gordon mcfiggans and roy harrison - e-cigarette summit 2014
TRANSCRIPT
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
[email protected]; [email protected]
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
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…)
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
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
10 Puffs of E-Cigarette diluted into 18 m3 air, in the dark
1st Mode
2nd Mode
(near identical)
1st Mode 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
1st Mode
2nd Mode
Light only
Light & Ozone
Ozo
ne
in
jecte
d
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
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
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
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
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
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?
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?
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?