Content uploaded by Simon Chapman
Author content
All content in this area was uploaded by Simon Chapman on Jul 23, 2019
Content may be subject to copyright.
Secondhand smoke exposure levels in outdoor
hospitality venues: a qualitative and quantitative
review of the research literature
Andrea S Licht,
1,2
Andrew Hyland,
2
Mark J Travers,
2
Simon Chapman
3
▸Additional data are
published online only. To view
these files please visit the
journal online (http://dx.doi.
org/10.1136/tobaccocontrol-
2012-050493).
1
Department of Social and
Preventive Medicine, State
University of New York at
Buffalo, Buffalo, New York,
USA
2
Department of Health
Behavior, Roswell Park Cancer
Institute, Buffalo, New York,
USA
3
School of Public Health,
University of Sydney, Sydney,
Australia
Correspondence to
Andrea Licht, Department
of Health Behavior, Roswell
Park Cancer Institute, Elm and
Carlton Streets, Buffalo, NY
14263, USA; andrea.licht@
roswellpark.org
Received 22 February 2012
Revised 5 November 2012
Accepted 7 November 2012
To cite: Licht AS, Hyland A,
Travers MJ, et al.Tob
Control Published Online
First: 4 December 2012
doi:10.1136/tobaccocontrol-
2012-050493
ABSTRACT
Objective This paper considers the evidence on
whether outdoor secondhand smoke (SHS) is present in
hospitality venues at high levels enough to potentially
pose health risks, particularly among employees.
Data sources Searches in PubMed and Web of
Science included combinations of environmental tobacco
smoke, secondhand smoke, or passive smoke AND
outdoor, yielding 217 and 5,199 results, respectively
through June, 2012.
Study selection Sixteen studies were selected that
reported measuring any outdoor SHS exposures
(particulate matter (PM) or other SHS indicators).
Data extraction The SHS measurement methods were
assessed for inclusion of extraneous variables that may
affect levels or the corroboration of measurements with
known standards.
Data synthesis The magnitude of SHS exposure
(PM
2.5
) depends on the number of smokers present,
measurement proximity, outdoor enclosures, and wind.
Annual excess PM
2.5
exposure of full-time waitstaff at
outdoor smoking environments could average 4.0 to
12.2 μg/m
3
under variable smoking conditions.
Conclusions Although highly transitory, outdoor SHS
exposures could occasionally exceed annual ambient air
quality exposure guidelines. Personal monitoring studies
of waitstaff are warranted to corroborate these modeled
estimates.
BACKGROUND
Secondhand smoke (SHS) is a rich source of sus-
pended fine particulates and is a significant con-
tributor to total particulate load in indoor
environments where smoking occurs.
1
An elevation
of 10 mg/m
3
of long-term exposure to fine particle
air pollution (particulate matter (PM)
2.5
), including
that from tobacco smoke, is associated with 6%,
9% and 14% increased risk for all cause, cardiopul-
monary and lung cancer mortality respectively.
2
Indoor smoke-free air laws have had lasting and
important health benefits including improved
indoor air quality, reductions in SHS exposure and
tobacco use, and lower rates of respiratory and car-
diovascular events.
3
Less than 11% of the world
population is protected by a comprehensive
smoke-free air policy covering 100% of all non-
hospitality workplaces, bars and restaurants.
4
Nevertheless, in recent years there has been a nor-
mative shift with regard to smoking in public
indoor places in which today, 28 countries have
country-wide comprehensive smoke-free air laws
present.
5
However, as jurisdictions implement
indoor smoke-free legislation, the outdoor areas of
such locations may become more commonly cited
sources of SHS exposure as smoking gets pushed
outdoors.
67
Globally, outdoor smoking restrictions are
uncommon,
8
though one of the most widespread
outdoor smoking bans occurred in New York City
in 2011 when smoking was banned in all parks,
beaches and pedestrian plazas.
9
Given the limited
research linking exposures to SHS from outdoor
environments to health effects, many current pol-
icies have been justified by citing preservation of
public amenity, the potential impacts on social
norms surrounding smoking, or litter reduction
rather than an overt concern to protect the health
of those exposed to SHS.
9–13
Moreover, in commu-
nities where indoor smoke-free air laws are already
present, surveys have shown that large proportions
of respondents would express preference for add-
itional smoke-free policies, such as those in
outdoor areas of dining establishments.
14–18
Assessment of the health consequences of SHS
exposure has been dominated by long-term expos-
ure studies conducted in indoor settings where SHS
concentrations can remain high, long after active
smoking has ceased.
19
However, mean outdoor
SHS exposures are highly dependent on external
factors and must be averaged over several transient
peaks occurring only during active smoking. Thus,
the total SHS exposure level received per cigarette
will be greater in indoor spaces compared with
exposures from cigarettes smoked outdoors.
19
Regardless, acute health effects have been asso-
ciated with short-term, low level SHS exposure.
Even very low concentrations (4.4 μg/m
3
) of envir-
onmental tobacco smoke (measured in PM
2.25
)
were found to facilitate eye, nasal and throat irrita-
tions among non-smokers.
20
Potentially more
serious acute effects on respiratory
21
and cardiovas-
cular health have been observed, such as impaired
flow-mediated vasodilation in healthy non-
smokers,
22
endothelial cell morbidity,
23
or platelet
aggregation in non-smokers.
23 24
Additionally, fre-
quent SHS exposure is also independently asso-
ciated with preclinical atherosclerosis.
25 26
Emerging research has suggested that under spe-
cific conditions, SHS levels can be temporarily
comparable with or even temporarily higher than
levels observed indoors.
27–33
However, if average
SHS levels are high enough to produce ill health
effects, they are likely to be more pronounced
among employees working in outdoor areas where
smoking is allowed due the higher frequency of
exposures experienced across working shifts and
overtime. The purpose of this review is to describe
the factors that can contribute to higher SHS
exposure levels, particularly in outdoor hospitality
Licht AS, et al.Tob Control 2012;0:1–8. doi:10.1136/tobaccocontrol-2012-050493 1
Review
TC Online First, published on December 5, 2012 as 10.1136/tobaccocontrol-2012-050493
Copyright Article author (or their employer) 2012. Produced by BMJ Publishing Group Ltd under licence.
group.bmj.com on December 5, 2012 - Published by tobaccocontrol.bmj.comDownloaded from
venues, and to estimate the levels of SHS exposure that may be
experienced by wait staff working at typical outdoor hospitality
venues.
METHODS
Searches were conducted in June 2012 using the search strings
Topic=(‘environmental tobacco smoke’) OR Topic=(‘SHS’)OR
Topic=(‘passive smoking’) AND Topic=(outdoor) in Web of
Science and (((environmental tobacco smoke (Title/Abstract))
OR SHS (Title/Abstract)) OR passive smoking (Title/Abstract))
AND outdoor (Title/Abstract)) in PubMed, yielding 5199 and
217 results, respectively. Review of the abstracts yielded only 16
studies that dealt either exclusively or partly with the direct
measurement of outdoor SHS levels. Secondary searches of the
references in these papers were conducted, but no further peer-
reviewed papers were located.
Of these 16 studies found in the peer-reviewed literature, 6
were completed in non-hospitality settings.
73134–37
Although
evidence from these studies has been considered, the focus of
this paper is on SHS exposure levels observed at outdoor areas
of hospitality, or hospitality-like settings. Two studies reported
on overlapping results,
632
with the latter updating previous
results to include more venues and time point assessments.
Reviewed studies, dated between 2007 and 2011, were from the
USA (n=5), Australia (n=3), New Zealand (n=3), Canada
(n=2), Spain (n=2) and Denmark (n=1). A table summarising
all peer-reviewed studies is available as web only material (see
online supplementary appendix A).
Although the primary conclusions in this report are based on
the peer-reviewed literature, non-peer reviewed studies (grey lit-
erature) consisting of conference proceedings, abstracts and
reports not apparently published in indexed journals were also
reviewed. These were obtained via contact with colleagues in
the field and searches of personal research collections. The 7
studies found in the grey literature are only considered as sup-
plementary evidence.
19 33 38 39–42
Using the data obtained from the experimental and observa-
tional studies in the peer-reviewed literature, estimates of excess
PM
2.5
exposure were calculated. These estimates are meant to
approximate the above-background PM
2.5
exposure levels that
may be experienced by employees working at typical
smoking-allowable outdoor hospitality venues. The online sup-
plementary appendix B provides the calculations used.
RESULTS
Measuring SHS contamination in outdoor settings
Given the complex nature of SHS, direct measurements are dif-
ficult to obtain. However, multiple methodologies have been
developed to measure representative components of SHS as
proxies for overall exposure. One such component, nicotine,
has been measured extensively using the nicotine concentration
present in the air
38
and the individual biological dose received,
though cotinine, a nicotine metabolite.
43–45
However, airborne
nicotine concentrations may not necessarily reflect that of other
constituents of SHS,
46
and ‘between-individual’differences in
nicotine metabolism have been noted.
44 45
Other studies have
measured specific carcinogenic components of SHS, such as par-
ticulate polycyclic aromatic hydrocarbons (PPAH)
47
or the
tobacco-specific carcinogen 4-(methylnitrosamino)-1-(3-
pyridyl)-1-butanol
48
as proxies for SHS exposure. The resulting
exposures levels obtained by the use of biomarkers like cotinine
or other carcinogenic compounds are representative of all cumu-
lative exposures over a given time period. This can make it diffi-
cult to differentiate exposures of interest, such as exposures
from outdoor sources of SHS exposure, from other exposures
experienced over the same period of time.
Measurement of airborne PM, yet another component of SHS,
is the most common method to assess SHS exposure. Although
particles less than 2.5 microns in diameter (PM
2.5
) are not spe-
cific to particles originating from combustion of tobacco pro-
ducts, a substantial amount is released from burning cigarettes,
and such measurements have been validated as a method for
assessing SHS exposure indoors.
49 50
Of the 16 studies found in
the peer reviewed literature assessing outdoor SHS levels, 13
elected to measure PM
2.5
levels (see online supplementary
appendix A). The remainder of this paper focuses on SHS expo-
sures measured by PM
2.5
.
Observed levels of SHS contaminants in outdoor areas
Experimental studies can provide valid means to quantify
outdoor tobacco smoke (OTS) levels under controlled scenarios.
Two studies by Klepeis and colleagues quantified exposures and
addressed the effects of proximity to the source and varying
wind speeds and directions on OTS concentrations.
27 51
Controlled experiments conducted at a private residence by
Klepeis and colleagues used clusters of various monitors
(Photoelectric aerosol sensors (PAS), laser counters (GRIMM)
and Nephelometers (NEPH)). Measurements were converted
from each respective monitor’s native unit to measure respirable
suspended particle (RSP) mass concentrations in μg/m
3
which is
a close approximation of PM
2.5
.
27
Monitor clusters were placed
on opposite sides of smolder-smoked cigarettes at distances
between 0.25 and 4 m away. ‘Smoking’sessions used 3–5 cigar-
ettes burned successively. During periods of active ‘smoking’the
overall average OTS particle levels ranged from 10–22 mg/m
3
(NEPH) to 38–61 mg/m
3
(PAS) across all distances over 10 min
experimental periods. These results were likely influenced by a
‘microplume effect’, in which highly transitory peaks, some
exceeding 1000 mg/m
3
, were observed in close proximity to
active smoking sources.
Follow-up experiments by Klepeis and colleagues used carbon
monoxide (CO) as a tracer gas to better understand human
exposures to air pollutants occurring within short distances
from a point source in ground-level outdoor environments.
51
CO was released from a central point at known emission rates
while surrounding sensors measured CO concentrations in a
three-dimensional array at various heights and distances away.
Precise wind speeds and directions were continuously monitored
and recorded. Based on these experiments, statistical modelling
approaches were developed to estimate air concentrations for
other pollutants and source emission rates, such as those arising
from OTS particle exposures. The average RSP particle concen-
tration due to OTS was estimated to be 70–110 mg/m
3
, calcu-
lated using the reported average fine particulate emission rate of
cigarettes (1.4 mg/min), the normalised average single direction
concentration of 50–80 mg/m
3
per mg/min (from CO experi-
ments), and a range of horizontal distances of 0.25–0.5 m.
Although these experimental studies provide evidence of
emissions from single point sources under controlled scenarios,
they may not be fully applicable to real world hospitality-like
settings. Observational studies may provide additional empirical
evidence about factors that may temporarily influence SHS
(PM
2.5
) exposures in outdoor hospitality venues. In particular,
four observational studies in the peer reviewed literature pro-
vided the most detailed information on such factors.
28–30 52
Three of these studies collected PM
2.5
data using the TSI SidePak
AM510 monitor, applying a calibration factor of 0.32 (unit-less)
to the raw data to correct for properties related to SHS.
28–30
A
2 Licht AS, et al.Tob Control 2012;0:1–8. doi:10.1136/tobaccocontrol-2012-050493
Review
group.bmj.com on December 5, 2012 - Published by tobaccocontrol.bmj.comDownloaded from
fourth study measured real-time PM
2.5
levels using the DustTrak
(TSI, Incorporated: Shoreview, Minnesota, USA) monitor, also
applying a calibration factor of 0.32 to the raw data.
52
Cameron et al collected data within 1 m of active smokers at a
convenience sample of 69 outdoor dining areas in Melbourne,
Australia.
29
Mean ambient levels were 8 mg/m
3
.PM
2.5
levels
averaged 18 mg/m
3
across the total observation time period
(average of 25.8 min/venue) and 27 mg/m
3
when active smoking
was present (averaged over 10 min). After accounting for
ambient concentrations, smoking in these outdoor patios contrib-
uted an average excess above ambient levels of nearly 10 mg/m
3
of particulates over the entire measurement period.
Stafford et al
30
measured PM
2.5
levels in 28 alfresco cafes and
pubs in Perth and Mandurah, Australia. Mean PM
2.5
levels for
none, one and two or more smokers were 3.98, 10.59 and
17.00 mg/m
3
, respectively, with the weighted average PM
2.5
con-
centration over ‘smoking present’periods being 14 mg/m
3
(total of
388 smoking min logged). After adjusting for background levels
(3.98 mg/m
3
), active smoking outdoors contributed a 10 mg/m
3
boost in PM
2.5
levels across the entire measurement period. A limi-
tation of this study is that data on distance or position of the
smokers relative to the monitor was not collected. Although this
study did include an indicator of wind conditions, it was unclear
how wind speeds were assessed, and direction was not reported.
Brennan et al examined changes in outdoor and indoor air
quality levels after implementation of an indoor smoking ban in
Melbourne, Australia.
28
Outdoor hospitality venues visited were
semi-enclosed with direct access to indoor areas (n=19).
Concurrent outdoor and indoor monitoring occurred for
30 min at each venue within 5 m of the indoor-outdoor access
point. Contrary to predictions, geometric mean (GM) outdoor
PM
2.5
levels decreased 38% after implementation of the
smoking ban (from 19.0 mg/m
3
to 13.1 mg/m
3
), while adjusting
for ambient PM
2.5
levels (5 mg/m
3
). The observed mean
smoking prevalence outdoors increased from pre- (6.2%) to
post-ban (7.3%) (p=0.401). However, the smoking prevalence
indoors at the pre-ban assessment (4.7%) was already lower
than the prevalence outdoors (6.2%), suggesting that smoking
behaviours may have already shifted outdoors prior to the ban.
This may explain why the smoking prevalence outdoors did not
significantly increase at the post-ban assessment.
A study by St. Helen and colleagues from the U.S. observed
outdoor PM
2.5
levels at fivehospitalityvenuesmeasuredonupto
four separate occasions. Mean PM
2.5
levels at three locations (Bar 1:
63.9 mg/m
3
, Bar 2: 51.0 mg/m
3
, and Restaurant 1: 39.7 mg/m
3
)were
foundtobesignificantly elevated above ambient levels (20.4 mg/m
3
,
p<0.0001). After adjusting for vehicular traffic near venues, the
number of smokers present remained the only statistically significant
predictor of Log(PM
2.5
) levels, indicating that SHS exposures are the
likely source of PM
2.5
levels observed at outdoor areas of hospitality
venues. However, this study did not adjust for other factors that are
known to influence PM
2.5
levels such as the presence of partial
enclosures or the proximity of smokers to the monitors, and may
also be limited by the inclusion of a small number of venues.
52
Other observational studies have come to similar conclusions,
but the findings should be interpreted cautiously. Compared
with other studies,
28–30 52
outdoor PM
2.5
levels were observed
to be much higher in studies by Wilson and colleagues.
632
In
four randomly selected outdoor smoking areas of hospitality
venues, an average of four lit cigarette present produced mean
PM
2.5
levels of 36 mg/m
3
(range 19–75) while ambient concen-
trations averaged 14 mg/m
3
. In two purposefully selected
outdoor areas with a higher degree of enclosure, mean PM
2.5
levels were 65 and 182. Data concerning many external factors
that could affect these levels, such as monitoring proximity,
were not provided, and the inclusion of only four study sites
limits the use of this data. However, this study does highlight
that increasing the degree of enclosure of an ‘outdoor’space
can dramatically increase PM
2.5
levels.
There is also evidence to suggest that OTS can drift indoors,
compromising indoor smoke-free environments.
672832–35 39
In
addition, once tobacco smoke has drifted indoors, it does not
dissipate as quickly as it would in outdoor environments.
39
However, most of these studies did not specify the distance
from entrances to monitors or other factors such as traffic
between areas and the presence of open or closed doors, com-
promising the ability to make valid assessments of this data.
In summary, several key findings are obtained from these
studies: (1) observational studies estimate that exposure to SHS
outdoors adds approximately 10 mg/m
3
or more of excess PM
2.5
exposure; (2) although exposures are almost always highly tran-
sitory, experimental studies find that excess exposure levels can
exceed estimated levels obtained from observational studies by
an order of magnitude; (3) it may be possible for outdoor to
indoor SHS drift leading to contamination of indoor smoke-free
environment; and (4) outdoor PM
2.5
concentration can be
similar to levels observed in indoor smoking allowable areas,
but these levels are highly influenced by external factors.
Influence of external factors on levels of exposure to SHS
contaminants
Number of lit cigarettes
Resu lts from Zhang, et al showed that increasing numbers of lit
cigarettes per 1000 ft
2
of patio area (0, 1.0–4.3, 4.4–8.7, 8.8–16.7
and 16.8–41.7 lit cigarettes) increased the GM PPAH levels from
4.7 mg/m
3
(no cigarettes) to 9.1, 16.9, 19.1 and 27.0 mg/m
3
,
respectively.
47
Although regression models by Stafford et al only
predicted about 40% of the overall variance in PM
2.5
, the number
of active smokers present was found to be the greatest contributor
to the variance.
30
Other multivariate modelling by Brennan found
that an increase of one in the number of mean lit cigarettes was
associated with a 25% increase in GM outdoor PM
2.5
.
28
After
adjusting for pedestrian and vehicle traffic, St. Helen and collea-
gues found that lit cigarettes at or passing by outdoor study sites
significantly increased log (PM
2.5
) levels.
52
Distance from monitor to point source
Most studies assessing the distance between active smoking and
a monitoring device have demonstrated a proximity effect.
Experimental work has found that RSP levels were approxi-
mately halved for each doubling of distance from the point
source,
27 51
but approached ambient levels at distances >2 m.
51
Based on regression modelling by Cameron, cigarettes smoked
at distances >1 m from a monitor did not significantly predict
overall PM
2.5
levels (p=0.261).
29
Outdoor SHS levels have
been found to be roughly equal to or greater than indoor SHS
levels at very close distances (<0.5 m).
27
Although wait staff are
often in close proximity to customers, such distances may not
be applicable to real world exposures between smoking and
non-smoking individuals at typical smoking-allowable outdoor
areas of hospitality venues.
Wind conditions
Only two observational studies reported on wind conditions, but
they were based solely on observations made by data collectors
and thus should not be used in making conclusions.
30 40
Controlled experiments completed indoors utilising a fan to
blow smoke plumes at a constant speed of 0.4 m/s found that
Licht AS, et al.Tob Control 2012;0:1–8. doi:10.1136/tobaccocontrol-2012-050493 3
Review
group.bmj.com on December 5, 2012 - Published by tobaccocontrol.bmj.comDownloaded from
RSP levels were approximately three times higher downwind
relative to upwind levels.
27
Outdoors, wind observed to blow the
smoke plume from smolder-smoked cigarettes in a single direc-
tion at approximately 0.5 m/s lead to mean downwind PM
2.5
levels of 130 mg/m
3
measured at 0.6 m away. Mean RSP levels
were still elevated above background levels by 13–41 mg/m
3
at
further downwind distances away (1.7–2.7 m), while RSP levels
measured at 0.6 m upwind to smolder-smoked cigarettes were
nearly zero (2 mg/m
3
).
27
Normalised average CO concentrations were observed to fall
by one-third to one-half as average wind speeds increased from
<0.2 m/s to 0.2–0.5 m/s.
51
While CO concentrations
approached ambient levels at horizontal distances of about 2 m,
this distance may be somewhat extended under low wind condi-
tions (<0.2 m/s), possibly resulting in 30–50% higher concen-
trations downwind nearby active smoking.
51
Partial enclosures
Enclosures such as walls, fences, garden umbrellas and roofs can
substantially influence exposures to SHS in outdoor areas. These
conditions may lead to ‘street canyon’effects which are charac-
teristic of unobstructed air movement along building boundaries
resulting in windier conditions and higher levels of ventilation.
Conversely, partially enclosed areas may contain SHS to a
greater degree.
27
The purposeful monitoring of two highly
enclosed ‘outdoor’smoking areas in New Zealand demonstrated
the influence of SHS exposures under these conditions; mean
levels were found to be 124 mg/m
3
compared with only 36 mg/
m
3
from open air smoking areas.
32
Although Brennan and col-
leagues found no association between outdoor air quality and
the level of enclosure,
28
two studies estimate that outdoor over-
head coverage can increase SHS levels by about 50–70%.
27 29
From unpublished literature, mean PM
2.5
levels in outdoor
hospitality venues in Vancouver, BC ranged from 6 to 430 μg/
m
3
, although many of these venues had complete roof coverings
and nearly complete wall coverings.
41
High, yet transitory peak
10-s PM
2.5
level were also found in a fairly enclosed outdoor
courtyard (716 μg/m
3
)
40
and levels were also elevated under
patio and table umbrellas.
39 40 42
Measured outdoor SHS contaminants compared with
established air quality benchmarks
The WHO provides guidelines for short (24-h) and long term
(annual) PM exposures.
53
Guidelines for ambient air quality,
including PM and other harmful components are also provided
by factions within individual countries, such as the US
Environmental Protection Agency (EPA) and Australia’s
National Environment Protection Council.
54 55
Table 1 presents
the ambient air quality standards for total particulates for the
WHO, the USA and Australia.
Air monitoring of short-term exposures to PM arising from
transient outdoor exposures such as SHS are likely to produce
low 24-h or annually averaged exposures due to intermittent
and typically short exposure periods. No guidelines or standards
are presently available for such intermittent exposure to PM
2.5
,
but some studies have attempted to estimate 24-h or annual
PM
2.5
exposure from outdoor SHS using the aforementioned
guidelines
6273251
or the US Air Quality Index.
30 41 56
These
standards were devised for total ambient air pollution which has
a different composition than tobacco-specific pollution.
27
However, the fundamental issue is whether such transient
outdoor SHS exposures are sufficient to exceed such guidelines,
thus making a stronger case to warrant the need for outdoor
smoke-free legislation. Although studies using personal-level air
monitoring may better describe individual SHS exposures in
outdoor smoking-allowable areas, such data is currently unavail-
able. In the interim, short term exposure levels can be estimated
using data reported in observational and experimental studies,
as summarised below.
Observational studies
Three observational studies of outdoor bar and restaurant areas
suggest that PM
2.5
levels are elevated by approximately 10 mg/m
3
during times when active smoking occurs.
28–30
Such studies may
not accurately account for meteorological or proximity factors,
but it is unlikely that the aforementioned 24-h or annual guide-
lines for PM
2.5
exposure would be exceeded based on these
estimates.
Experimental studies
Experimental studies may provide more precise measurements
of external factors. However, modelled assumptions may under-
or over-estimate the true occupational exposures from SHS as
they may not reflect real-world exposures. Nevertheless, work
by Klepeis et al
27
estimated that the EPA 24-h standard for fine
particulates could be exceeded if an individual experienced as
few as nine cigarette events, each lasting approximately 10 min
at a downwind distance of 0.3 m. However, this estimate was
based on levels obtained from one very short measurement
period (10-min), at a close distance to a smoker, limiting the
generalisability of this estimate.
Later work by Klepeis estimated an occupational 24-h particle
exposure to wait staff working in smoking-allowable outdoor
patios to be 23.7 mg/m
3
.
51
This estimate assumed approximately
100 min of total OTS exposure, very close proximity to the
smoking patron (0.25 m), and exposures contributed by the
presence of only one smoking patron at tables directly served by
the worker. From these estimates, however, the 24-h standards
for PM
2.5
exposures would likely be exceeded only if extra-
occupational PM
2.5
exposures are assumed.
51
Table 1 Maximum ambient particulate concentration standards from Australia (‘Air NEPM’), the USA (NAAQS), and the WHO
Pollutant Averaging period WHO (mg/m
3
) USA (mg/m
3
) Australia (mg/m
3
)
PM
10
particles 24 h 50 150 50
PM
2.5
particles 24 h 25 35 25
1 year 10 15 8
Source (AU): http://www.environment.gov.au/atmosphere/airquality/standards.html#air.
Source (US): http://www.epa.gov/pm/standards.html.
Source (WHO): http://whqlibdoc.who.int/hq/2006/WHO_SDE_PHE_OEH_06.02_eng.pdf.
NAAQS, National Ambient Air Quality Standards; PM, particulate matter.
4 Licht AS, et al.Tob Control 2012;0:1–8. doi:10.1136/tobaccocontrol-2012-050493
Review
group.bmj.com on December 5, 2012 - Published by tobaccocontrol.bmj.comDownloaded from
Estimated projections combining observational and experimental
research
Due to the inherent limitations of both the observational and
experimental studies, combining data from each study type may
provide the most valid and reliable estimates of daily and annual
occupational outdoor SHS exposures. From observational studies,
a typical outdoor hospitality worker in a smoking-allowable area
may be exposed to active smoking between 40%
29
and 70%
30
of
their total working time, or about the SHS equivalent of 0.4–0.7
lit cigarettes at any given time from varying distances and angles.
Particulate concentrations at varying directions and wind
speeds can be obtained from experimental data (Klepeis et al,
table 3, page 3165).
51
Assuming light winds (0.1 m/s), the
average air pollution concentration from an arbitrary source
averaged over all distances and angles was 42.8 mg/m
3
(see
online supplementary appendix B).
51
This figure can be manipu-
lated to resemble OTS pollution using exposure data on the
presence of active smoking from observational studies
29 30
and
the fine particle emission rate for a cigarette (1.4 mg/min).
57
From this data, the excess PM
2.5
exposures from OTS incurred
over typical working shifts can be estimated and compared with
24-h and annual exposure guidelines.
Table 2 estimates the 24-h and annual PM
2.5
exposures from
occupational OTS exposures using sensitivity analyses for lower
(0.4 lit cigarettes present at all times), moderate (0.7 lit cigarettes
present at all times) and higher (1.0 lit cigarette present at all times)
SHS exposure conditions. After accounting for ambient PM
2.5
levels averaged from observational studies (6. 5 mg/m
3
), the excess
occupational OTS attributable PM
2.5
exposure for an 8-h shift was
calculated to be 17.5 mg/m
3
under the lower smoking exposure
condition, 35.4 mg/m
3
under the moderate smoking exposure con-
dition, and 53.4 mg/m
3
under the higher smoking exposure condi-
tion (see online supplementary appendix B).
The 24-hour and annual estimates are presented for occupa-
tional exposures with varying time spent working outdoors
(4-hour vs 8-hour shifts). Depending on the smoking exposure
conditions present, part-time employees working 4-hour shifts
outdoors may experience between 2.9 mg/m
3
(lower exposure)
and 8.9 mg/m
3
(higher exposure) of excess 24-hour PM
2.5
exposure attributable to outdoor occupational SHS. Among full
time workers (8-hour shifts), this would equate to between
5.8 mg/m
3
and 17.8 mg/m
3
added over a 24-hour period. At
the highest exposure condition assessed, this equates to an esti-
mated annual excess of 6.1 mg/m
3
(part time) to 12.2 mg/m
3
(full time) of added PM
2.5
exposure attributable to outdoor
occupational tobacco smoke exposures, above and beyond
ambient levels.
These calculated estimates suggest that it is unlikely for
outdoor occupational SHS exposure alone to exceed any of the
aforementioned guidelines for 24-hour PM
2.5
exposure.
Although it may be plausible that such exposures could occa-
sionally exceed the annual PM
2.5
exposure guidelines, this was
only under the highest modelled exposures.
Of note, the average outdoor air pollutant concentrations cal-
culated from the Klepeis et al
51
data are averaged across a large
distance from the emission source (0.25–4m) to reflect the
varying nature of exposure due to movement of wait staff.
However, all distances were weighted equally in creating this
measure, possibly resulting in an underestimate of the true
exposure as studies have shown that concentrations decrease as
a function of distance to the point source.
CONCLUSIONS
Together, these studies suggest that typical outdoor dining or
drinking areas of bars and restaurants can lead to elevated levels
of SHS exposure for both patrons and workers. Although OTS
is far more transient than indoor tobacco smoke, patrons and
staff can be briefly exposed to high concentrations of tobacco-
generated PM
2.5
under certain conditions. Evidence from the
studies presented here suggests that these levels may occasionally
Table 2 Estimates of 24-hour and Annual PM
2.5
exposures (in μg/m
3
) attributed to occupational outdoor tobacco smoke (OTS) under lower,
moderate, and higher exposures
Lower exposure Moderate exposure Higher exposure
Wind condition 0.1 m/s 0.1 m/s 0.1 m/s
Length of shift worked outdoors 4 h 8 h 4 h 8 h 4 h 8 h
Number of lit cigarettes present at all times†0.4
lit cigarettes
0.4
lit cigarettes
0.7
lit cigarettes
0.7
lit cigarettes
1.0
lit cigarette
1.0
lit cigarette
Cigarette emission factor (CEF) (constant)‡1.4 mg/min 1.4 mg/min 1.4 mg/min 1.4 mg/min 1.4 mg/min 1.4 mg/min
Total cigarette emissions (# lit cigarettes* CEF) 0.56 mg/
cigarette
0.56 mg/
cigarette
0.98 mg/
cigarette
0.98 mg/
cigarette
1.4 mg/
cigarette
1.4 mg/
cigarette
Average air pollution concentration across all distances
and angles§
42.8 μg/m
3
42.8 μg/m
3
42.8 μg/m
3
42.8 μg/m
3
42.8 μg/m
3
42.8 μg/m
3
Average exposure for 8-hr Shift* 24.0 μg/m
3
24.0 μg/m
3
41.9 μg/m
3
41.9 μg/m
3
59.9 μg/m
3
59.9 μg/m
3
Assumed ambient air concentration (constant)¶ 6.5 μg/m
3
6.5 μg/m
3
6.5 μg/m
3
6.5 μg/m
3
6.5 μg/m
3
6.5 μg/m
3
Excess exposure above ambient air concentration* 17.5 μg/m
3
17.5 μg/m
3
35.4 μg/m
3
35.4 μg/m
3
53.4 μg/m
3
53.4 μg/m
3
24-h excess PM
2.5
Exposure from occupational OTS* 2.9 μg/m
3
5.8 μg/m
3
5.9 μg/m
3
11.8 μg/m
3
8.9 μg/m
3
17.8 μg/m
3
Annual excess PM
2.5
exposure from occupational OTS* 2.0 μg/m
3
4.0 μg/m
3
4.0 μg/m
3
8.1 μg/m
3
6.1 μg/m
3
12.2 μg/m
3
*See appendix B, uploaded as ‘Web Only’material, for an explanation of all calculations.
†From Cameron et al
29
: active smoking was present 38.4% of the total observation time; From Stafford et al
30
, active smoking was present 71.2% of the total observation time. The
higher exposure category is an estimate of when one cigarette is present at all times over the entire 8 h shift.
‡Klepeis et al
57
first reported the average fine particulate emission rate for cigarettes of 1.4 mg/min.
§Klepeis et al
51
—this figure (42.8 μg/m
3
) was calculated from table 3 using light wind (0.1 m/s) speeds
¶Ambient levels averaged 6.5 μg/m
3
across observational studies, which were usually measured at off-site locations where no smoking was observed to occur. Brennan: 5 μg/m
3
,
Cameron: 8 μg/m
3
, Perry: 6 μg/m
3
, Stafford: 4 μg/m
3
, Wilson et al
32
:14μg/m
3
, and Wilson et al
6
:2μg/m
3
.
PM, particulate matter.
Licht AS, et al.Tob Control 2012;0:1–8. doi:10.1136/tobaccocontrol-2012-050493 5
Review
group.bmj.com on December 5, 2012 - Published by tobaccocontrol.bmj.comDownloaded from
be equivalent to or higher than levels observed in indoor setting
when smoking is permitted at close proximity.
Due to outdoor weather conditions and dispersion effects,
tobacco-originating PM
2.5
exposure levels have been shown to
drop sharply under most conditions at distances greater than
2 m from a single point source. However, outdoor areas of bars
or restaurants often have more than one smoker present, poten-
tially contributing to higher SHS concentrations. As a result,
this 2 m radius may be substantially extended due to dense table
placement, a greater number of active smokers, single direc-
tional and light wind speeds, and other factors such as partial
wall or roof coverings. Although partial smoke-free policies may
be practical and enforceable in some outdoor settings where
movement by both patrons and wait staff is at a minimum, they
may be particularly inadequate in limiting SHS exposures for
both patrons and workers in settings where patrons are mobile,
such as beer gardens or outside areas of bars.
Popeandcolleaguesestimatethatanincreaseof5–10 mg/m
3
in
average annual PM
2.5
exposure is associated with a 3–6%
increased risk in all-cause mortality.
2
Similarly, increases in annual
PM
2.5
exposures are also associated with increased risk of cardio-
pulmonary and lung cancer mortality.
58
As our calculated annual
estimates of excess PM
2.5
exposures attributable to OTS ranged
from 2.0–12.2 mg/m
3
under varying exposure conditions, it may
be plausible for staff working in smoking-allowable outdoor areas
to present with ill health effects from such occupational exposures.
However, personal monitoring studies are necessary to corrobor-
ate these calculated estimates.
The studies presented here have reported that patrons and
staff have highly variable SHS exposure levels in outdoor
drinking or dining areas of bars, restaurants or pubs.
Moreover, not only did exposure vary by location, but SHS
levels could be highly variable within the confines of a single
venue. Because these studies used stationary monitors, it not
feasible to assess the variation in SHS exposure experienced by
wait staff during the course of a typical work day. However, to
date, no personal monitoring studies of wait staff in outdoor
settings have been conducted to corroborate the modelled esti-
mates of staff exposures in these worksite settings. Such studies
may be inherently challenging due to higher costs, difficulty in
recruitment of individual wait staff, securing agreement for par-
ticipation from businesses, or the potential for changes in beha-
viours of both wait staff and patrons due to monitoring
activities.
Additional studies were found that assessed PM
2.5
exposures in
non-hospitality settings such as outside of buildings, walking on
city streets or in semi-enclosed bus shelters.
73134–37
However, the
estimates presented in this paper are based on observational
studies of hospitality settings and experimental studies simulating
hospitality-like settings. Therefore, it may not be appropriate to
generalise these estimates to other outdoor settings where expo-
sures are likely to be different. Similar studies assessing outdoor
SHS exposures in parks, beaches, or other outdoor settings are
warranted to support exposure-based legislation aimed at
restricting smoking in these locations.
Limitations of the paper, particularly the calculation pre-
sented in table 2, do exist, the first of which is the extrapola-
tion of the experimental studies to the real-world scenarios
used in our calculations. Smolder-smoked cigarettes, used in
experimental studies, generate SHS that is comprised only of
sidestream smoke, while SHS from free-range smoked cigar-
ettes contains a mixture of sidestream and exhaled mainstream
smoke. At least initially, the median particle size of sidestream
smoke is smaller than that of the particles of mainstream
smoke.
59
Therefore, it is plausible that PM
2.5
exposure levels
generated from experimental studies using smolder-smoked
cigarettes may overestimate exposure levels generated if free-
range smoked cigarettes were used. However, given that side-
stream smoke is estimated to contribute higher particle yields
in SHS,
59 60
the degree of difference is not expected to be
very large. Additionally, the results obtained from the experi-
mental studies
27 51
provide the most comprehensive informa-
tion on the factors that are most likely to influence SHS levels
outdoors. Another limitation is that these findings are based on
measurements that have been obtained from a wide range of
‘outdoor’areas of hospitality settings, from fully open-air to
highly enclosed, potentially limiting the consistency between
individual studies. Although several assumptions were made to
estimate the excess exposures to PM
2.5
, these estimates may be
used as a guide for potential excess exposure levels at typical
outdoor hospitality settings.
Of note, this is not a systematic review. However, given the
limited available research on SHS exposure measurements in
outdoor settings, to the best of our knowledge, this review does
report on all available literature at the time of our initial search.
Furthermore, widening our search to include the MeSH term
for secondhand tobacco smoke, ‘Tobacco Smoke Pollution’did
not result in the identification of additional studies of interest.
Thus, the search criteria used was likely sufficient to identify all
relevant literature for this review.
Future research is needed to fully understand the potential
health effects from intermittent SHS exposures in outdoor
areas. Additionally, studies that incorporate both environmental
SHS exposure measurements and biomarkers may be war-
ranted to link the contribution of these intermittent SHS
exposures to actual internal dose and potential health effects.
The estimates obtained here suggest that it is unlikely for
PM
2.5
exposures from SHS alone in outdoor
smoking-allowable hospitality settings to exceed the aforemen-
tioned PM
2.5
guidelines. Although these estimates do not
incorporate non-tobacco PM
2.5
sources due to limitations of
the available data, SHS related PM
2.5
exposures from these
outdoor hospitality settings may be significant contributors to
overall 24-h or annual PM
2.5
exposure.
Policy-driven smoke-free policies have typically been
grounded in the prevention of adverse health effects to
non-users of tobacco products.
5
However, current evidence of
potential adverse health effects due to intermittent tobacco
smoke exposures at outdoor hospitality venues is weak. To
obtain a better evidence base for policy determination in these
locations, additional studies, including those employing personal
monitoring methods to ascertain more accurate SHS exposures
levels, are needed. Moreover, outdoor SHS exposure data in
non-hospitality settings is also warranted to support the imple-
mentation of smoking restrictions in other outdoor areas.
Important secondary, collateral benefits of smoke-free policies
may include the denormalisation of smoking, lower smoking ini-
tiation rates among youth, and reduced tobacco consumption
among adults.
12 13
Therefore, based on the limited data pre-
sented in this paper, it seems plausible to suggest that smoking
restrictions could be implemented in outdoor areas of bars and
restaurants where SHS exposures are fairly high and consistent,
as potential adverse health effects would likely be most pro-
nounced in such situations.
6 Licht AS, et al.Tob Control 2012;0:1–8. doi:10.1136/tobaccocontrol-2012-050493
Review
group.bmj.com on December 5, 2012 - Published by tobaccocontrol.bmj.comDownloaded from
What this paper adds
▸This paper is one of the first to review the evidence related to
secondhand smoke (SHS) exposure in outdoor areas of
hospitality venues. The findings show that under conditions
commonly experienced in these outdoor areas where people
are generally close together, SHS exposures can increase
average annual exposure to particulates for both patrons and
employees, putting them at increased risk of adverse health
effects.
Contributors SC and AH compiled much of the initial literature and wrote a Rapid
Review of the literature, commissioned by the Sax Institute, NSW Australia. Both
also contributed to writing of the current manuscript. From the initial rapid review
conducted by SC and AH, AL lead the current manuscript writing and completed the
calculations of daily and annual PM2.5 exposures presented in table 2. AL also
updated the initial review of the literature and formatted the paper for all
submissions. MJT compiled various grey literature sources and assisted with the
updated literature review and writing of the final manuscript. All authors reviewed
and accepted the final version(s) of the manuscript.
Funding Funding for this review was provided to author SC by the Sax Institute,
NSW Australia. Funding was also supported, in part, to author ASL by Award
Number R25CA113951 from the National Cancer Institute (NCI). The content is
solely the responsibility of the authors and does not necessarily represent the official
views of the National Cancer Institute or the National Institutes of Health.
Competing interests None.
Provenance and peer review Not commissioned; externally peer reviewed.
REFERENCES
1 U.S. Department of Health and Human Services. The health consequences of
involuntary exposure to tobacco smoke: a report of the surgeon general. Atlanta,
GA: U.S. Department of Health and Human Services, Centers for Disease Control
and Prevention, Coordinating Center for Health Promotion, National Center for
Chronic Disease Prevention and Health Promotion, Office on Smoking and Health,
2006.
2 Pope CA III, Burnett RT, Thun MJ, et al. Lung cancer, cardiopulmonary mortality,
and long-term exposure to fine particulate air pollution. JAMA 2002;287:1132–41.
3 Hahn EJ. Smokefree Legislation: A review of health and economic outcomes
research. Am J Prev Med 2010;39(Suppl 6):S66–76.
4 World Health Organization. WHO report on the Global Tobacco Epidemic, 2011.
Warning about the dangers of tobacco. Geneva, Switzerland: WHO Press, 2011.
5 Hyland A, Barnoya J, Corral JE. Smoke-free air policies: past, present and future.
Tob Control 2012;21:145–61.
6 Wilson N, Edwards R, Parry R. A persisting secondhand smoke hazard in urban
public places: results from fine particulate (PM2.5) air sampling. N Z Med J
2011;124:34–47.
7 Kaufman P, Zhang B, Bondy SJ, et al. Not just ‘a few wisps’: real-time
measurement of tobacco smoke at entrances to office buildings. Tob Control
2011;20:212–8.
8 Americans for Nonsmokers’Rights. Smokefree Lists, Maps and Data: Outdoor Area
Lists—As of April 1, 2011. http://www.no-smoke.org/goingsmokefree.php?id=519
(accessed 11 May 2011).
9 New York City Department of Health and Mental Hygiene. Press Release: Mayor
Bloomberg, Deputy Mayor Gibbs, Speaker Quinn, Council Member Brewer, Health
Commissioner Farley, and Parks Commissioner Benepe announce New York City public
parks, beaches, and pedestrian plazas are now smoke-free. 23 May 2011. http://www.
nyc.gov/portal/site/nycgov/menuitem.c0935b9a57bb4ef3daf2f1c701c789a0/index.jsp?
pageID=mayor_press_release&catID=1194&doc_name=http%3A%2F%2Fwww.nyc.
gov%2Fhtml%2Fom%2Fhtml%2F2011a%2Fpr172-11.
html&cc=unused1978&rc=1194&ndi=1 (accessed 26 May 2011).
10 Novotny TE, Lum K, Smith E, et al. Cigarettes butts and the case for an
environmental policy on hazardous cigarette waste. Int J Environ Res Public Health
2009;6:1691–705.
11 Novotny TE, Hardin SN, Hovda LR, et al. Tobacco and cigarette butt consumption in
humans and animals. Tob Control 2011;20(Suppl 1):i17–20.
12 Francis JA, Abramsohn EM, Park HY. Policy-driven tobacco control. Tob Control
2010;19:i16–20.
13 Voorhees CC, Ye C, Carter-Pokras O, et al. Peers, tobacco advertising, and
secondhand smoke exposure influences smoking initiation in diverse adolescents.
Am J Health Promot 2011;25:e1–e11.
14 Paul C, Paras L, Walsh R, et al. Tracking NSW Community Attitudes and Practices in
Relation to Tobacco: A biennial telephone survey. March, 2007, CHeRP: Newscastle.
http://www.ashaust.org.au/pdfs/NSWsurvey07.pdf (accessed 24 May 2011).
15 Kennedy RD. Evaluation of the City of Woodstock’s outdoor smoking by-law—A
longitudinal study of smokers and non-smokers. http://hdl.handle.net/10012/5397
(accessed 31 Jan 2012).
16 Thompson B, Coronado GD, Chen L, et al. Preferred smoking policies at 30 Pacific
Northwest colleges. Public Health Rep 2006;121:586–93.
17 New South Wales Health. New South Wales Population Health Survey 2008
(HOIST).http://www.health.nsw.gov.au/PublicHealth/surveys/hsa/08/toc/
t_2_beh_12_smoking.asp (accessed 24 May 2011).
18 Health Sponsorship Council. 2008 health and lifestyles survey: table of results.
Wellington: Health Sponsorship Council, 2009.
19 Repace J. Measurements of outdoor air pollution from secondhand smoke on the UMBC
campus. June 1, 2005. http://www.repace.com/pdf/outdoorair.pdf (accessed 26 Jan 2012).
20 Junker MH, Danuser B, Monn C, et al. Acute sensory response of nonsmokers at
very low environmental tobacco smoke concentrations in controlled laboratory
settings. Environ Health Perspect 2001;109:1045–52.
21 Flouris AD, Koutedakis Y. Immediate and short-term consequences of secondhand
smoke exposure on the respiratory system. Curr Opin Pulm Med 2011;17:110–15.
22 Giannini D, Leone A, Di Bisceglie D, et al. The effects of acute passive smoke
exposure on endothelium-dependent brachial artery dilation in healthy individuals.
Angiology 2007;58:211–17.
23 Davis JW, Shelton L, Watanabe IS, et al. Passive smoking affects endothelium and
platelets. Arch Intern Med 1989;149:386–9.
24 Burghuber OC, Punzengruber C, Sinzinger H, et al. Platelet sensitivity to prostacyclin
in smokers and non-smokers. Chest 1986;90:34–8.
25 Kallio K, Jokinen E, Saarinen M, et al. Arterial intima-media thickness, endothelial
function, and apolipoproteins in adolescents frequently exposed to tobacco smoke.
Circ Cardiovasc Qual Outcomes 2010;3:196–203.
26 Glantz SA, Parmley WW. Even a little secondhand smoke is dangerous. JAMA
2001;286:462–3.
27 Klepeis NE, Ott WR, Switzer P. Real-time measurement of outdoor tobacco smoke
particles. J Air Waste Manage Assoc 2007;57:522–34.
28 Brennan E, Cameron M, Warne C, et al. Secondhand smoke drift: examining the
influence of indoor smoking bans on indoor and outdoor air quality at pubs and
bars. Nicotine Tob Res 2010;12:271–7.
29 Cameron M, Brennan E, Durkin S, et al. Secondhand smoke exposure (PM2.5) in
outdoor dining areas and its correlates. Tob Control 2010;19:19–23.
30 Stafford J, Daube M, Franklin P. Second hand smoke in alfresco areas. Health
Promot J Austr 2010;21:99–105.
31 Hess DB, Ray PD, Stinson AE, et al. Determinants of exposure to fine particulate
matter (PM
2.5
) for waiting passengers at bus stops. Atmos Environ
2010;44:5174–82.
32 Wilson N, Edwards R, Maher A, et al. National smokefree law in New Zealand
improves air quality inside bars, pubs, and restaurants. BMC Public Health
2007;7:85.
33 Kennedy RD, Sendzik T, Elton-Marskall T, et al. Measuring SHS in Restaurants, Pubs,
and in Gaming Facilities: Tobacco Smoke Pollution in Outdoor Hospitality Settings-The
Results of PM2.5 Monitoring on Patios and Inside Bars (Proffered Paper). The 13th
World Conference on Tobacco or Health: Washington DC, USA, July 2006.
34 Sureda X, Fu M, Lopez MJ, et al. Second-hand smoke in hospitals in Catalonia
(2009): A cross-sectional study measuring PM2.5 and vapor-phase nicotine. Environ
Res 2010;110:750–5.
35 Sureda X, Martinex-Sanchez JM, Lopez MJ, et al. Secondhand smoke levels in public
building main entrances: outdoor and indoor PM2.5 assessment. Tob Control
2012;21:543–8.
36 BoffiR, Ruprecht A, Mazza R, et al. A day at the European Respiratory Society
Congress: Passive smoking influences both outdoor and indoor air quality. Eur
Respir J 2006;27:862–3.
37 Parry R, Prior B, Sykes AJ, et al. Smokefree Streets: A pilot study of methods to
inform policy. Nicotine Tob Res 2011;13:389–94.
38 California Environmental Protection Agency-Air Resource Board (ARB). Technical
support document for the “Proposed Identification of Environmental Tobacco Smoke
as a Toxic Air Component”: Appendix C—Near-source ambient air monitoring of
nicotine as a marker for environmental tobacco smoke. 14 October 2003. http://
www.arb.ca.gov/regact/ets2006/app3exe.pdf (accessed 26 Jan 2012).
39 Kennedy RD, Fong GT, Hyland AJ, et al. Tobacco Smoke Pollution on Outdoor Patios
—An Experimental Evaluation of the Smoke-Free Ontario Act: Presentation at the
Society for Nicotine and Tobacco 14th Annual Meeting, 2008 (Portland, OR, USA).
http://www.tobaccofreewny.com/smoke-free-outdoor-air-patios/ (accessed Jan 2012).
40 Kennedy RD. Smokefree Patios: A study of air quality on patios that permit or
restrict smoking in the city of Ottawa: Report to the Ottawa Council for Tobacco
and Health, 2010. http://www.ottawasansfumee.com/2006-en/pdfs/
newsConferenceBackgrounder.pdf (accessed 26 Jan 2012).
Licht AS, et al.Tob Control 2012;0:1–8. doi:10.1136/tobaccocontrol-2012-050493 7
Review
group.bmj.com on December 5, 2012 - Published by tobaccocontrol.bmj.comDownloaded from
41 TraversM,HigbeeC,HylandA.Vancouver Island outdoor tobacco smoke air monitoring
study, 2007.Buffalo,NY:RoswellParkCancerInstitute, 2007. http://tobaccofreeair.org/
documents/VancouverIslandOSAReport4-10-07.pdf (accessed 17 May 2011).
42 Kennedy RD, Fong GT. Outdoor Second-Hand Smoke: An Experimental Evaluation
of Tobacco Smoke Levels in Doorways. 6th National Conference on Tobacco or
Health (2009). Queen Elizabeth Hotel, Montreal Quebec.
43 Hall JC, Bernert JT, Hall DB, et al. Assessment of exposure to secondhand smoke at
outdoor bars and family restaurants in Athens, Georgia, using salivary cotinine.
J Occup Environ Hyg 2009;6:698–704.
44 Centers for Disease Control and Prevention (CDC) National Center for Environmental
Health (NCEH). Third National Report on Human Exposure to Environmental
Chemicals (NCEH publication No. 05-0570). Atlanta, GA, 2005. http://www.clu-in.
org/download/contaminantfocus/pcb/third-report.pdf (accessed 20 May 2011).
45 Jarvis MJ, Russell MA, Feyerabend C, et al. Passive exposure to tobacco smoke:
Saliva cotinine concentrations in a representative population of non-smoking
schoolchildren. Br Med J (Clin Resid Ed) 1985;291:927–9.
46 Benowitz NL. Cotinine as a biomarker of environmental tobacco smoke exposure.
Epidemiol Rev 1996;18:188–204.
47 Zhang B, Bondy S, Ferrence R. Do indoor smoke-free laws provide bar workers with
adequate protection from secondhand smoke? Prev Med 2009;49:245–7.
48 St. Helen G, Bernert JT, Hall DB, et al. Exposure to secondhand smoke outside of a
bar and a restaurant and tobacco exposure biomarkers in nonsmokers. Environ
Health Perspect 2012;120:1010–16.
49 U.S. Environmental Protection Agency. Respiratory health effects of passive
smoking: lung cancer and other disorders. Washington D.C: US Environmental
Protection Agency, Office of Health and Environmental Assessment, Office of
Research and Development, 1992.
50 Jaakkola MS, Jaakkola JJ. Assessment of exposure to environmental tobacco smoke.
Eur Respir J 1997;10:2384–97.
51 Klepeis NE, Gabel EB, Ott WR, et al. Outdoor air pollution in close proximity to a
continuous point source. Atmos Environ 2009;43:3155–67.
52 St. Helen G, Hall DB, Kudon LH, et al. Particulate matter (PM2.5) and carbon
monoxide from secondhand smoke outside bars and restaurants in downtown
Athens, Georgia. J Environ Health 2011;74:8–17.
53 World Health Organization. WHO air quality guidelines for particulate matter,
ozone, nitrogen dioxide and sulfur dioxide: Summary of risk assessment. Global
Update 2005. http://whqlibdoc.who.int/hq/2006/WHO_SDE_PHE_OEH_06.02_eng.
pdf (accessed 31 Jan 2012).
54 U.S. Environmental Protection Agency. Particulate Matter: PM Standards—Table:
National Ambient Air Quality Standards for Particle Pollution. http://www.epa.gov/
pm/standards.html (accessed 20 May 2011).
55 New South Wales Government: Office of Environment & Heritage. National
Environment Protection Measure for Ambient Air Quality: Air Monitoring Plan for
NSW- Summary, June, 2001. http://www.environment.nsw.gov.au/air/nepm/
summary.htm (accessed 13 May 2011).
56 U.S. Environmental Protection Agency. AIR NOW: Air Quality Index (AQI)—A guide
to air quality and your health. http://airnow.gov/index.cfm?action=aqibasics.aqi.
(accessed 12 May 2011).
57 Klepeis NE, Ott WR, Switzer P. A multiple-smoker model for predicting indoor air
quality in public lounges. Environ Sci Technol 1996;30:2813–20.
58 Pope CA 3rd, Dockery DW. Health effects of fine particulate air pollution: lines that
connect. J Air Waste Manage Assoc 2006;56:709–42.
59 World Health Organization—International Agency for Research on Cancer.
Involuntary Smoking: Composition, Exposure, and Regulations. In: IARC
Monographs on the Evaluation of Carcinogenic Risks to Humans: Tobacco Smoking
and Involuntary Smoking. Volume 83, 2004. Lyon, France.
60 Baker RR, Proctor CJ. The origins and properties of environmental tobacco smoke.
Environ Internatl 1990;16:231–45.
8 Licht AS, et al.Tob Control 2012;0:1–8. doi:10.1136/tobaccocontrol-2012-050493
Review
group.bmj.com on December 5, 2012 - Published by tobaccocontrol.bmj.comDownloaded from
doi: 10.1136/tobaccocontrol-2012-050493
published online December 5, 2012Tob Control
Andrea S Licht, Andrew Hyland, Mark J Travers, et al.
literaturequantitative review of the research andoutdoor hospitality venues: a qualitative
Secondhand smoke exposure levels in
http://tobaccocontrol.bmj.com/content/early/2012/12/04/tobaccocontrol-2012-050493.full.html
Updated information and services can be found at:
These include:
Data Supplement http://tobaccocontrol.bmj.com/content/suppl/2012/12/04/tobaccocontrol-2012-050493.DC1.html
"Supplementary Data"
References f-list-1
http://tobaccocontrol.bmj.com/content/early/2012/12/04/tobaccocontrol-2012-050493.full.html#re
This article cites 38 articles, 12 of which can be accessed free at:
P<P Published online December 5, 2012 in advance of the print journal.
service
Email alerting the box at the top right corner of the online article.
Receive free email alerts when new articles cite this article. Sign up in
Notes
(DOIs) and date of initial publication.
publication. Citations to Advance online articles must include the digital object identifier
citable and establish publication priority; they are indexed by PubMed from initial
typeset, but have not not yet appeared in the paper journal. Advance online articles are
Advance online articles have been peer reviewed, accepted for publication, edited and
http://group.bmj.com/group/rights-licensing/permissions
To request permissions go to:
http://journals.bmj.com/cgi/reprintform
To order reprints go to:
http://group.bmj.com/subscribe/
To subscribe to BMJ go to:
group.bmj.com on December 5, 2012 - Published by tobaccocontrol.bmj.comDownloaded from