Comparison of Urine 4-(Methylnitrosamino)-1-(3)Pyridyl-1-Butanol and Cotinine for Assessment of Active and Passive Smoke Exposure in Urban Adolescents

Abstract

Many adolescents are exposed to tobacco smoke, from either active smoking (CS) or secondhand smoke (SHS) exposure. Tobacco-specific biomarkers of exposure include cotinine (detects use in past 2-4 days) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL; detects use for a month or longer). NNAL is expected to detect more intermittent tobacco exposure. We compared NNAL and cotinine as biomarkers of exposure to tobacco in urban adolescents and determined the optimal NNAL cutoff point to distinguish CS from SHS exposure. Surplus urine samples, collected from 466 adolescents attending pediatric well or urgent care visits at Zuckerberg San Francisco General Hospital in 2013 to 2014, were assayed for cotinine and NNAL. Ninety-four percent of adolescents had measurable levels of NNAL compared with 87% for cotinine. The optimal NNAL cutoff point to distinguish CS from SHS was 9.6 pg/mL by latent class or 14.4 pg/mL by receiver-operating characteristic analysis. Cotinine and NNAL were strongly correlated, but the correlation slopes differed for active versus SHS-exposed adolescents. Among nonsmokers, NNAL levels were significantly higher in African American (median, 3.3 pg/mL) compared with other groups (0.9-1.9 pg/mL), suggesting greater exposure to SHS. Urine NNAL screening finds a large majority (94%) of urban adolescents are exposed to tobacco. African Americans are exposed to higher levels of SHS than other ethnic/racial groups. SHS is associated with significant medical morbidity in adolescents. Routine biochemical screening with NNAL or cotinine detects high prevalence of SHS exposure and should be considered as a tool to reduce SHS exposure in high-risk populations. .

High exposure to nicotine among adolescents who use Juul and other vape pod systems (‘pods’)

“…The median urinary cotinine concentration measured in our participants who used pods was 244.8 ng/mL (IQR 8.4–1255.8), higher than 155.2 ng/mL (IQR: 68.8–579.2) reported by Benowitz et al in 55 adolescents (ages 13–19 years) who regularly smoked conventional tobacco cigarettes 6. All analysed samples had either undetectable or very low levels of the urinary tobacco-specific biomarker, NNAL, confirming lack of exposure to tobacco smoke.…”

Cell-specific toxicity of short-term JUUL aerosol exposure to human bronchial epithelial cells and murine macrophages exposed at the air–liquid interface

“…Physiological evidence of high absorption of nicotine salt from JUUL pods was observed in a clinical study by Goniewicz and colleagues [78], who tested urinary cotinine levels, a biomarker of nicotine exposure, in 12-21 year olds who use podstyle devices on a regular basis. The study found that participants who used nicotine salt-containing devices had average urinary cotinine levels of 244.8 ng/mL, which is higher than a previous report of cotinine levels from 13 to 19 year olds (66-132 ng/mL), who regularly smoked tobacco cigarettes [79]. In our study, we found that JUUL crème brûlée aerosol contained low levels of carbonyls, including formaldehyde (0.053 µg/puff, Table 1), which is lower than levels previously reported for JUUL aerosols (0.07-0.50 µg/puff ) [73,76].…”

Measuring e-cigarette addiction among adolescents

“…NNAL has a half-life of 10–18 days and remains detectable for 6–12 weeks after combustible tobacco exposure 24. NNAL concentrations were normalised for creatinine25 and should not be present in levels above 10 pg/mg creatinine in adolescents with no recent active smoking and either past smoking or light secondhand smoke exposure (neither of which would be expected to significantly affect cotinine) 26. Saliva and urine samples were analysed at the Clinical Pharmacology Laboratory at the University of California, San Francisco.…”

“…Analyses were conducted in both the full sample (N=173) and in the subsample of e-cigarette only users (N=144). As described above, e-cigarette only users were defined as adolescents who reported no combustible cigarette use in the past 24 hours and had NNAL levels<10 pg/mL creatinine 26. Due to rapid changes in e-cigarette product availability and regulation, partial correlations were also examined, adjusting for date of assessment (ie, days passed from assessment date to present date).…”