1. Researchers conducted chamber studies to measure the particles produced from e-cigarettes. They found that e-cigarette particles were smaller in size and lower in mass concentration compared to traditional cigarettes. 2. While e-cigarette particle mass concentrations were much lower than cigarettes and urban environments, the number of particles could approach or exceed urban levels if multiple users vaped in an enclosed space. 3. More research is still needed, but preliminary results suggest passive vaping may pose an exposure risk without ventilation. Overall health risks are likely smaller than from traditional cigarettes but warrant further study of nanoparticle exposures.

1. A chamber study of second-hand E-cigarette “smoke” – a methodology and some preliminary results
Gordon McFiggans1 & Roy Harrison2
Rami Alfarra1, James Allan1, Jamie Whitehead1
David Beddows2
1. University of Manchester
2. University of Birmingham
g.mcfiggans@manchester.ac.uk; r.m.harrison@bham.ac.uk
PM is the most important contributor to Air Quality
COMEAP, 20101 estimated 340,000 years of total survival time was lost to the current population across the UK in 2008
Speculated that 200,000 annual premature deaths attributable to air pollution higher than the 116,000 attributed to the combined effects of alcoholism, obesity and smoking.
estimated cost of PM in the UK of €15K - €40K / emitted tonne in terms of mortality2
1. COMEAP, 2010, ISBN 978-0-85951-685-3
2. Revealing the costs of air pollution from industrial facilities in Europe, ISSN 1725-2237

2. Several different major atmospheric particle types
Primary mechanical
(“dust”, pollen etc.)
Primary combustion
(“smoke”, “soot” etc.)
Secondary (natural e.g. “smokey mountains” or manmade “smog”)
Volatile primary / secondary
(clouds, spray perfumes, air fresheners etc…)

3. 3m x 3m x 2m FEP Teflon bag Simulated solar spectrum, filtering to get rid of excess UV Ultraclean dilution air (pptv level of gaseous contaminants and < 0.1 μg m-3 particles)
Photochemical chamber experiments
Inject individual chemicals as particle precursors
…or real emission sources at real atmospheric concentrations e.g. continuous emission from tree saplings
…or exhaust sampled from diesel engine
sample with sensitive research-grade online atmospheric instruments

4. 10 x 5 second puffs diluted into 18 m-3 ultraclean air Measure: particle size particle number particle composition their changes with time
…or active / passive e-cigarette or real cigarettes emissions

5. 10 Puffs of E-Cigarette diluted into 18 m3 air, in the dark
1st Mode
2nd Mode
(near identical)
1st 2nd Mode
(smaller)
Quite high numbers, small particles (40-70 nm), low mass concentration, simple composition that doesn’t change much, evaporating and depositing with time

6. 1st Mode
2nd Mode
Light only
Light & Ozone
Ozone injected
Quite high numbers of small particles (40-60 nm), low mass concentration, simple composition that oxidises moderately, low evaporation plus deposition
1st Mode
2nd Mode
10 Puffs of E-Cigarette diluted into 18 m3 air, light + O3

7. SP-AMS
(composition of soot containing particles)
AMS
(composition of all particles)
Moderately high numbers of larger (400 nm) sooty particles, much higher mass concentration, complex composition (paraffinic, olefinic and aromatic) that oxidises moderately, deposited but no evidence of evaporation
7 Puffs of Traditional Cigarette diluted in 18 m3 air, light + O3

8. Diesel Engine: 2000RPM, 40% load, Dilution 275:1 “roadside”, with catalytic converter
SP-AMS
(composition of soot containing particles)
AMS
(composition of all particles)
High numbers of quite small (100 nm) sooty particles, moderate mass concentration, complex composition (paraffinic and olefinic), deposited but no evidence of evaporation

9. Secondary Organic Aerosol from 250 ppb Limonene (levels reported in indoor environments)
Quite high numbers of large secondary particles (300 nm), high mass concentration, moderately complex composition quite highly oxidised, deposited but no evidence of evaporation

10. We can measure the size, number, composition, properties and atmospheric changes to particles made from e-cigarettes E-cigarettes produce fine particles that can persist but evaporate and deposit with time The particles are simple in composition that changes little with time in the atmosphere In comparison, traditional cigarette smoke is involatile, comprising larger sooty particles with a complex organic matrix E-cigarette particles are produced at low mass loading compared to recognised sources of particle pollution such as diesel exhaust Particle emissions from e-cigarettes should also be set in context of those made in the indoor atmosphere from some household products such as cleaning materials We have the capability to cover a much wider range of measurements of all properties of interest. These are illustrative first findings.
Summary

11. 1. Particle mass concentration
 Size of chamber, versus size of small room:
18 m3 versus 30 m3
 Mass concentrations of particulate matter in chamber are
stable initially at about 4 μg m-3 from 10 puffs if all smoke
were exhaled; likely to be much lower under “normal” usage
 Implies a concentration increase in the chamber of around
0.4 μg m-3 per puff, or around 0.2 μg m-3 per puff in a small
room
 If 5 vapers each generate 5 puffs per minute for 10 minutes,
the implied concentration is 50 μg m-3
 Compares with an urban PM2.5 concentration in UK cities of
ca. 15 μg m-3, and a WHO guideline for PM2.5 of 25 μg m-3
(24-hour average) or 10 μg m-3 (annual mean)
What do the chamber data imply for public health?

12. 2. Particle number concentration
 Particle number is a measure of the nanoparticles present.
There is some evidence that these are more toxic per unit mass
than larger particles
 The most recent epidemiology from London (Atkinson et al.,
2010) showed a statistically significant association between
particle number concentration and cardiovascular mortality
 Initial particle count in the chamber was 20 x 103 particles/cc,
from equivalent to 10 puffs directly exhaled; likely to be much
lower under “normal” usage
 Implies a concentration increase in the chamber of around 2 x
103 particles/cc per puff, or around 1 x 103 per puff in a small
room
 If 5 vapers each generate 5 puffs per minute for 10 minutes, the
implied concentration is 250 x 103 particles per cc
 Compares with a typical urban concentration of around 10 x 103
particles per cc, and exceeds concentrations measured
alongside busy roads
What do the chamber data imply for public health?

13. CONCLUSIONS
 The data are preliminary and need to be repeated and
extended
 The preliminary data provide evidence for a possible
exposure risk to passive smokers in enclosed spaces with
no ventilation if all the emissions from e-cigarettes were
exhaled
 Particle mass concentrations are about 100-fold lower than
from conventional cigarettes, but particle number
concentrations are similar if directly exhaled
 Health risks are likely to be smaller than those associated
with conventional cigarettes
 Further measurements, especially for nanoparticle number
concentrations, are strongly recommended
What do the chamber data imply for public health?