The effects of electronic cigarette emissions on systemic cotinine levels, weight and postnatal lung growth in neonatal mice.

Sharon A Mcgrath-Morrow,Angela Aherrera,Jonathan P Winickoff,Gang Chen,Alla Malinina,Enid Neptune,Joseph M Collaco,Patrick Breysse,Madoka Hayashi,Philip Lazarus,Jonathan D Klein,Armando Lopez

doi:10.1371/journal.pone.0118344

Abstract

Background/ObjectiveElectronic cigarette (E-cigarettes) emissions present a potentially new hazard to neonates through inhalation, dermal and oral contact. Exposure to nicotine containing E-cigarettes may cause significant systemic absorption in neonates due to the potential for multi-route exposure. Systemic absorption of nicotine and constituents of E-cigarette emissions may adversely impact weight and lung development in the neonate. To address these questions we exposed neonatal mice to E-cigarette emissions and measured systemic cotinine levels and alveolar lung growth.Methods/Main ResultsNeonatal mice were exposed to E-cigarettes for the first 10 days of life. E-cigarette cartridges contained either 1.8% nicotine in propylene glycol (PG) or PG vehicle alone. Daily weights, plasma and urine cotinine levels and lung growth using the alveolar mean linear intercept (MLI) method were measured at 10 days of life and compared to room air controls. Mice exposed to 1.8% nicotine/PG had a 13.3% decrease in total body weight compared to room air controls. Plasma cotinine levels were found to be elevated in neonatal mice exposed to 1.8% nicotine/PG E-cigarettes (mean 62.34± 3.3 ng/ml). After adjusting for sex and weight, the nicotine exposed mice were found to have modestly impaired lung growth by MLI compared to room air control mice (p<.054 trial 1; p<.006 trial 2). These studies indicate that exposure to E-cigarette emissions during the neonatal period can adversely impact weight gain. In addition exposure to nicotine containing E-cigarettes can cause detectable levels of systemic cotinine, diminished alveolar cell proliferation and a modest impairment in postnatal lung growth.

Highlights

E-cigarettes known as electronic nicotine delivery systems (ENDS) have become increasingly popular among current tobacco smokers and people who have never smoked.[1;2] a paucity of data exists on the in vivo distribution and systemic effects of nicotine solutions delivered by E-cigarette devices, or their potential for exposure in the nonuser. [3] Adverse consequences from E-cigarette exposure may be most pronounced in the very young
Mice that were exposed to 0% nicotine/propylene glycol (PG) weighed significantly less than mice exposed to room air after similar regression analysis (Trial 1: p = 0.001, Trial 2: p = 0.008) with an 11.5% decrease in total body weight compared to age-matched room air mice
In this study we demonstrated that neonatal mice exposed to 1.8% nicotine/PG containing Ecigarette emissions for one or two times a day had elevated plasma and urine cotinine levels and impaired alveolar growth at ten days of age

Summary

Introduction

E-cigarettes known as electronic nicotine delivery systems (ENDS) have become increasingly popular among current tobacco smokers and people who have never smoked.[1;2] a paucity of data exists on the in vivo distribution and systemic effects of nicotine solutions delivered by E-cigarette devices, or their potential for exposure in the nonuser. [3] Adverse consequences from E-cigarette exposure may be most pronounced in the very young. [3] Adverse consequences from E-cigarette exposure may be most pronounced in the very young. In addition to inhalation of expired constituents (nicotine, flavorings and carrier liquid), small children may be exposed to E-cigarette toxins through breastmilk and contact with contaminated surfaces. Secondhand and thirdhand exposure to E-cigarette emissions may be higher in young children who spend extended indoor time with a caregiver who is an E-cigarette user. Constituents exhaled from an E-cigarette user has been shown to contain indoor air nicotine levels similar to those of a vapor-generated smoking machine.[4] detectable levels of cotinine have been reported in subjects passively exposed to E-cigarettes with levels similar to those passively exposed to tobacco smoke. Detectable levels of cotinine have been reported in subjects passively exposed to E-cigarettes with levels similar to those passively exposed to tobacco smoke. [5]

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