Aerosol Characterisation of e-cigarettes. Ross Cabot, Anna Koc, Caner U. Yurteri & John McAughey

Transcription

1 Aerosol Characterisation of e-cigarettes Ross Cabot, Anna Koc, Caner U. Yurteri & John McAughey European Aerosol Conference, Prague 2-6 September

2 Organisation Background Description History Regulation Particle size and concentration measurement Results Comparison with tobacco smoke Estimates of deposition behaviour Summary 2

3 Background

4 Background : e-cigarettes Typically cigarette shaped devices Battery powered heating element vaporising liquid mixture of glycerol, propylene glycol, water and nicotine (+ menthol, flavours in some cases) No combustion Cooling and super-saturation such that condensation aerosol formed Can be disposable / refillable / rechargeable LED (power indicator) Microprocessor (controls heating element and LED) Battery Pressure Sensor Heating Element Formulation Reservoir Mouthpiece 4

5 Background : e-cigarettes Significant growth of market from 2004 to date Originated in China (Ruyan) Analyst estimates of $1-2 billion sales in 2013 Diverse regulatory landscape de facto bans (e.g. Australia - nicotine free) Regulated as tobacco product (e.g. South Korea, USA) Regulated as licenced medical product (e.g. Canada, Japan, some EU) Regulated as consumer product (e.g. UK, France, Germany, Italy, Russia, Issues Spain - if no therapeutic claims) Ingredients (including purity) Consistency of output Therapeutic Use (e.g. cessation) versus Harm Reduction Indoor Use 5

6 Risk & Harm Reduction The harm associated with cigarette smoking is almost entirely caused by the toxins and carcinogens found in tobacco smoke not the nicotine (Royal College of Physicians 2007). Nicotine is the main addictive chemical that makes it difficult to quit smoking. McNeill and Munafὸ (2012) J Psychopharmacology 37 (1)

7 Consistency of Output Range mg nicotine/puff (vs ~0.010mg/puff for 1mg ISO NFDPM cigarette) Goniewicz M. et al (2013) Nic & Tob Res, 15,

8 Aerosol Measurement

9 Aerosol Measurement Light scattering Spraytec (Malvern, UK) Electrical mobility DMS500 and SCS (Cambustion, UK) Puffing regimes 3s duration square or sine wave 50, 55 and 80 ml volumes No secondary dilution Cigarette smoke measurements also by electrical mobility, typically for 2s puffs of 35 or 55 ml 9

10 Mass Output Versus Puff Duration Output delay (Ingebrethsen, 2012) Combination of sinusoidal profile + breath actuated pressure sensor + heating lag Delay reduced with square wave puff profiles (this work) Output varied with puff duration and battery power (Ingebrethsen, 2012) Ingebrethsen et al, Inhalation Toxicology, 2012; 24(14):

11 Results

12 e-cigarette A : UK Rechargeable EM n=432 LS n=12 CMD (nm) 63 ± 9 VMD (nm) 252 ± ± 39 EM : electrical mobility LS : Light scattering Particle Number per puff 4.99e10 ± 2.26e9 Gravimetric mass per puff was 1.86 ± 0.13 mg per puff GSD = Aerosol composition source Density = 1216 kg.m -3 Volumetric diameter of average mass of 388 nm Evaporation losses - mobility Reduced loss at lower dilution ratio Mobility measure currently better for reproducibility data (better smoking engine)

13 Puff by Puff Particle Diameter 3R4F reference 55 / 2 / 30 : 12 puffs e-cigarette 50 / 3 / 30 : Puffs Cambustion DMS500 and SCS 1 Cumulative Frequency R4F cigarette : Decreasing diameter with increasing puff number (reduced coagulation time in shortening tobacco rod) e-cigarette A VMD (nm) Note : set of 12 e-cigarette puffs for illustration : RSD = 4.4% over 432 puffs

14 Puff by Puff Particle Number 3R4F reference 55 / 2 / 30 : 12 puffs (n=5 : 30x 2y dilution) e-cigarette 50 / 3 / 30 : Puffs in groups of 12 Cambustion DMS500 and SCS 2.50E E E E+11 e-cigarette A 3R4F cigarette : Increasing particle number with puff (reduced coagulation time + more tobacco mass burnt) 5.00E E e-puff 1 e-puff 2 e-puff 3 e-puff 4 e-puff 5 e-puff 6 e-puff 7 e-puff 8 e-puff 9 e-puff 10 e-puff 11 e-puff 12 Puff 1 Puff 2 Puff 3 Puff 4 Puff 5 Puff 6 Puff 7 Puff 8 Puff 9 Puff 10 Puff 11 Puff 12 Particle Number

15 Device Tech CMD (nm) VMD (nm) P # per puff Mass (mg) per puff Cigarette EM e10 2e Notes Adam et al, 2009 Anal BioanalChem394: 1193 Mouth-aged EM Ingebrethsen et al, 2011 AS&T 45:1422 Ruyan EM 20 60, (600) - - TSI EEPS :Laugesen, SRNT2009, Dublin, Poster 5-11 Bloog MaxX EM 117 (PG) Common bimodal, GSDs v Cig cmd: Fusion SMPS 180 (Gly) nm, vmd250 nm : Zhang, 2013 NicTobRes 15:501 B EM e11 ±7.6e ± :12y dilution : 55 ml 3s sine wave B Opt 265 ± e11 ± 1.5e11 - Multi-λ extinction : Ingebrethsen et al, 2012 Inh Tox 24:976 C EM e11 ±5.7e ± :1 2y dilution : 55 ml 3s sine wave C Opt 339 ± e11 ± 2.8e10 - Multi-λ extinction : Ingebrethsen et al, 2012 Inh Tox 24:976 A EM 63 ±9 252 ±11 5.0e10 ±2.3e9 1.9 ±0.1 UK Recharg, 50 ml sine wave,n=432 A Opt 435 ± UK Recharg, 50 ml sine wave, n=12 B EM 41±3 2.7e9 ±9.1e8 - US Dispos, 55 ml sine wave, n=60 B Opt 389± US Dispos, 55 ml sine wave, n=60 C EM 208±32 3.0e10 ±1.3e10 - US Recharg, PG, 55 ml sine wave, n=60 C Opt 433± US Recharg,PG, 55 ml sine wave, n=60 D EM 24 ± ±7 6.7e10 ±7.5e9 1.7 ±0.17 UK Dispos, 80 ml squarewave, n = 135 D Opt 463 ± UK Dispos, 80 ml squarewave, n = 135 E EM 12 ±1 235 ±7 8.8e10 ±4.5e9 US Dispos, 80 ml squarewave, n = 40 E Opt 388 ± US Dispos, 80 ml squarewave, n = 40

16 Discussion

17 Predicted Deposition Smoker behaviour with deeper breaths than tidal breathing, and a pause increase lung deposition of cigarette smoke to the 50 80% range 1, more than predicted for nm diameter aerosols 2 Lung deposition of glycerol from e-cigarettes has not been measured directly. Limited measures (n=2) for glycerol within tobacco smoke report 50% 3 & 87% 4 Exhaled composition of the aerosols is very different The cigarette smoke has an organic core, which is relatively water insoluble The e-cigarette aerosol will contain residual glycerol with a high percentage of accreted water (hygroscopicity) The high water content is expected to disperse rapidly in air on exhalation, as is observed. Respiratory deposition model (ICRP 66) with deposition Minimum in nm ( µm) region. Smoke deposition efficiency is higher through deeper inhalation and pause 1. Baker & Dixon (2006) Inhalation Toxicology. 18 (4): International Commission for Radiological Protection ICRP Publication 66 : (1994) Ann. ICRP 24 (1-3). 3. Moldoveanu & St Charles (2007) : Beiträge zur Tabakforschung 22(4) : Ingebrethsen (1989)in: Extrapolation of dosimetric relationships for inhaled particles and gases, (ed JD Crapo et al), Academic Press, pp

18 e-cigarette aerosol - Summary Latest generation e-cigarettes reproducible for particle number & particle size output (± 5%) Electrical mobility data reflects this precision Electrical mobility data under-predicts size Worse at higher dilution ratios implying evaporation Optical size data similar over range of products Optical concentration data agrees with gravimetric data Size and concentration data similar to cigarette smoke Consistent with formation of condensation aerosol Chemical composition very different in absence of combustion 18

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