hydroxy-Δ9-tetrahydrocannabinol (11-HO-THC) and 9-carboxy-11-nor-Δ9-tetrahydrocannabinol (THCCOOH)] produced through metabolism of THC (also shown in Figure 1). Decarboxylation of the precursor THC acids, THCA-A and THCA-B, in cannabis herb occurs during storage, upon heating (e.g., smoking), or under alkaline conditions. The end result of decarboxylation of either acid is the formation of THC (7). Consequently, potency estimates of THC in cannabis herb products are usually expressed as total THCtot (combination of THC, and THCA-A and THCA-B).
Figure 1.
Molecular Structures of THC, THCA-A, THCA-B, 11-HO-THC and THCCOOH.
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Molecular Structures of THC, THCA-A, THCA-B, 11-HO-THC and THCCOOH.

The shift in cultivation practices over the last 30 years toward production of higher potency THC cannabis with negligible levels of CBD has raised concerns that current cannabis is ‘somehow a different drug than that consumed in previous decades' (3). Indeed, the THC potency of confiscated cannabis in the US was 2.83% for marijuana and 7.28% for sinsemilla in 1985 (8). THC potency of federal seizures increased steadily over the ensuing years, reaching 6.73% for marijuana and 16.19% for sinsemilla in 2012, with the average potency for all cannabis types being 13.19% (9).

Given these consistent potency increases, the possible impact of higher potency cannabis on various drug-testing programs prompted renewed study and evaluation. Concerns have been expressed for decades that a non-smoker in the vicinity of cannabis smokers are exposed, in much the same way as non-smokers are exposed to tobacco smoke, to vaporized constituents of cannabis. A variety of studies have documented the extent of secondhand cannabis smoke exposure to non-smokers under varying condition such as enclosed unventilated rooms [six non-smokers exposed to 16 smoked cannabis cigarettes, 2.8% THC (10–12); a single non-smoker in close proximity to four smokers smoking 0, 0.86, 1.54 or 1.83% THC (13); four non-smokers exposed to six smokers smoking a cannabis cigarette containing 17.2 mg THC (∼1.5% THC) (14); two or three non-smokers exposed to four smokers smoking a cannabis cigarette containing 26.2 mg (∼2.6% THC) (15); and three non-smokers exposed to four cannabis cigarettes containing 27 mg THC (∼2.7% THC) (16)], non-smoker exposure to hashish smoking (17), exposure in a small, closed car in which five non-smokers were exposed to three smokers smoking 1.5% THC cannabis or two smokers smoking 1.5% THC hashish cigarettes (18) and exposure in a non-ventilated room or medium-sized station wagon to 2.5% THC or 2.8% THC cannabis cigarettes (19).

Two more recent exposure studies have been conducted with higher potency cannabis cigarettes. In one study, four non-smokers were exposed to cannabis smoke generated by four smokers who consumed a single cannabis cigarette containing either 5.4% or 10.4% THC cannabis in an unventilated eight-passenger van (20). The second study was conducted as a field experiment in a ventilated coffee shop (establishment where cannabis and hashish can be openly consumed) in the Netherlands (21). In this study, eight non-smokers remained in the shop for 3 h in the presence of numerous smokers who consumed cannabis primarily by smoking, but some individuals used hashish pipes or water pipes. The exact cannabis potency, number of cigarettes, or amount of cannabis consumed in this study is not known. As with the prior studies, the two studies involving high-potency cannabis exposure to non-smokers resulted in the detection of THC and metabolites in urine, blood and oral fluid specimens collected from non-smokers after exposure.

The goal of the current study was to extend research involving high-potency environmental cannabis smoke exposure (commonly referred to as ‘passive exposure’) to non-smokers. Specifically, the study was designed to ascertain the effects of cannabis potency and room ventilation on both pharmacokinetic and pharmacodynamic outcomes when non-smokers were exposed to concentrated cannabis smoke. Urine and other biological fluids and tissues were collected before and after smoke exposure to determine if exposure under any of these conditions would produce positive drug tests based on commonly used drug-testing standards. This report provides a detailed description of the experimental conditions employed in the study and provides complete initial screening and confirmatory data derived from urine specimens.

Experimental

Participants

Volunteer participants were recruited through newspaper advertisements, flyers posted on campus and community bulletin boards and word-of-mouth. Two types of volunteers were recruited: (i) current cannabis users (self-reported use of cannabis at least two times per week during the prior 90 days) who were not currently trying to quit; and (ii) healthy volunteers who had a history of lifetime cannabis exposure, but had not used cannabis or other illicit substances within the previous 6 months (self-report). Current cannabis users were required to test positive for cannabis (>50 ng/mL THCCOOH) and negative for recent use of other commonly used psychoactive substances (amphetamines, benzodiazepines, cocaine, MDMA, opioids, PCP and alcohol) at the screening visit and upon admission to the research unit for each experimental session. Non-smokers were required to test negative for all of the above substances at screening and at admission to experimental sessions. Only non- or minimal tobacco users were enrolled; no tobacco use was permitted during study participation.

Eight current cannabis users participated in three experimental cannabis smoking sessions. The eight subjects (three females and five males) had an average [standard deviation (SD), range] age of 29 (6, 24–40) years, weighed an average of 75 (20, 50–108) kg and had an average body mass index of 25.6 (5.1, 20.3–34.2). These eight subjects self-identified their race/ethnicity as follows: four White, non-Hispanic, two Black or African American, one Hispanic or Latino and one as Middle Eastern (Turkish). The smokers self-reported an average of 12 (7, 2–25) years smoking cannabis. They reported an average of 28 (2, 25–30) days of cannabis use in the previous month and consumed an average of 1.5 (2, 0.4–5.2) grams of cannabis per day. The 18 non-smoker participants (nine females and nine males) had an average age of 28 (7, 20–45) years, weighed an average of 74 (12, 55–98) kg and had an average body mass index of 24.7 (3.6, 18.7–33.0). These subjects self-identified as follows: 12 White, non-Hispanic, three African American, two Hispanic or Latino and one Asian.

To the extent possible, conditions were standardized across sessions. Consequently, the six cannabis smokers who participated in Session 1 were invited to continue their participation in Sessions 2 and 3. Four smokers (2M/2F) participated in all three sessions. Two smokers (1M/1F) participated in two sessions and two (2M) participated in a single session. Each of the 18 non-smoking subjects participated in only a single session.

Written informed consent was obtained prior to study participation. The study was approved by the Johns Hopkins Medicine Institutional Review Board and conducted in accordance with the ethical standards of the Helsinki Declaration. All subjects were compensated for their participation.

Chamber construction and layout

A specially designed smoking chamber, made of plexi-glass walls with aluminum supports and measuring 10 ft. × 13 ft. (3.05 m × 3.96 m) with a 7 ft. (2.13 m) ceiling, was constructed for this experiment. It was situated in a larger room that allowed direct observation of all parts of the chamber from three sides. The door to the exposure chamber was also constructed of plexi-glass and aluminum and was fitted with magnets that ran the entire perimeter to create a seal when closed. The door remained closed during each session with two exceptions. One non-smoker smoker (Session 2) and one smoker (Session 3) were allowed a brief bathroom break that lasted ∼5 min. Consequently, the door was opened briefly for exit and entry in those sessions. A metal/plastic utility table (30 in × 6 ft.) was located in the center of the chamber and 12 metal/plastic folding chairs were situated equidistant around the table. During each exposure session, six smokers and six non-smokers were seated in alternate seating positions around the table.

All participants donned disposable paper clothing including booties over their own clothing before entering the experimental chamber for each session. Smokers also wore disposable head coverings to prevent deposition of cannabinoids on their hair during the session. Non-smokers did not wear head coverings because deposition of cannabinoids on hair during naturalistic secondhand exposure might affect hair drug test results, a secondary study outcome. All participants were supplied with goggles for use as needed for reduction of eye irritation from the smoke. During each session, participants remained in their assigned seats and played games, conversed, or engaged in other activities (e.g., listened to music, used cell phone). Smokers were allowed to drink from bottles of water (supplied at the start of the session). Non-smokers were not allowed to eat or drink during the session or after the session until after the first oral fluid specimen was collected. As a safety measure, pulse oximeter readings were collected pre-session and at 15-min intervals during each session to ensure that an adequate oxygen supply was maintained within the chamber.

Cannabis cigarettes

Cannabis for research purposes was obtained through the US federal drug supply program. Two types of Mississippi-grown cannabis with varying cannabinoid content were supplied for the study and were characterized and rolled into cigarettes by staff at Research Triangle Institute, International. The lower potency cannabis cigarettes were machine rolled and were 85 mm in length × 25 mm circumference and weighed a mean weight (SD) of 0.92 (0.06) g/cigarette; the cigarettes had an assayed mean content of cannabinoids as follows: 5.3% (0.48%) total THC; 0.01% (0.0%) CBD and 0.35% (0.04%) cannabinol (CBN). The higher potency cigarettes were hand-rolled and were 70 mm in length (24.5 mm) and had a mean weight (SD) of 1.0 (0.04) g/cigarette; the cigarettes had an assayed mean content (n = 12 for THC; n = 4 for other cannabinoids) of cannabinoids as follows: 11.3% (0.29%) total THC; 0.08% (0.12%) CBD and 0.76% (0.06%) CBN.

Experimental cannabis exposure conditions

Three experimental cannabis sessions were conducted at weekly or greater intervals. Cannabis exposure sessions lasted 1 h, during which smokers consumed cannabis ad-libitum in the presence of non-smokers inside the closed chamber. The primary goal of these sessions was to conduct a pharmacokinetic evaluation of cannabinoids in biological fluids of non-smokers following extreme exposure to secondhand cannabis smoke. Across the three experimental sessions, cannabis potency and room ventilation conditions were manipulated: Session 1 was conducted without air ventilation and cannabis cigarettes containing 5.3% THC were smoked; Session 2 was conducted without air ventilation and cannabis cigarettes containing 11.3% THC were smoked; Session 3 was conducted with active air ventilation comparable to home air-conditioning (11.2 air changes per hour) and cannabis cigarettes containing 11.3% THC were smoked. Each smoker received a pre-weighed individual supply of cannabis cigarettes at the start of each session, and residues and unused portions were collected for weighing at session end.

Experimental procedures following cannabis smoke exposure

At the end of each 1-h cannabis exposure session, participants exited the room and immediately discarded their disposable clothing and washed their hands and face with soap and water. After drying, they proceeded to a cannabis-free room (investigative area) for participation in specimen collections and behavioral and physiological assessments.

Urine, whole blood and oral fluid specimens were collected prior to each session (baseline) and at timed intervals following each session. Coincident with biological specimen collection, vital signs (heart rate, blood pressure), subjective ratings of intoxication and measures of cognitive performance were also obtained. Hair specimens were collected before and after each session from non-smokers. A single pre-study baseline hair specimen was collected from each cannabis smoker and an additional hair specimen was after Session 1 (or subsequent session for smokers who did not participate in all 3 sessions). Experimental measures were obtained every 30 min for the first 2 h, hourly during hours 2–4 and every 2 h during hours 6–8. Smokers were discharged after the 8-h post-exposure time point. Non-smokers remained in the study under supervision over-night and biological specimens and pharmacodynamic measures were obtained through the 34-h post exposure time point. Assessments and outcomes, other than urine testing results, will be reported elsewhere.

Urine collections

Baseline urine specimens were collected ∼1 h prior to each cannabis session. Following the end of each 1-h cannabis exposure period (designated zero time), participants were asked to void at 0.25, 1, 2, 3 and 4 h. Thereafter, urine specimens were pooled for each subject for the following time intervals: 4–6, 6–8, 8–10, 10–12, 12–22, 22–26, 26–30 and 30–34 h. If multiple specimens were produced by an individual during a pool period, they were combined into an individual pool. Each participant was asked to empty their bladder at the end of each pool period for inclusion in that period. No mixing of specimens between participants occurred.

Because of the logistics involved in collecting multiple types of measures from 12 participants, the exact timing of early specimen collections was somewhat variable; consequently, all specimen times should be considered as nominal values (i.e., ±10 min).

Urine specimens were collected in clean, plastic containers labeled with the participant's identification number, date and collection time. Specimens to be pooled were transferred to a labeled plastic pooling vessel and kept refrigerated during the collection period. The volumes of each individual specimen (first 4 h) and of each pooled sample were measured and two aliquots (minimum of 30 mL each) of each were transferred to polypropylene bottles (bottles ‘A’ and ‘B’). If the specimen volume was <60 mL, the specimen was divided into aliquots of approximately equal volume. All aliquots were stored frozen (≤−20°C) and shipped frozen by overnight express to a designated laboratory for analysis.

Analytical methods

Initial analyses of urine specimens were conducted by Clinical Reference Laboratory (CRL), Lenexa, KS. Bottle A specimens were thawed and aliquots were analyzed by immunoassay and gas chromatography–mass spectrometry (GC–MS). Initial analyses of Bottle A specimens by immunoassays were conducted according to manufacturer's procedure with the Microgenics DRI assay on a Bayer ADVAI 2,400 analyzer for cannabinoids in urine at both 20 ng/mL and 50 ng/mL cutoff concentrations. Creatinine was determined with Siemens modified Jaffe reagent. Specific gravity was determined with a Rudolph J57 refractometer. Determinations of pH were made with Axiom pH reagents (Axiom Diagnostics, Tampa, FL, USA).

THCCOOH concentrations were measured by a current, validated GC-MS method by CRL. Briefly, 40 ng/mL of internal standard (THCCOOH-d9, Cerillant Corp., Round Rock, TX) was added to 1 mL of specimen and the sample was hydrolyzed with 0.2 mL of 5N NaOH. After hydrolysis, 1.5 mL of glacial acetic acid (pH 4) was added and THCOOH was extracted with a solid phase column (3 mL J-65 cation exchange, Biochemical Diagnostics, Edgewood, NY, USA). The column was eluted with 1.5 mL of n-butyl chloride/triethylamine (80/20, v/v) and the eluate was evaporated and derivatized with bistrimethylsilyltrifluoroacetamide (BSTFA). The specimen was transferred to an injection vial and analyzed on an Agilent 5,975 GC/MS. Ions (m/z) monitored were 380 and 479 for the internal standard and 371, 473 and 488 for THCCOOH. The calibration standard (single point calibration) contained 15 ng/mL of THCCOOH and 40 ng/mL of THCCOOH-d9. Four controls (negative, 6 ng/mL, 18.5 ng/mL, pooled positive urine for hydrolysis control) were assayed with each batch. The method had a limit of detection (LOD) and limit of quantification (LOQ) for THCCOOH of 0.75 ng/mL and an upper limit of linearity (ULOL) of 600 ng/mL. Specimens with concentrations ≥ULOL were diluted to provide accurate quantitation. Criteria for acceptance of results included the following: retention times of analyte and internal standard within ±2% of the calibrator; ion ratios within ±20% of the calibrator; and positive control concentrations ±20% of established concentrations.

Following analyses of Bottle A by CRL, Bottle B specimens were thawed for additional immunoassay determinations, aliquoted, and frozen aliquots were immediately shipped to three additional laboratories. Bottle B aliquots were sent to selected laboratories with differing types of immunoassays. They were analyzed as follows (laboratory, location, immunoassay type, cutoff concentrations): CRL, Lenexa, Microgenics DRI, 20 ng/mL, 50 ng/mL; MEDTOX Laboratories, St Paul, MN, KIMS, 20 ng/mL, 50 ng/mL; MetroLab-Legacy Laboratory Services, Portland, OR, EMIT II, 20 ng/mL, 50 ng/mL; and One Source Toxicology Laboratory, Pasadena, TX, CEDIA, 20 ng/mL, 50 ng/mL, 75 ng/mL, 100 ng/mL.

Sensitivity, specificity and agreement

The sensitivity, specificity and agreement of the immunoassays for detection of cannabinoids in urine were calculated by comparison of the qualitative immunoassay response at different cutoff concentrations to the quantitative GC–MS result for THCCOOH. The confirmation cutoff concentration of ≥15 ng/mL for THCCOOH, as utilized in the Substance Abuse and Mental Health Services Administration (SAMHSA) Mandatory Guidelines for Federal Workplace Drug Testing Programs (22), was used to determine if a specimen was positive. True-positive (TP) (immunoassay response ≥ cutoff concentration and GC–MS positive), true-negative (TN) (immunoassay response < cutoff concentration and GC–MS negative), false-positive (FP) (immunoassay response ≥ cutoff concentration and GC–MS negative), and false-negative (FN) (immunoassay response < cutoff concentration and GC–MS positive) were calculated versus GC–MS at the 15 ng/mL cutoff concentration. Diagnostic sensitivity, 100 × [TP/(TP + FN)]; diagnostic specificity, 100 × [TN/(TN + FP)]; and agreement, 100 × [(TP + TN)/(TP + TN + FP + FN)] were calculated at multiple screening cutoff concentrations.

Results

Cannabis use and reported smoke effects

The total, overall amount of cannabis material smoked (determined by weighing cannabis cigarettes provided to all six smokers prior to smoking and weighing remaining cannabis cigarettes and ‘butts' at the end of each 1-h exposure period) by session was as follows: Session 1, total of 10.3 g of 5.3% THC cannabis; Session 2, total of 14.4 g of 11.3% THC cannabis; and Session 3, total of 16.5 g of 11.3% THC cannabis. The mean (range) and median amount of cannabis consumed per smoker was as follows: Session 1, 1.7 g (1.1–2.5 g), 1.6 g; Session 2, 2.4 g (1.6–2.9 g), 2.48 g; and Session 3, 2.8 g (2.1–3.4 g), 2.9 g.

Participants were supplied with goggles to wear during sessions to keep smoke from their eyes and reduce eye irritation. In Session 1, most participants elected not to wear the goggles initially, but then experienced substantial eye irritation. As a result, some smokers reported that they stopped cannabis consumption to avoid adding more smoke to the room at a point where they would have otherwise continued to smoke. Other smokers reported stopping cannabis use during Session 1 because they felt social pressure to do so because others had stopped smoking (due to eye irritation). After Session 1, all participants (both smokers and non-smokers) utilized the goggles part-time or full-time and no longer had issues with eye irritation. The combined effect of these occurrences and possibly other factors was that total cannabis consumption in Session 1, at the lower THC potency, was less than in Sessions 2 and 3.

There was considerable smoke generation in all sessions. Session 2 smoke conditions are illustrated photographically from outside the exposure chamber in Figure 2. The photograph was taken approximately mid-way through the 60 min session. Smoke conditions were visibly less in Session 3, during which the ventilation system was in operation to simulate typical home air-conditioning conditions based on HVAC building standards. All subjects were carefully observed throughout each session and there were no attempts by non-smokers to ‘actively’ inhale sidestream smoke. Overall, observations from outside the smoking chamber were that there was considerable accumulation of smoke during Sessions 1 and 2 (no ventilation), whereas the level of smoke during Session 3 (active ventilation) remained visible but greatly reduced in comparison to previous sessions.
Figure 2.
Photograph from outside the exposure room approximately mid-way through Session 2 in which six cannabis smokers and six non-smokers participated in cannabis smoke studies.
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Photograph from outside the exposure room approximately mid-way through Session 2 in which six cannabis smokers and six non-smokers participated in cannabis smoke studies.

Urinalyses of non-smoker specimens

A complete tabulation of THCCOOH concentrations in urine specimens (determined by GC-MS) is shown in Table I for the 18 non-smokers who participated in Sessions 1, 2 and 3. Average THCCOOH concentrations (n = 6) determined by GC–MS across time for the six non-smokers in each session are shown in Figure 3. All non-smoker urine specimens tested negative for cannabinoids by GC–MS and immunoassay on the morning immediately prior to their participation in the experimental session. Following each session, THCCOOH became detectable for all non-smokers by GC-MS at LOQ (0.75 ng/mL) within 0.25 to 3 h and remained detectable in the last specimen collection pool (30–34 h) for 12 (67%) of the 18 participants. Maximum THCCOOH concentrations (Cmax) appeared in urine within 2–11 h (Tmax) following exposure (Table II). THCCOOH concentrations declined over the 34 h collection period, but frequently remained detectable by GC–MS. The concentrations and times of the last specimens with detectable THCCOOH (Clast, ng/mL and Tlast, hour) are shown in Table II.
Table I

Analyses of non-smokers urine specimens following exposure to concentrated secondhand cannabis smoke

Subject #Time, hTHCCOOH GC/MS, ng/mLVolume, mLCreatinine, mg/dLSpecific gravitypHCRL1 DRI, Cutoff = 20 ng/mL, (Equivalent IA response = 20)Med Tox KIMS 20 Cutoff = 20 ng/mL, (Equivalent IA response = 0)MetroLab EMIT II Plus 20 Cutoff = 20 ng/mL, (Equivalent IA response = 100)One Source CEDIA 20 Cutoff = 20 ng/mL
Session 1
7−10NA56.01.00556.7−2−15110NEG
70.25023064.51.00667.10−14915NEG
713.849187.71.01556.528−36110NEG
727.050177.81.01626.33413158POS
732.619052.61.00566.2−3−13342NEG
741.322024.11.00285.91−13821NEG
74–61.145022.21.00277.0−2−14524NEG
76–82.038050.41.00627.13−11937NEG
78–103.9195106.31.01326.48−9150NEG
710–122.645537.21.00516.80−13924NEG
712–221.944082.51.01146.22−11235NEG
722–261.364050.71.00846.9−2−14723NEG
726–301.7305124.51.01557.1−3−13330NEG
730–341.067040.11.00767.3−3−14615NEG
11−10NA122.01.01536.2−8−1677NEG
110.25012264.91.01096.82−11340NEG
1113.16986.51.01215.528−47102NEG
1121.814053.11.00735.69−9460NEG
1131.317041.21.00485.44−11233NEG
1143.835151.71.01615.725−36100NEG
114–66.871142.11.01735.5276112NEG
116–82.214065.11.00946.17−8450NEG
118–102.114096.11.01396.85−8860NEG
1110–121.821052.31.00705.81−14127NEG
1112–221.573054.41.00737.3−1−14232NEG
1122–261.030086.41.01427.1−4−12636NEG
1126–301.128051.61.00937.3−2−12942NEG
1130–341.3180130.61.01746.2−2−10638NEG
13−10.0NA56.21.01267.1−6−16322NEG
130.250.821819.61.00417.20−14218NEG
1314.019046.81.00947.410−11065NEG
13213.154100.71.01797.4349170POS
13315.63691.11.01547.13635174POS
13414.148100.61.01486.23014139POS
134–69.617090.01.01355.819−6380NEG
136–84.714052.21.00895.87−11351NEG
138–107.0140115.51.01976.011−5668NEG
1310–1219.3210142.21.02345.83383188POS
1312–223.348098.91.01955.7−1−10241NEG
1322–260.951028.71.00766.5−2−15324NEG
1326–302.818087.31.01776.2−2−12730NEG
1330–341.625055.91.01105.4−2−13127NEG
14−10NA28.91.00627.2−3−15723NEG
140.251.19482.61.01447.3−2−13943NEG
1411.415542.01.00777.22−12742NEG
1421.620031.71.00577.12−14032NEG
1432.614048.01.00796.93−10637NEG
14412.245119.11.01616.326−25103NEG
144–65.216098.51.01486.84−8363NEG
146–82.917070.81.01206.51−11035NEG
148–101.520046.41.00797.20−11738NEG
1410–121.722067.21.01097.01−13230NEG
1412–221.983089.11.01286.4−2−13826NEG
1422–26026017.41.00377.0−3−15222NEG
1426–30022075.21.01297.0−3−12531NEG
1430–34014023.51.00606.9−4−14717NEG
15−10NA21.91.00467.3−3−16115NEG
150.25011216.21.00377.2−1−16720NEG
151013610.01.00217.0−1−14717NEG
152014010.41.00206.6−2−13813NEG
1531.010014.51.00296.10−14823NEG
1541.79430.71.00576.3−1−11331NEG
154–61.711035.81.00697.0−1−15538NEG
156–8013012.81.00276.1−2−14719NEG
158–101.013024.91.00577.2−1−14328NEG
1510–121.916544.01.00997.2−1−12246NEG
1512–220.836054.71.00856.0−2−14730NEG
1522–260.828038.11.00826.0−2−15825NEG
1526–30033518.41.00447.0−4−14222NEG
1530–341.342049.41.01046.5−4−13122NEG
16−10NA105.91.01087.4−6−14726NEG
160.251.09857.11.00657.2−1−13438NEG
1616.128225.81.01977.433−51182NEG
1621.112030.01.00337.01−14028NEG
1634.592105.51.01026.413−6989NEG
1641.08921.11.00256.20−14224NEG
164–620.110319.71.00287.038−43103POS
166–82.810577.31.00907.13−12456NEG
168–102.9100141.81.01276.94−10368NEG
1610–122.1130122.21.01126.52−7852NEG
1612–223.5170171.81.01857.23−8665NEG
1622–261.233050.01.00867.5−3−13436NEG
1626–301.8190113.81.01607.4−2−14853NEG
1630–340120249.41.02306.3−1−9159NEG
Session 2
8−1025712.01.00176.01−15717NEG
80.25044015.41.00276.92−16519NEG
815.612542.91.00636.222−8179NEG
82MSMSMSMSMSMSMSMSMS
8310.819039.71.00635.125−4593NEG
843.142010.11.00165.66−14830NEG
84–6MSMSMSMSMSMSMSMSMS
86–86.237532.31.00536.68−11453NEG
88–104.830032.61.00627.27−12748NEG
810–129.518064.71.01277.113−9083NEG
812–226.353080.51.01176.07−10954NEG
822–261.952024.91.00547.32−14932NEG
826–302.644040.51.00677.31−14635NEG
830–344.322086.41.01297.22−12744NEG
23−1040262.51.02635.6−7−12816NEG
230.25061022.41.00296.21−13521NEG
2313.679021.41.00266.38−13934NEG
2326.927017.01.00216.110−10352NEG
23327.316061.61.00795.440−4144POS
23418.834042.41.00545.626−43100NEG
234–657.5100168.71.02125.647108226POS
236–836.890139.11.01985.64448179POS
238–1032.7220162.41.02195.64069196POS
2310–1217.427098.31.01576.022−5098NEG
2312–2225.2510175.61.02265.829−6108POS
2322–265.397036.31.00627.34−13545NEG
2326–3012.4350121.31.01787.16−7190NEG
2330–349.3400112.81.01796.44−8959NEG
37−1013842.31.00665.40−16322NEG
370.25039531.01.00455.53−14735NEG
3714.711034.41.00445.413−9961NEG
37217.060109.31.01385.54547170POS
37323.640161.21.02065.542106218POS
37446.340149.71.02186.946118285POS
374–636.975157.31.02187.14586243POS
376–824.1130110.11.01977.2332170NEG
378–1021.315088.81.01946.827−24123NEG
3710–1219.317085.51.01986.924−33121POS
3712–2220.455099.51.01946.223−48114NEG
3722–2610.436055.11.01287.29−8779NEG
3726–3015.6170108.31.02087.313−74108NEG
3730–3410.3180103.11.02197.14−9173NEG
38−10114102.51.0175.8−5−16614NEG
380.25075011.01.00186.71−16316NEG
3811.911710.81.00166.35−13833NEG
3822.962510.51.00166.45−14538NEG
3837.838023.71.00396.013−10955NEG
38420.112362.71.00975.632−33117POS
384–619.722066.11.01196.126−47105NEG
386–88.347539.21.00736.09−9762NEG
388–108.167043.81.00856.210−11049NEG
3810–124.539027.81.00536.15−14539NEG
3812–224.41,48040.71.00635.86−14122NEG
3822–261.21,86012.71.00245.92−16720NEG
3826–3021,12031.11.00566.90−15327NEG
3830–341.879034.81.0077.2−2−16531NEG
40−1015044.91.00526.6−2−13621NEG
400.25019066.81.00766.71−13230NEG
4011.616296.61.00996.59−10561NEG
4025.560128.81.01556.319−66100NEG
403312258.81.00916.55−10658NEG
4042.816548.51.00836.73−12444NEG
404–6050028.01.00486.91−15036NEG
406–83.171019.51.00346.72−13228NEG
408–101.335033.21.00657.2−1−14340NEG
4010–121.175025.91.00567.2−1−13727NEG
4012–221.575063.61.00947.10−13635NEG
4022–263.648022.81.00496.81−14332NEG
4026–301.440576.91.01187.2−2−13143NEG
4030–34055037.81.00657.2−1−14327NEG
41−1029016.71.00325.8−2−13512NEG
410.25060518.41.00315.60−14418NEG
4115.835022.11.00366.610−10350NEG
41220.424037.01.00787.327−52121NEG
41312.233521.01.00497.111−10075NEG
41429.111552.11.01087.328−27138POS
414–629.721556.51.01087.228−37127NEG
416–81256024.51.00527.28−10367NEG
418–1020.717052.01.01057.419−45126NEG
4110–129.659028.81.00647.27−9860NEG
4112–2211.11,00050.51.00826.58−9967NEG
4122–2601,26056.01.00817.2−2−15024NEG
4126–30935068.51.01147.24−12068NEG
4130–343.792034.11.00707.3−1−16135NEG
Session 3
25−1072109.51.00845.81−15112NEG
250.25019056.71.00645.92−15023NEG
251035018.21.00297.05−14926NEG
2521.821025.41.00397.24−14626NEG
2531.144018.11.00267.14−14818NEG
2541.246018.31.00257.14−14419NEG
254–62.256039.01.00577.33−11924NEG
256–81.161025.31.00377.12−15018NEG
258–100.832027.21.00306.94−14125NEG
2510–122.420088.61.00896.44−13431NEG
2512–2201,95038.51.00416.73−14521NEG
2522–2602,15013.31.00307.23−16415NEG
2526–30088036.41.00547.30−16518NEG
2530–34068043.61.00796.71−14621NEG
26−1030168.71.02286.1−6−14813NEG
260.250150136.71.01966.1−5−15719NEG
2611.750146.01.01996.1−2−14726NEG
2624.640153.61.02096.11−12933NEG
2635.260149.21.02086.22−12541NEG
2646.6100156.71.02136.23−11746NEG
264–68.3130170.41.02206.95−12156NEG
266–88.0200152.21.02227.12−10556NEG
268–108.7270160.11.02277.12−12351NEG
2610–126.8170143.01.02407.00−12650NEG
2612–223.4630109.21.01786.50−14133NEG
2622–262.7170112.91.01597.1−1−13933NEG
2626–302.535096.71.01437.20−12932NEG
2630–342.055088.61.01527.10−14623NEG
27−1036027.11.00576.22−13714NEG
270.25046020.21.00477.33−17819NEG
2712.615048.31.00917.29−12254NEG
2728.211082.01.01417.117−7877NEG
2737.350130.91.01836.115−7379NEG
2741.823024.31.00466.35−14825NEG
274–63.315043.71.00806.94−12835NEG
276–87.095127.61.01937.18−11067NEG
278–105.1290180.11.02305.64−10847NEG
2710–125.190146.51.02346.14−8642NEG
2712–221.471074.01.01285.91−14223NEG
2722–260.848039.61.01007.20−15720NEG
2726–300.854047.21.01007.4−1−15029NEG
2730–34055049.01.00937.21−13224NEG
28−1033028.61.01076.9−1−16116NEG
280.25031532.31.01076.71−14724NEG
2814.36064.71.01625.85−11147NEG
2825.59560.71.01456.17−13243NEG
2833.521023.71.00656.54−14030NEG
2842.227015.31.00436.73−15127NEG
284–69.08087.81.01826.34−10550NEG
286–83.829052.01.01257.02−13834NEG
288–101.333021.81.00546.73−14821NEG
2810–122.617053.91.01186.72−14532NEG
2812–222.5340130.81.01975.8−1−13029NEG
2822–260.973027.71.00847.22−14931NEG
2826–301.046033.31.00877.31−15933NEG
2830–341.045040.31.01057.3−1−15134NEG
29−1017032.91.00316.20−14317NEG
290.25039010.31.00166.82−14833NEG
29103009.71.00187.22−14826NEG
292034020.21.00346.53−12729NEG
2931.317018.91.00417.34−14820NEG
2941.132015.61.00327.33−15724NEG
294–60.857013.11.00257.34−13227NEG
296–8025019.11.00337.22−15423NEG
298–10060020.01.00327.43−13119NEG
2910–12040021.11.00407.43−15830NEG
2912–221.366073.21.00866.91−15127NEG
2922–2601,51012.51.00257.43−15518NEG
2926–30054026.11.00487.33−15324NEG
2930–3401,55013.61.00316.83−15022NEG
36−1040164.01.02336.1−8−13927NEG
360.25038025.31.00456.71−13923NEG
3611.623024.41.00446.94−13021NEG
3622.431022.21.00426.63−14325NEG
3637.18058.91.00926.26−11144NEG
36415.050124.71.01746.914−5994NEG
364–615.5100147.81.02097.414−57107NEG
366–84.823046.51.01027.44−12738NEG
368–103.417039.21.00897.43−14438NEG
3610–123.925055.71.01127.22−12746NEG
3612–227.1380145.41.01986.71−11456NEG
3622–261.585029.31.00777.42−15032NEG
3626–305.3220103.11.01687.41−12061NEG
3630–341.01,01026.71.00587.42−17234NEG
Subject #Time, hTHCCOOH GC/MS, ng/mLVolume, mLCreatinine, mg/dLSpecific gravitypHCRL1 DRI, Cutoff = 20 ng/mL, (Equivalent IA response = 20)Med Tox KIMS 20 Cutoff = 20 ng/mL, (Equivalent IA response = 0)MetroLab EMIT II Plus 20 Cutoff = 20 ng/mL, (Equivalent IA response = 100)One Source CEDIA 20 Cutoff = 20 ng/mL
Session 1
7−10NA56.01.00556.7−2−15110NEG
70.25023064.51.00667.10−14915NEG
713.849187.71.01556.528−36110NEG
727.050177.81.01626.33413158POS
732.619052.61.00566.2−3−13342NEG
741.322024.11.00285.91−13821NEG
74–61.145022.21.00277.0−2−14524NEG
76–82.038050.41.00627.13−11937NEG
78–103.9195106.31.01326.48−9150NEG
710–122.645537.21.00516.80−13924NEG
712–221.944082.51.01146.22−11235NEG
722–261.364050.71.00846.9−2−14723NEG
726–301.7305124.51.01557.1−3−13330NEG
730–341.067040.11.00767.3−3−14615NEG
11−10NA122.01.01536.2−8−1677NEG
110.25012264.91.01096.82−11340NEG
1113.16986.51.01215.528−47102NEG
1121.814053.11.00735.69−9460NEG
1131.317041.21.00485.44−11233NEG
1143.835151.71.01615.725−36100NEG
114–66.871142.11.01735.5276112NEG
116–82.214065.11.00946.17−8450NEG
118–102.114096.11.01396.85−8860NEG
1110–121.821052.31.00705.81−14127NEG
1112–221.573054.41.00737.3−1−14232NEG
1122–261.030086.41.01427.1−4−12636NEG
1126–301.128051.61.00937.3−2−12942NEG
1130–341.3180130.61.01746.2−2−10638NEG
13−10.0NA56.21.01267.1−6−16322NEG
130.250.821819.61.00417.20−14218NEG
1314.019046.81.00947.410−11065NEG
13213.154100.71.01797.4349170POS
13315.63691.11.01547.13635174POS
13414.148100.61.01486.23014139POS
134–69.617090.01.01355.819−6380NEG
136–84.714052.21.00895.87−11351NEG
138–107.0140115.51.01976.011−5668NEG
1310–1219.3210142.21.02345.83383188POS
1312–223.348098.91.01955.7−1−10241NEG
1322–260.951028.71.00766.5−2−15324NEG
1326–302.818087.31.01776.2−2−12730NEG
1330–341.625055.91.01105.4−2−13127NEG
14−10NA28.91.00627.2−3−15723NEG
140.251.19482.61.01447.3−2−13943NEG
1411.415542.01.00777.22−12742NEG
1421.620031.71.00577.12−14032NEG
1432.614048.01.00796.93−10637NEG
14412.245119.11.01616.326−25103NEG
144–65.216098.51.01486.84−8363NEG
146–82.917070.81.01206.51−11035NEG
148–101.520046.41.00797.20−11738NEG
1410–121.722067.21.01097.01−13230NEG
1412–221.983089.11.01286.4−2−13826NEG
1422–26026017.41.00377.0−3−15222NEG
1426–30022075.21.01297.0−3−12531NEG
1430–34014023.51.00606.9−4−14717NEG
15−10NA21.91.00467.3−3−16115NEG
150.25011216.21.00377.2−1−16720NEG
151013610.01.00217.0−1−14717NEG
152014010.41.00206.6−2−13813NEG
1531.010014.51.00296.10−14823NEG
1541.79430.71.00576.3−1−11331NEG
154–61.711035.81.00697.0−1−15538NEG
156–8013012.81.00276.1−2−14719NEG
158–101.013024.91.00577.2−1−14328NEG
1510–121.916544.01.00997.2−1−12246NEG
1512–220.836054.71.00856.0−2−14730NEG
1522–260.828038.11.00826.0−2−15825NEG
1526–30033518.41.00447.0−4−14222NEG
1530–341.342049.41.01046.5−4−13122NEG
16−10NA105.91.01087.4−6−14726NEG
160.251.09857.11.00657.2−1−13438NEG
1616.128225.81.01977.433−51182NEG
1621.112030.01.00337.01−14028NEG
1634.592105.51.01026.413−6989NEG
1641.08921.11.00256.20−14224NEG
164–620.110319.71.00287.038−43103POS
166–82.810577.31.00907.13−12456NEG
168–102.9100141.81.01276.94−10368NEG
1610–122.1130122.21.01126.52−7852NEG
1612–223.5170171.81.01857.23−8665NEG
1622–261.233050.01.00867.5−3−13436NEG
1626–301.8190113.81.01607.4−2−14853NEG
1630–340120249.41.02306.3−1−9159NEG
Session 2
8−1025712.01.00176.01−15717NEG
80.25044015.41.00276.92−16519NEG
815.612542.91.00636.222−8179NEG
82MSMSMSMSMSMSMSMSMS
8310.819039.71.00635.125−4593NEG
843.142010.11.00165.66−14830NEG
84–6MSMSMSMSMSMSMSMSMS
86–86.237532.31.00536.68−11453NEG
88–104.830032.61.00627.27−12748NEG
810–129.518064.71.01277.113−9083NEG
812–226.353080.51.01176.07−10954NEG
822–261.952024.91.00547.32−14932NEG
826–302.644040.51.00677.31−14635NEG
830–344.322086.41.01297.22−12744NEG
23−1040262.51.02635.6−7−12816NEG
230.25061022.41.00296.21−13521NEG
2313.679021.41.00266.38−13934NEG
2326.927017.01.00216.110−10352NEG
23327.316061.61.00795.440−4144POS
23418.834042.41.00545.626−43100NEG
234–657.5100168.71.02125.647108226POS
236–836.890139.11.01985.64448179POS
238–1032.7220162.41.02195.64069196POS
2310–1217.427098.31.01576.022−5098NEG
2312–2225.2510175.61.02265.829−6108POS
2322–265.397036.31.00627.34−13545NEG
2326–3012.4350121.31.01787.16−7190NEG
2330–349.3400112.81.01796.44−8959NEG
37−1013842.31.00665.40−16322NEG
370.25039531.01.00455.53−14735NEG
3714.711034.41.00445.413−9961NEG
37217.060109.31.01385.54547170POS
37323.640161.21.02065.542106218POS
37446.340149.71.02186.946118285POS
374–636.975157.31.02187.14586243POS
376–824.1130110.11.01977.2332170NEG
378–1021.315088.81.01946.827−24123NEG
3710–1219.317085.51.01986.924−33121POS
3712–2220.455099.51.01946.223−48114NEG
3722–2610.436055.11.01287.29−8779NEG
3726–3015.6170108.31.02087.313−74108NEG
3730–3410.3180103.11.02197.14−9173NEG
38−10114102.51.0175.8−5−16614NEG
380.25075011.01.00186.71−16316NEG
3811.911710.81.00166.35−13833NEG
3822.962510.51.00166.45−14538NEG
3837.838023.71.00396.013−10955NEG
38420.112362.71.00975.632−33117POS
384–619.722066.11.01196.126−47105NEG
386–88.347539.21.00736.09−9762NEG
388–108.167043.81.00856.210−11049NEG
3810–124.539027.81.00536.15−14539NEG
3812–224.41,48040.71.00635.86−14122NEG
3822–261.21,86012.71.00245.92−16720NEG
3826–3021,12031.11.00566.90−15327NEG
3830–341.879034.81.0077.2−2−16531NEG
40−1015044.91.00526.6−2−13621NEG
400.25019066.81.00766.71−13230NEG
4011.616296.61.00996.59−10561NEG
4025.560128.81.01556.319−66100NEG
403312258.81.00916.55−10658NEG
4042.816548.51.00836.73−12444NEG
404–6050028.01.00486.91−15036NEG
406–83.171019.51.00346.72−13228NEG
408–101.335033.21.00657.2−1−14340NEG
4010–121.175025.91.00567.2−1−13727NEG
4012–221.575063.61.00947.10−13635NEG
4022–263.648022.81.00496.81−14332NEG
4026–301.440576.91.01187.2−2−13143NEG
4030–34055037.81.00657.2−1−14327NEG
41−1029016.71.00325.8−2−13512NEG
410.25060518.41.00315.60−14418NEG
4115.835022.11.00366.610−10350NEG
41220.424037.01.00787.327−52121NEG
41312.233521.01.00497.111−10075NEG
41429.111552.11.01087.328−27138POS
414–629.721556.51.01087.228−37127NEG
416–81256024.51.00527.28−10367NEG
418–1020.717052.01.01057.419−45126NEG
4110–129.659028.81.00647.27−9860NEG
4112–2211.11,00050.51.00826.58−9967NEG
4122–2601,26056.01.00817.2−2−15024NEG
4126–30935068.51.01147.24−12068NEG
4130–343.792034.11.00707.3−1−16135NEG
Session 3
25−1072109.51.00845.81−15112NEG
250.25019056.71.00645.92−15023NEG
251035018.21.00297.05−14926NEG
2521.821025.41.00397.24−14626NEG
2531.144018.11.00267.14−14818NEG
2541.246018.31.00257.14−14419NEG
254–62.256039.01.00577.33−11924NEG
256–81.161025.31.00377.12−15018NEG
258–100.832027.21.00306.94−14125NEG
2510–122.420088.61.00896.44−13431NEG
2512–2201,95038.51.00416.73−14521NEG
2522–2602,15013.31.00307.23−16415NEG
2526–30088036.41.00547.30−16518NEG
2530–34068043.61.00796.71−14621NEG
26−1030168.71.02286.1−6−14813NEG
260.250150136.71.01966.1−5−15719NEG
2611.750146.01.01996.1−2−14726NEG
2624.640153.61.02096.11−12933NEG
2635.260149.21.02086.22−12541NEG
2646.6100156.71.02136.23−11746NEG
264–68.3130170.41.02206.95−12156NEG
266–88.0200152.21.02227.12−10556NEG
268–108.7270160.11.02277.12−12351NEG
2610–126.8170143.01.02407.00−12650NEG
2612–223.4630109.21.01786.50−14133NEG
2622–262.7170112.91.01597.1−1−13933NEG
2626–302.535096.71.01437.20−12932NEG
2630–342.055088.61.01527.10−14623NEG
27−1036027.11.00576.22−13714NEG
270.25046020.21.00477.33−17819NEG
2712.615048.31.00917.29−12254NEG
2728.211082.01.01417.117−7877NEG
2737.350130.91.01836.115−7379NEG
2741.823024.31.00466.35−14825NEG
274–63.315043.71.00806.94−12835NEG
276–87.095127.61.01937.18−11067NEG
278–105.1290180.11.02305.64−10847NEG
2710–125.190146.51.02346.14−8642NEG
2712–221.471074.01.01285.91−14223NEG
2722–260.848039.61.01007.20−15720NEG
2726–300.854047.21.01007.4−1−15029NEG
2730–34055049.01.00937.21−13224NEG
28−1033028.61.01076.9−1−16116NEG
280.25031532.31.01076.71−14724NEG
2814.36064.71.01625.85−11147NEG
2825.59560.71.01456.17−13243NEG
2833.521023.71.00656.54−14030NEG
2842.227015.31.00436.73−15127NEG
284–69.08087.81.01826.34−10550NEG
286–83.829052.01.01257.02−13834NEG
288–101.333021.81.00546.73−14821NEG
2810–122.617053.91.01186.72−14532NEG
2812–222.5340130.81.01975.8−1−13029NEG
2822–260.973027.71.00847.22−14931NEG
2826–301.046033.31.00877.31−15933NEG
2830–341.045040.31.01057.3−1−15134NEG
29−1017032.91.00316.20−14317NEG
290.25039010.31.00166.82−14833NEG
29103009.71.00187.22−14826NEG
292034020.21.00346.53−12729NEG
2931.317018.91.00417.34−14820NEG
2941.132015.61.00327.33−15724NEG
294–60.857013.11.00257.34−13227NEG
296–8025019.11.00337.22−15423NEG
298–10060020.01.00327.43−13119NEG
2910–12040021.11.00407.43−15830NEG
2912–221.366073.21.00866.91−15127NEG
2922–2601,51012.51.00257.43−15518NEG
2926–30054026.11.00487.33−15324NEG
2930–3401,55013.61.00316.83−15022NEG
36−1040164.01.02336.1−8−13927NEG
360.25038025.31.00456.71−13923NEG
3611.623024.41.00446.94−13021NEG
3622.431022.21.00426.63−14325NEG
3637.18058.91.00926.26−11144NEG
36415.050124.71.01746.914−5994NEG
364–615.5100147.81.02097.414−57107NEG
366–84.823046.51.01027.44−12738NEG
368–103.417039.21.00897.43−14438NEG
3610–123.925055.71.01127.22−12746NEG
3612–227.1380145.41.01986.71−11456NEG
3622–261.585029.31.00777.42−15032NEG
3626–305.3220103.11.01687.41−12061NEG
3630–341.01,01026.71.00587.42−17234NEG

IA, immunoassay; NA, not applicable; MS, missing specimen; NEG, negative; POS, positive.

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Table I

Analyses of non-smokers urine specimens following exposure to concentrated secondhand cannabis smoke

Subject #Time, hTHCCOOH GC/MS, ng/mLVolume, mLCreatinine, mg/dLSpecific gravitypHCRL1 DRI, Cutoff = 20 ng/mL, (Equivalent IA response = 20)Med Tox KIMS 20 Cutoff = 20 ng/mL, (Equivalent IA response = 0)MetroLab EMIT II Plus 20 Cutoff = 20 ng/mL, (Equivalent IA response = 100)One Source CEDIA 20 Cutoff = 20 ng/mL
Session 1
7−10NA56.01.00556.7−2−15110NEG
70.25023064.51.00667.10−14915NEG
713.849187.71.01556.528−36110NEG
727.050177.81.01626.33413158POS
732.619052.61.00566.2−3−13342NEG
741.322024.11.00285.91−13821NEG
74–61.145022.21.00277.0−2−14524NEG
76–82.038050.41.00627.13−11937NEG
78–103.9195106.31.01326.48−9150NEG
710–122.645537.21.00516.80−13924NEG
712–221.944082.51.01146.22−11235NEG
722–261.364050.71.00846.9−2−14723NEG
726–301.7305124.51.01557.1−3−13330NEG
730–341.067040.11.00767.3−3−14615NEG
11−10NA122.01.01536.2−8−1677NEG
110.25012264.91.01096.82−11340NEG
1113.16986.51.01215.528−47102NEG
1121.814053.11.00735.69−9460NEG
1131.317041.21.00485.44−11233NEG
1143.835151.71.01615.725−36100NEG
114–66.871142.11.01735.5276112NEG
116–82.214065.11.00946.17−8450NEG
118–102.114096.11.01396.85−8860NEG
1110–121.821052.31.00705.81−14127NEG
1112–221.573054.41.00737.3−1−14232NEG
1122–261.030086.41.01427.1−4−12636NEG
1126–301.128051.61.00937.3−2−12942NEG
1130–341.3180130.61.01746.2−2−10638NEG
13−10.0NA56.21.01267.1−6−16322NEG
130.250.821819.61.00417.20−14218NEG
1314.019046.81.00947.410−11065NEG
13213.154100.71.01797.4349170POS
13315.63691.11.01547.13635174POS
13414.148100.61.01486.23014139POS
134–69.617090.01.01355.819−6380NEG
136–84.714052.21.00895.87−11351NEG
138–107.0140115.51.01976.011−5668NEG
1310–1219.3210142.21.02345.83383188POS
1312–223.348098.91.01955.7−1−10241NEG
1322–260.951028.71.00766.5−2−15324NEG
1326–302.818087.31.01776.2−2−12730NEG
1330–341.625055.91.01105.4−2−13127NEG
14−10NA28.91.00627.2−3−15723NEG
140.251.19482.61.01447.3−2−13943NEG
1411.415542.01.00777.22−12742NEG
1421.620031.71.00577.12−14032NEG
1432.614048.01.00796.93−10637NEG
14412.245119.11.01616.326−25103NEG
144–65.216098.51.01486.84−8363NEG
146–82.917070.81.01206.51−11035NEG
148–101.520046.41.00797.20−11738NEG
1410–121.722067.21.01097.01−13230NEG
1412–221.983089.11.01286.4−2−13826NEG
1422–26026017.41.00377.0−3−15222NEG
1426–30022075.21.01297.0−3−12531NEG
1430–34014023.51.00606.9−4−14717NEG
15−10NA21.91.00467.3−3−16115NEG
150.25011216.21.00377.2−1−16720NEG
151013610.01.00217.0−1−14717NEG
152014010.41.00206.6−2−13813NEG
1531.010014.51.00296.10−14823NEG
1541.79430.71.00576.3−1−11331NEG
154–61.711035.81.00697.0−1−15538NEG
156–8013012.81.00276.1−2−14719NEG
158–101.013024.91.00577.2−1−14328NEG
1510–121.916544.01.00997.2−1−12246NEG
1512–220.836054.71.00856.0−2−14730NEG
1522–260.828038.11.00826.0−2−15825NEG
1526–30033518.41.00447.0−4−14222NEG
1530–341.342049.41.01046.5−4−13122NEG
16−10NA105.91.01087.4−6−14726NEG
160.251.09857.11.00657.2−1−13438NEG
1616.128225.81.01977.433−51182NEG
1621.112030.01.00337.01−14028NEG
1634.592105.51.01026.413−6989NEG
1641.08921.11.00256.20−14224NEG
164–620.110319.71.00287.038−43103POS
166–82.810577.31.00907.13−12456NEG
168–102.9100141.81.01276.94−10368NEG
1610–122.1130122.21.01126.52−7852NEG
1612–223.5170171.81.01857.23−8665NEG
1622–261.233050.01.00867.5−3−13436NEG
1626–301.8190113.81.01607.4−2−14853NEG
1630–340120249.41.02306.3−1−9159NEG
Session 2
8−1025712.01.00176.01−15717NEG
80.25044015.41.00276.92−16519NEG
815.612542.91.00636.222−8179NEG
82MSMSMSMSMSMSMSMSMS
8310.819039.71.00635.125−4593NEG
843.142010.11.00165.66−14830NEG
84–6MSMSMSMSMSMSMSMSMS
86–86.237532.31.00536.68−11453NEG
88–104.830032.61.00627.27−12748NEG
810–129.518064.71.01277.113−9083NEG
812–226.353080.51.01176.07−10954NEG
822–261.952024.91.00547.32−14932NEG
826–302.644040.51.00677.31−14635NEG
830–344.322086.41.01297.22−12744NEG
23−1040262.51.02635.6−7−12816NEG
230.25061022.41.00296.21−13521NEG
2313.679021.41.00266.38−13934NEG
2326.927017.01.00216.110−10352NEG
23327.316061.61.00795.440−4144POS
23418.834042.41.00545.626−43100NEG
234–657.5100168.71.02125.647108226POS
236–836.890139.11.01985.64448179POS
238–1032.7220162.41.02195.64069196POS
2310–1217.427098.31.01576.022−5098NEG
2312–2225.2510175.61.02265.829−6108POS
2322–265.397036.31.00627.34−13545NEG
2326–3012.4350121.31.01787.16−7190NEG
2330–349.3400112.81.01796.44−8959NEG
37−1013842.31.00665.40−16322NEG
370.25039531.01.00455.53−14735NEG
3714.711034.41.00445.413−9961NEG
37217.060109.31.01385.54547170POS
37323.640161.21.02065.542106218POS
37446.340149.71.02186.946118285POS
374–636.975157.31.02187.14586243POS
376–824.1130110.11.01977.2332170NEG
378–1021.315088.81.01946.827−24123NEG
3710–1219.317085.51.01986.924−33121POS
3712–2220.455099.51.01946.223−48114NEG
3722–2610.436055.11.01287.29−8779NEG
3726–3015.6170108.31.02087.313−74108NEG
3730–3410.3180103.11.02197.14−9173NEG
38−10114102.51.0175.8−5−16614NEG
380.25075011.01.00186.71−16316NEG
3811.911710.81.00166.35−13833NEG
3822.962510.51.00166.45−14538NEG
3837.838023.71.00396.013−10955NEG
38420.112362.71.00975.632−33117POS
384–619.722066.11.01196.126−47105NEG
386–88.347539.21.00736.09−9762NEG
388–108.167043.81.00856.210−11049NEG
3810–124.539027.81.00536.15−14539NEG
3812–224.41,48040.71.00635.86−14122NEG
3822–261.21,86012.71.00245.92−16720NEG
3826–3021,12031.11.00566.90−15327NEG
3830–341.879034.81.0077.2−2−16531NEG
40−1015044.91.00526.6−2−13621NEG
400.25019066.81.00766.71−13230NEG
4011.616296.61.00996.59−10561NEG
4025.560128.81.01556.319−66100NEG
403312258.81.00916.55−10658NEG
4042.816548.51.00836.73−12444NEG
404–6050028.01.00486.91−15036NEG
406–83.171019.51.00346.72−13228NEG
408–101.335033.21.00657.2−1−14340NEG
4010–121.175025.91.00567.2−1−13727NEG
4012–221.575063.61.00947.10−13635NEG
4022–263.648022.81.00496.81−14332NEG
4026–301.440576.91.01187.2−2−13143NEG
4030–34055037.81.00657.2−1−14327NEG
41−1029016.71.00325.8−2−13512NEG
410.25060518.41.00315.60−14418NEG
4115.835022.11.00366.610−10350NEG
41220.424037.01.00787.327−52121NEG
41312.233521.01.00497.111−10075NEG
41429.111552.11.01087.328−27138POS
414–629.721556.51.01087.228−37127NEG
416–81256024.51.00527.28−10367NEG
418–1020.717052.01.01057.419−45126NEG
4110–129.659028.81.00647.27−9860NEG
4112–2211.11,00050.51.00826.58−9967NEG
4122–2601,26056.01.00817.2−2−15024NEG
4126–30935068.51.01147.24−12068NEG
4130–343.792034.11.00707.3−1−16135NEG
Session 3
25−1072109.51.00845.81−15112NEG
250.25019056.71.00645.92−15023NEG
251035018.21.00297.05−14926NEG
2521.821025.41.00397.24−14626NEG
2531.144018.11.00267.14−14818NEG
2541.246018.31.00257.14−14419NEG
254–62.256039.01.00577.33−11924NEG
256–81.161025.31.00377.12−15018NEG
258–100.832027.21.00306.94−14125NEG
2510–122.420088.61.00896.44−13431NEG
2512–2201,95038.51.00416.73−14521NEG
2522–2602,15013.31.00307.23−16415NEG
2526–30088036.41.00547.30−16518NEG
2530–34068043.61.00796.71−14621NEG
26−1030168.71.02286.1−6−14813NEG
260.250150136.71.01966.1−5−15719NEG
2611.750146.01.01996.1−2−14726NEG
2624.640153.61.02096.11−12933NEG
2635.260149.21.02086.22−12541NEG
2646.6100156.71.02136.23−11746NEG
264–68.3130170.41.02206.95−12156NEG
266–88.0200152.21.02227.12−10556NEG
268–108.7270160.11.02277.12−12351NEG
2610–126.8170143.01.02407.00−12650NEG
2612–223.4630109.21.01786.50−14133NEG
2622–262.7170112.91.01597.1−1−13933NEG
2626–302.535096.71.01437.20−12932NEG
2630–342.055088.61.01527.10−14623NEG
27−1036027.11.00576.22−13714NEG
270.25046020.21.00477.33−17819NEG
2712.615048.31.00917.29−12254NEG
2728.211082.01.01417.117−7877NEG
2737.350130.91.01836.115−7379NEG
2741.823024.31.00466.35−14825NEG
274–63.315043.71.00806.94−12835NEG
276–87.095127.61.01937.18−11067NEG
278–105.1290180.11.02305.64−10847NEG
2710–125.190146.51.02346.14−8642NEG
2712–221.471074.01.01285.91−14223NEG
2722–260.848039.61.01007.20−15720NEG
2726–300.854047.21.01007.4−1−15029NEG
2730–34055049.01.00937.21−13224NEG
28−1033028.61.01076.9−1−16116NEG
280.25031532.31.01076.71−14724NEG
2814.36064.71.01625.85−11147NEG
2825.59560.71.01456.17−13243NEG
2833.521023.71.00656.54−14030NEG
2842.227015.31.00436.73−15127NEG
284–69.08087.81.01826.34−10550NEG
286–83.829052.01.01257.02−13834NEG
288–101.333021.81.00546.73−14821NEG
2810–122.617053.91.01186.72−14532NEG
2812–222.5340130.81.01975.8−1−13029NEG
2822–260.973027.71.00847.22−14931NEG
2826–301.046033.31.00877.31−15933NEG
2830–341.045040.31.01057.3−1−15134NEG
29−1017032.91.00316.20−14317NEG
290.25039010.31.00166.82−14833NEG
29103009.71.00187.22−14826NEG
292034020.21.00346.53−12729NEG
2931.317018.91.00417.34−14820NEG
2941.132015.61.00327.33−15724NEG
294–60.857013.11.00257.34−13227NEG
296–8025019.11.00337.22−15423NEG
298–10060020.01.00327.43−13119NEG
2910–12040021.11.00407.43−15830NEG
2912–221.366073.21.00866.91−15127NEG
2922–2601,51012.51.00257.43−15518NEG
2926–30054026.11.00487.33−15324NEG
2930–3401,55013.61.00316.83−15022NEG
36−1040164.01.02336.1−8−13927NEG
360.25038025.31.00456.71−13923NEG
3611.623024.41.00446.94−13021NEG
3622.431022.21.00426.63−14325NEG
3637.18058.91.00926.26−11144NEG
36415.050124.71.01746.914−5994NEG
364–615.5100147.81.02097.414−57107NEG
366–84.823046.51.01027.44−12738NEG
368–103.417039.21.00897.43−14438NEG
3610–123.925055.71.01127.22−12746NEG
3612–227.1380145.41.01986.71−11456NEG
3622–261.585029.31.00777.42−15032NEG
3626–305.3220103.11.01687.41−12061NEG
3630–341.01,01026.71.00587.42−17234NEG
Subject #Time, hTHCCOOH GC/MS, ng/mLVolume, mLCreatinine, mg/dLSpecific gravitypHCRL1 DRI, Cutoff = 20 ng/mL, (Equivalent IA response = 20)Med Tox KIMS 20 Cutoff = 20 ng/mL, (Equivalent IA response = 0)MetroLab EMIT II Plus 20 Cutoff = 20 ng/mL, (Equivalent IA response = 100)One Source CEDIA 20 Cutoff = 20 ng/mL
Session 1
7−10NA56.01.00556.7−2−15110NEG
70.25023064.51.00667.10−14915NEG
713.849187.71.01556.528−36110NEG
727.050177.81.01626.33413158POS
732.619052.61.00566.2−3−13342NEG
741.322024.11.00285.91−13821NEG
74–61.145022.21.00277.0−2−14524NEG
76–82.038050.41.00627.13−11937NEG
78–103.9195106.31.01326.48−9150NEG
710–122.645537.21.00516.80−13924NEG
712–221.944082.51.01146.22−11235NEG
722–261.364050.71.00846.9−2−14723NEG
726–301.7305124.51.01557.1−3−13330NEG
730–341.067040.11.00767.3−3−14615NEG
11−10NA122.01.01536.2−8−1677NEG
110.25012264.91.01096.82−11340NEG
1113.16986.51.01215.528−47102NEG
1121.814053.11.00735.69−9460NEG
1131.317041.21.00485.44−11233NEG
1143.835151.71.01615.725−36100NEG
114–66.871142.11.01735.5276112NEG
116–82.214065.11.00946.17−8450NEG
118–102.114096.11.01396.85−8860NEG
1110–121.821052.31.00705.81−14127NEG
1112–221.573054.41.00737.3−1−14232NEG
1122–261.030086.41.01427.1−4−12636NEG
1126–301.128051.61.00937.3−2−12942NEG
1130–341.3180130.61.01746.2−2−10638NEG
13−10.0NA56.21.01267.1−6−16322NEG
130.250.821819.61.00417.20−14218NEG
1314.019046.81.00947.410−11065NEG
13213.154100.71.01797.4349170POS
13315.63691.11.01547.13635174POS
13414.148100.61.01486.23014139POS
134–69.617090.01.01355.819−6380NEG
136–84.714052.21.00895.87−11351NEG
138–107.0140115.51.01976.011−5668NEG
1310–1219.3210142.21.02345.83383188POS
1312–223.348098.91.01955.7−1−10241NEG
1322–260.951028.71.00766.5−2−15324NEG
1326–302.818087.31.01776.2−2−12730NEG
1330–341.625055.91.01105.4−2−13127NEG
14−10NA28.91.00627.2−3−15723NEG
140.251.19482.61.01447.3−2−13943NEG
1411.415542.01.00777.22−12742NEG
1421.620031.71.00577.12−14032NEG
1432.614048.01.00796.93−10637NEG
14412.245119.11.01616.326−25103NEG
144–65.216098.51.01486.84−8363NEG
146–82.917070.81.01206.51−11035NEG
148–101.520046.41.00797.20−11738NEG
1410–121.722067.21.01097.01−13230NEG
1412–221.983089.11.01286.4−2−13826NEG
1422–26026017.41.00377.0−3−15222NEG
1426–30022075.21.01297.0−3−12531NEG
1430–34014023.51.00606.9−4−14717NEG
15−10NA21.91.00467.3−3−16115NEG
150.25011216.21.00377.2−1−16720NEG
151013610.01.00217.0−1−14717NEG
152014010.41.00206.6−2−13813NEG
1531.010014.51.00296.10−14823NEG
1541.79430.71.00576.3−1−11331NEG
154–61.711035.81.00697.0−1−15538NEG
156–8013012.81.00276.1−2−14719NEG
158–101.013024.91.00577.2−1−14328NEG
1510–121.916544.01.00997.2−1−12246NEG
1512–220.836054.71.00856.0−2−14730NEG
1522–260.828038.11.00826.0−2−15825NEG
1526–30033518.41.00447.0−4−14222NEG
1530–341.342049.41.01046.5−4−13122NEG
16−10NA105.91.01087.4−6−14726NEG
160.251.09857.11.00657.2−1−13438NEG
1616.128225.81.01977.433−51182NEG
1621.112030.01.00337.01−14028NEG
1634.592105.51.01026.413−6989NEG
1641.08921.11.00256.20−14224NEG
164–620.110319.71.00287.038−43103POS
166–82.810577.31.00907.13−12456NEG
168–102.9100141.81.01276.94−10368NEG
1610–122.1130122.21.01126.52−7852NEG
1612–223.5170171.81.01857.23−8665NEG
1622–261.233050.01.00867.5−3−13436NEG
1626–301.8190113.81.01607.4−2−14853NEG
1630–340120249.41.02306.3−1−9159NEG
Session 2
8−1025712.01.00176.01−15717NEG
80.25044015.41.00276.92−16519NEG
815.612542.91.00636.222−8179NEG
82MSMSMSMSMSMSMSMSMS
8310.819039.71.00635.125−4593NEG
843.142010.11.00165.66−14830NEG
84–6MSMSMSMSMSMSMSMSMS
86–86.237532.31.00536.68−11453NEG
88–104.830032.61.00627.27−12748NEG
810–129.518064.71.01277.113−9083NEG
812–226.353080.51.01176.07−10954NEG
822–261.952024.91.00547.32−14932NEG
826–302.644040.51.00677.31−14635NEG
830–344.322086.41.01297.22−12744NEG
23−1040262.51.02635.6−7−12816NEG
230.25061022.41.00296.21−13521NEG
2313.679021.41.00266.38−13934NEG
2326.927017.01.00216.110−10352NEG
23327.316061.61.00795.440−4144POS
23418.834042.41.00545.626−43100NEG
234–657.5100168.71.02125.647108226POS
236–836.890139.11.01985.64448179POS
238–1032.7220162.41.02195.64069196POS
2310–1217.427098.31.01576.022−5098NEG
2312–2225.2510175.61.02265.829−6108POS
2322–265.397036.31.00627.34−13545NEG
2326–3012.4350121.31.01787.16−7190NEG
2330–349.3400112.81.01796.44−8959NEG
37−1013842.31.00665.40−16322NEG
370.25039531.01.00455.53−14735NEG
3714.711034.41.00445.413−9961NEG
37217.060109.31.01385.54547170POS
37323.640161.21.02065.542106218POS
37446.340149.71.02186.946118285POS
374–636.975157.31.02187.14586243POS
376–824.1130110.11.01977.2332170NEG
378–1021.315088.81.01946.827−24123NEG
3710–1219.317085.51.01986.924−33121POS
3712–2220.455099.51.01946.223−48114NEG
3722–2610.436055.11.01287.29−8779NEG
3726–3015.6170108.31.02087.313−74108NEG
3730–3410.3180103.11.02197.14−9173NEG
38−10114102.51.0175.8−5−16614NEG
380.25075011.01.00186.71−16316NEG
3811.911710.81.00166.35−13833NEG
3822.962510.51.00166.45−14538NEG
3837.838023.71.00396.013−10955NEG
38420.112362.71.00975.632−33117POS
384–619.722066.11.01196.126−47105NEG
386–88.347539.21.00736.09−9762NEG
388–108.167043.81.00856.210−11049NEG
3810–124.539027.81.00536.15−14539NEG
3812–224.41,48040.71.00635.86−14122NEG
3822–261.21,86012.71.00245.92−16720NEG
3826–3021,12031.11.00566.90−15327NEG
3830–341.879034.81.0077.2−2−16531NEG
40−1015044.91.00526.6−2−13621NEG
400.25019066.81.00766.71−13230NEG
4011.616296.61.00996.59−10561NEG
4025.560128.81.01556.319−66100NEG
403312258.81.00916.55−10658NEG
4042.816548.51.00836.73−12444NEG
404–6050028.01.00486.91−15036NEG
406–83.171019.51.00346.72−13228NEG
408–101.335033.21.00657.2−1−14340NEG
4010–121.175025.91.00567.2−1−13727NEG
4012–221.575063.61.00947.10−13635NEG
4022–263.648022.81.00496.81−14332NEG
4026–301.440576.91.01187.2−2−13143NEG
4030–34055037.81.00657.2−1−14327NEG
41−1029016.71.00325.8−2−13512NEG
410.25060518.41.00315.60−14418NEG
4115.835022.11.00366.610−10350NEG
41220.424037.01.00787.327−52121NEG
41312.233521.01.00497.111−10075NEG
41429.111552.11.01087.328−27138POS
414–629.721556.51.01087.228−37127NEG
416–81256024.51.00527.28−10367NEG
418–1020.717052.01.01057.419−45126NEG
4110–129.659028.81.00647.27−9860NEG
4112–2211.11,00050.51.00826.58−9967NEG
4122–2601,26056.01.00817.2−2−15024NEG
4126–30935068.51.01147.24−12068NEG
4130–343.792034.11.00707.3−1−16135NEG
Session 3
25−1072109.51.00845.81−15112NEG
250.25019056.71.00645.92−15023NEG
251035018.21.00297.05−14926NEG
2521.821025.41.00397.24−14626NEG
2531.144018.11.00267.14−14818NEG
2541.246018.31.00257.14−14419NEG
254–62.256039.01.00577.33−11924NEG
256–81.161025.31.00377.12−15018NEG
258–100.832027.21.00306.94−14125NEG
2510–122.420088.61.00896.44−13431NEG
2512–2201,95038.51.00416.73−14521NEG
2522–2602,15013.31.00307.23−16415NEG
2526–30088036.41.00547.30−16518NEG
2530–34068043.61.00796.71−14621NEG
26−1030168.71.02286.1−6−14813NEG
260.250150136.71.01966.1−5−15719NEG
2611.750146.01.01996.1−2−14726NEG
2624.640153.61.02096.11−12933NEG
2635.260149.21.02086.22−12541NEG
2646.6100156.71.02136.23−11746NEG
264–68.3130170.41.02206.95−12156NEG
266–88.0200152.21.02227.12−10556NEG
268–108.7270160.11.02277.12−12351NEG
2610–126.8170143.01.02407.00−12650NEG
2612–223.4630109.21.01786.50−14133NEG
2622–262.7170112.91.01597.1−1−13933NEG
2626–302.535096.71.01437.20−12932NEG
2630–342.055088.61.01527.10−14623NEG
27−1036027.11.00576.22−13714NEG
270.25046020.21.00477.33−17819NEG
2712.615048.31.00917.29−12254NEG
2728.211082.01.01417.117−7877NEG
2737.350130.91.01836.115−7379NEG
2741.823024.31.00466.35−14825NEG
274–63.315043.71.00806.94−12835NEG
276–87.095127.61.01937.18−11067NEG
278–105.1290180.11.02305.64−10847NEG
2710–125.190146.51.02346.14−8642NEG
2712–221.471074.01.01285.91−14223NEG
2722–260.848039.61.01007.20−15720NEG
2726–300.854047.21.01007.4−1−15029NEG
2730–34055049.01.00937.21−13224NEG
28−1033028.61.01076.9−1−16116NEG
280.25031532.31.01076.71−14724NEG
2814.36064.71.01625.85−11147NEG
2825.59560.71.01456.17−13243NEG
2833.521023.71.00656.54−14030NEG
2842.227015.31.00436.73−15127NEG
284–69.08087.81.01826.34−10550NEG
286–83.829052.01.01257.02−13834NEG
288–101.333021.81.00546.73−14821NEG
2810–122.617053.91.01186.72−14532NEG
2812–222.5340130.81.01975.8−1−13029NEG
2822–260.973027.71.00847.22−14931NEG
2826–301.046033.31.00877.31−15933NEG
2830–341.045040.31.01057.3−1−15134NEG
29−1017032.91.00316.20−14317NEG
290.25039010.31.00166.82−14833NEG
29103009.71.00187.22−14826NEG
292034020.21.00346.53−12729NEG
2931.317018.91.00417.34−14820NEG
2941.132015.61.00327.33−15724NEG
294–60.857013.11.00257.34−13227NEG
296–8025019.11.00337.22−15423NEG
298–10060020.01.00327.43−13119NEG
2910–12040021.11.00407.43−15830NEG
2912–221.366073.21.00866.91−15127NEG
2922–2601,51012.51.00257.43−15518NEG
2926–30054026.11.00487.33−15324NEG
2930–3401,55013.61.00316.83−15022NEG
36−1040164.01.02336.1−8−13927NEG
360.25038025.31.00456.71−13923NEG
3611.623024.41.00446.94−13021NEG
3622.431022.21.00426.63−14325NEG
3637.18058.91.00926.26−11144NEG
36415.050124.71.01746.914−5994NEG
364–615.5100147.81.02097.414−57107NEG
366–84.823046.51.01027.44−12738NEG
368–103.417039.21.00897.43−14438NEG
3610–123.925055.71.01127.22−12746NEG
3612–227.1380145.41.01986.71−11456NEG
3622–261.585029.31.00777.42−15032NEG
3626–305.3220103.11.01687.41−12061NEG
3630–341.01,01026.71.00587.42−17234NEG

IA, immunoassay; NA, not applicable; MS, missing specimen; NEG, negative; POS, positive.

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Table II

THCCOOH concentrations (maximum and last) and times in non-smoker's urine specimens following secondhand exposure to concentrated cannabis smoke

Session1st Subject2nd Subject3rd Subject4th Subject5th Subject6th SubjectMean/ Median
Cmax, ng/mL
176.819.312.21.920.111.2/9.6
210.857.546.320.15.529.728.3/24.9
32.48.78.291.315.57.5/8.5
Tmax, ha
1251141156.3/5.0
23544243.7/4.0
311925345.7/4.5
Clast, ng/mL
111.31.61.91.31.81.5/1.5
24.39.310.31.81.43.75.1/4
32.420.811.311.4/1.2
Tlast, ha
132323217322828.8/32
232323232283231.3/32
311322832173225.3/30
Session1st Subject2nd Subject3rd Subject4th Subject5th Subject6th SubjectMean/ Median
Cmax, ng/mL
176.819.312.21.920.111.2/9.6
210.857.546.320.15.529.728.3/24.9
32.48.78.291.315.57.5/8.5
Tmax, ha
1251141156.3/5.0
23544243.7/4.0
311925345.7/4.5
Clast, ng/mL
111.31.61.91.31.81.5/1.5
24.39.310.31.81.43.75.1/4
32.420.811.311.4/1.2
Tlast, ha
132323217322828.8/32
232323232283231.3/32
311322832173225.3/30

aTmax for pooled specimens is expressed as the midpoint of the collection period.

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Table II

THCCOOH concentrations (maximum and last) and times in non-smoker's urine specimens following secondhand exposure to concentrated cannabis smoke

Session1st Subject2nd Subject3rd Subject4th Subject5th Subject6th SubjectMean/ Median
Cmax, ng/mL
176.819.312.21.920.111.2/9.6
210.857.546.320.15.529.728.3/24.9
32.48.78.291.315.57.5/8.5
Tmax, ha
1251141156.3/5.0
23544243.7/4.0
311925345.7/4.5
Clast, ng/mL
111.31.61.91.31.81.5/1.5
24.39.310.31.81.43.75.1/4
32.420.811.311.4/1.2
Tlast, ha
132323217322828.8/32
232323232283231.3/32
311322832173225.3/30
Session1st Subject2nd Subject3rd Subject4th Subject5th Subject6th SubjectMean/ Median
Cmax, ng/mL
176.819.312.21.920.111.2/9.6
210.857.546.320.15.529.728.3/24.9
32.48.78.291.315.57.5/8.5
Tmax, ha
1251141156.3/5.0
23544243.7/4.0
311925345.7/4.5
Clast, ng/mL
111.31.61.91.31.81.5/1.5
24.39.310.31.81.43.75.1/4
32.420.811.311.4/1.2
Tlast, ha
132323217322828.8/32
232323232283231.3/32
311322832173225.3/30

aTmax for pooled specimens is expressed as the midpoint of the collection period.

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Figure 3.
Average THCCOOH concentrations in urine specimens collected from six non-smokers exposed to cannabis smoke (note: data are plotted at the mid-point for pooled specimens collected after 4 h).
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Average THCCOOH concentrations in urine specimens collected from six non-smokers exposed to cannabis smoke (note: data are plotted at the mid-point for pooled specimens collected after 4 h).

A total of 27 specimens (3 in Session 1, 22 in Session 2 and 2 in Session 3) had THCCOOH concentrations ≥15 ng/mL (confirmatory test cutoff concentration recommended by SAMHSA) (22). These specimens were produced by two participants (#13, #16) in Session 1, four participants (#23, #37, #38, #41) in Session 2 and one participant (#36) in Session 3.

Accompanying data (volume, creatinine, specific gravity and pH) for each individual specimen or specimen pool are also included in Table I. In addition, immunoassay data are shown for four different screening assays (DRI, KIMS, EMIT II and CEDIA) at a cutoff concentration of 20 ng/mL. Although CRL laboratory conducted equivalent immunoassays (DRI) on Bottles A and B, only the data for Bottle A are shown in Table I. All non-smoker specimens screened negative for cannabinoids at cutoff concentrations of 100 and 75 ng/mL for all screening assays.

Screening assays for cannabinoids at a 50 ng/mL cutoff concentration produced a single presumptive positive result (0.4% positivity rate) by the Lab Corp EMITII 5B3 THC Assay for Subject # 37 (4 h post exposure, Session 2). This result was the only presumptive positive produced by immunoassay from the five laboratories; the remaining four laboratories reported the same specimen as negative. However, all five laboratories reported this specimen as positive at the 20 ng/mL cutoff concentration. The individual who produced the specimen was a 24-year-old female who weighed 98.1 kg and had a body mass index (BMI) of 29.9. As shown in Table I, the specimen contained 46.3 ng/mL of THCCOOH (GC/MS); creatinine was 149.7 mg/dL; and the specific gravity of the specimen was 1.0218.

Multiple presumptive positive results for non-smokers occurred by immunoassay at the 20 ng/mL cutoff concentration across the three exposure sessions as shown in Table I. The number of positives at the 20 ng/mL cutoff concentration in each session by assay (DRI, KIMS, EMIT II, CEDIA) was as follows, respectively: Session 1, 12, 6, 12, 6; Session 2, 22, 8, 22, 12; and Session 3, 0, 0, 1, 0. The first appearance of a presumptive positive (initial test) result at the 20 ng/mL cutoff concentration occurred in specimens collected within 1–4 h following exposure. Following the appearance of the first presumptive positives, individuals continued to test positive for 2–22 h.

Sensitivity and specificity of immunoassays

Immunoassay responses from the 250 non-smoker urine specimens (18 participants, 3 experimental exposure sessions; 14 specimens per subject; two missing specimens) were compared with GC–MS measures of THCCOOH concentration (Table III). Specimens were designated as TP, TN, FP or FN based on whether the specimen contained ≥15 ng/mL of THCCOOH by GC–MS and demonstrated an appropriate response by the immunoassay at the designated cutoff concentration. Overall, more TPs and FPs and fewer FNs were identified at the 20 ng/mL cutoff concentration than at higher concentrations. Sensitivity and agreement also increased, whereas specificity decreased, at the lower cutoff concentration. There were 27 FNs registered by four immunoassays (CEDIA, DRI, KIMS and EMIT II) and 26 FNs by the EMIT II 5B3 assay at the 50 ng/mL cutoff concentration. The mean (range) THCCOOH concentration of the 27 FNs was 24.6 (15.0–57.5) ng/mL. The corresponding mean (range) creatinine for these specimens was 102.6 (19.7–175.6) mg/dL. The major portion (n = 22, 81.5%) of the FNs were from participants in Session 2. Three (11.1%) FNs came from Session 1 and two (7.4%) came from Session 3.

Table III

Comparisons of immunoassay responses to confirmation analyses in non-smoker's urine specimens following secondhand exposure to concentrated cannabis smoke

One Source CEDIA 100 ng/mLOne Source CEDIA 75 ng/mLOne Source CEDIA 50 ng/mLCRL1 DRI 50 ng/mLCRL2 DRI 50 ng/mLMed Tox KIMS 50 ng/mLMetroLab EMIT II Plus 50 ng/mLLab Corp EMIT II 5B3 50 ng/mL
TP00000001
TN223223223223223223223223
FP00000000
FN2727272727272726
Total250250250250250250250250
Sensitivity00000003.7
Specificity100100100100100100100100
Agreement89.289.289.289.289.289.289.289.6
One Source CEDIA 20 ng/mLCRL1 DRI 20 ng/mLCRL2 DRI 20 ng/mLMed Tox KIMS 20 ng/mLMetroLab EMIT II Plus 20 ng/mL
TP1523161025
TN220212214219213
FP3119410
FN12411172
Total250250250250250
Sensitivity55.685.259.337.092.6
Specificity98.795.196.098.295.5
Agreement94.094.092.091.695.2
One Source CEDIA 100 ng/mLOne Source CEDIA 75 ng/mLOne Source CEDIA 50 ng/mLCRL1 DRI 50 ng/mLCRL2 DRI 50 ng/mLMed Tox KIMS 50 ng/mLMetroLab EMIT II Plus 50 ng/mLLab Corp EMIT II 5B3 50 ng/mL
TP00000001
TN223223223223223223223223
FP00000000
FN2727272727272726
Total250250250250250250250250
Sensitivity00000003.7
Specificity100100100100100100100100
Agreement89.289.289.289.289.289.289.289.6
One Source CEDIA 20 ng/mLCRL1 DRI 20 ng/mLCRL2 DRI 20 ng/mLMed Tox KIMS 20 ng/mLMetroLab EMIT II Plus 20 ng/mL
TP1523161025
TN220212214219213
FP3119410
FN12411172
Total250250250250250
Sensitivity55.685.259.337.092.6
Specificity98.795.196.098.295.5
Agreement94.094.092.091.695.2

TP, true positive; TN, true negative; FP, false positive; FN, false negative.

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Table III

Comparisons of immunoassay responses to confirmation analyses in non-smoker's urine specimens following secondhand exposure to concentrated cannabis smoke

One Source CEDIA 100 ng/mLOne Source CEDIA 75 ng/mLOne Source CEDIA 50 ng/mLCRL1 DRI 50 ng/mLCRL2 DRI 50 ng/mLMed Tox KIMS 50 ng/mLMetroLab EMIT II Plus 50 ng/mLLab Corp EMIT II 5B3 50 ng/mL
TP00000001
TN223223223223223223223223
FP00000000
FN2727272727272726
Total250250250250250250250250
Sensitivity00000003.7
Specificity100100100100100100100100
Agreement89.289.289.289.289.289.289.289.6
One Source CEDIA 20 ng/mLCRL1 DRI 20 ng/mLCRL2 DRI 20 ng/mLMed Tox KIMS 20 ng/mLMetroLab EMIT II Plus 20 ng/mL
TP1523161025
TN220212214219213
FP3119410
FN12411172
Total250250250250250
Sensitivity55.685.259.337.092.6
Specificity98.795.196.098.295.5
Agreement94.094.092.091.695.2
One Source CEDIA 100 ng/mLOne Source CEDIA 75 ng/mLOne Source CEDIA 50 ng/mLCRL1 DRI 50 ng/mLCRL2 DRI 50 ng/mLMed Tox KIMS 50 ng/mLMetroLab EMIT II Plus 50 ng/mLLab Corp EMIT II 5B3 50 ng/mL
TP00000001
TN223223223223223223223223
FP00000000
FN2727272727272726
Total250250250250250250250250
Sensitivity00000003.7
Specificity100100100100100100100100
Agreement89.289.289.289.289.289.289.289.6
One Source CEDIA 20 ng/mLCRL1 DRI 20 ng/mLCRL2 DRI 20 ng/mLMed Tox KIMS 20 ng/mLMetroLab EMIT II Plus 20 ng/mL
TP1523161025
TN220212214219213
FP3119410
FN12411172
Total250250250250250
Sensitivity55.685.259.337.092.6
Specificity98.795.196.098.295.5
Agreement94.094.092.091.695.2

TP, true positive; TN, true negative; FP, false positive; FN, false negative.

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The DRI immunoassay was initially performed at 50 and 20 ng/mL cutoff concentrations upon receipt and thawing of the frozen specimens (bottle A). Additional immunoassays were performed subsequently with Bottle B. Results of these immunoassays are shown in Table III. The first and second set of DRI analyses of bottles A and B are designated as ‘CRL1 DRI’ and ‘CRL2 DRI’, respectively. At the 50 ng/mL cutoff concentration, the results of the repeat analyses for bottle B versus bottle A were identical. At the 20 ng/mL cutoff concentration, two FPs and seven TPs for bottle A were converted to two TNs and seven FNs, respectively.

Discussion

Cannabis is widely used as a drug of abuse, but is also used for purported medical benefits by patients with various disease states such as anorexia, nausea, multiple sclerosis and neuropathic pain (23–25). The widespread prevalence and multi-purpose use of high-potency cannabis has led to renewed concerns regarding the effects of secondhand or ‘passive’ smoke exposure. This study was conducted to re-evaluate the risk of non-smokers testing positive for cannabis because of secondhand exposure to cannabis smoke under extreme conditions. The study used higher potency cannabis material, relative to earlier studies, that is more similar to strengths of THC currently encountered in cannabis in the USA. In addition, cannabis-using participants in the present study were allowed to smoke cannabis cigarettes on an ad libitum basis, simulating actual use patterns, rather than being experimentally limited, as was done in a prior study using higher potency cannabis (20). Non-smokers sat in close proximity to smokers for each 1-h exposure session. In the two unventilated sessions, smoke conditions were noticeably high and caused irritation to eyes and mucous membranes when goggles were not used. Overall study conditions were designed to produce a high-intensity, short-term cannabis smoke environment in which subjects would clearly recognize that they were undergoing cannabis smoke exposure.

The current study demonstrated that short-term extreme cannabis smoke exposure produces absorption of sufficient amounts of THC for some non-smokers to test positive in urine assays employing sensitive cutoff criteria for initial and confirmatory testing. These results are not unlike earlier cannabis smoke exposure studies (10–21), but comprehensively demonstrate the important role that initial immunoassay screening tests play in determining a presumptive positive followed by a secondary confirmatory method. Immunoassays employing a cutoff concentration of 50 ng/mL, as recommended by the SAMHSA Mandatory Guidelines for Federal Workplace Drug Testing Programs produced negative test results (99.6% negative) with the single exception for one assay (EMIT II), whereas initial tests with a 20 ng/mL cutoff concentration produced multiple positive results. This is important because some private non-regulated drug testing programs utilize lower initial screening cutoffs (e.g., 20 ng/mL), which our study shows increases the likelihood of a positive test result in non-smokers exposed to secondhand cannabis smoke. It is important to note that THCCOOH was detectable in all subjects in all exposure sessions by GC–MS at the LOQ of the confirmatory assay. A total of 27 (10.8%) of 250 non-smoker's specimens had THCCOOH concentrations ≥15 ng/mL for confirmation analysis; 17 specimens had concentrations in excess of 20 ng/mL. One participant (#16 at 4–6 h) produced a specimen with a concentration of 20.1 ng/mL of THCCOOH in Session 1 and four participants (#'s 23, 37, 38, 41) produced a total of 16 specimens with >20 ng/mL concentrations of THCCOOH in Session 2. These specimens were excreted 2–22 h following exposure. No participants in Session 3 produced specimens >20 ng/mL of THCCOOH demonstrating the important effect that room air ventilation had upon lowering exposure and intake of THC by non-smokers.

There was considerable variation in the response across the different immunoassay tests to specimens containing ≥15 ng/mL of THCCOOH. The KIMS 20 assay produced the lowest number of TPs (n = 10) and EMIT II produced the highest number (n = 25). Following cannabis exposure, THCCOOH is excreted in urine primarily as a glucuronide conjugate along with small amounts of free metabolite (26, 27). The differences in immunoassay response to specimens containing ≥15 ng/mL of THCCOOH was likely due to differences in cross-reactivity with the glucuronide conjugate of THCCOOH. Package insert information regarding immunoassay cross-reactivity with the glucuronide conjugate at a 20 ng/mL cutoff concentration appear to be only reported for EMIT II (79%) and KIMS (44.1%).

Study limitations

Limitations of the present study include the fixed order of conditions, non-blindness to the ventilation conditions, the single session and small number of participants in each study condition and the possibility of within-session social influences among the smokers. The extent of passive cannabis smoke exposure and absorption is known to vary according to a number of factors including THC potency, amount of cannabis smoked, duration of exposure and environmental factors such as enclosure space, ventilation conditions and proximity of non-smokers to smokers. Additional considerations include assay sensitivity and specificity and administratively designated cutoff concentrations that determine whether a test is reported as positive or negative.

In the present study, non-smokers were seated alongside smokers in very close proximity. Distance of non-smokers from smokers is likely to be an important factor in determining the extent of absorption of aerosolized THC. Also, the study only evaluated the effects of an acute 1-h exposure period to high-intensity smoke conditions. Hence, the conditions of this study were designed to simulate short-term extreme exposure to cannabis smoke. Multiple exposures to cannabis smoke over longer periods and varying intensities could conceivably result in some accumulation of THC and produce different results. However, an earlier study of smoke exposure from lower potency cannabis (2.8% THC) in which subjects were exposed over six consecutive days for 1 h each day produced only suggestive evidence of accumulation or enhancement of positivity rates (12).

The current study employed chronic, daily cannabis smokers to create extreme smoke exposure conditions in the study chamber. Occasional cannabis smokers may produce greater amounts of side stream smoke as a result of fewer inhalation attempts, but it is presumed that they would combust less cannabis overall in a typical smoking session. Other methods of cannabis inhalation, e.g., ‘vaping’ devices that deliver aerosolized oil derived from cannabis, may also alter levels of exposure to non-smokers. Consequently, the current results should be interpreted as being most representative of short-term exposure to extreme, high-intensity cannabis smoke and can only be partially extrapolated to the multiple scenarios of exposure that may occur for non-smokers in other situational and environmental conditions (e.g., ventilation conditions, amount and frequency of exposure).

Conclusions

Cannabis potency and room ventilation were demonstrated to be two major factors in determining the extent of cannabis smoke exposure to non-smokers residing in close proximity to smokers. Short-term exposure to high-intensity smoke from combusted cannabis resulted in non-smoker inhalation of sufficient amounts of THC to produce positive presumptive urine tests by immunoassay with a 20 ng/mL cutoff concentration, but only a single positive occurred at higher cutoff concentrations (50 ng/mL). GC–MS analysis of presumptive positives confirmed the presence of THCCOOH at ≥15 ng/mL in some specimens. Whether test results for non-smokers would be reported as positive or negative will be highly dependent upon the sensitivity of initial and confirmatory tests and related reporting criteria. Overall, these results indicated that extreme smoke exposure can produce positive tests at lower cutoff concentrations, but not generally at the higher initial test cutoff concentration in general use by SAMHSA's Mandatory Guidelines for Federal Workplace Drug Testing Programs.

Acknowledgments

E.J.C. is a consultant to the Division of Workplace Programs, Substance Abuse and Mental Health Services Administration (SAMHSA) and has an Adjunct Professor appointment with Johns Hopkins University School of Medicine, Baltimore, MD, USA. R.V., G.E.B. and E.S.H. are with Johns Hopkins School of Medicine, Baltimore, MD, USA. J.M.M. is an employee of RTI International and C.L. and R.F. are employees of SAMHSA.

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