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Secondhand Smoke Exposure Levels in Outdoor Hospitality Venues: A Qualitative and Quantitative Review of the Research Literature


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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 (PM2.5) depends on the number of smokers present, measurement proximity, outdoor enclosures, and wind. Annual excess PM2.5 exposure of full-time waitstaff at outdoor smoking environments could average 4.0 to 12.2 μg/m3 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.
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,
Andrew Hyland,
Mark J Travers,
Simon Chapman
Additional data are
published online only. To view
these les please visit the
journal online (http://dx.doi.
Department of Social and
Preventive Medicine, State
University of New York at
Buffalo, Buffalo, New York,
Department of Health
Behavior, Roswell Park Cancer
Institute, Buffalo, New York,
School of Public Health,
University of Sydney, Sydney,
Correspondence to
Andrea Licht, Department
of Health Behavior, Roswell
Park Cancer Institute, Elm and
Carlton Streets, Buffalo, NY
14263, USA; andrea.licht@
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
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
) depends on the number of smokers present,
measurement proximity, outdoor enclosures, and wind.
Annual excess PM
exposure of full-time waitstaff at
outdoor smoking environments could average 4.0 to
12.2 μg/m
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
Secondhand smoke (SHS) is a rich source of sus-
pended ne particulates and is a signicant con-
tributor to total particulate load in indoor
environments where smoking occurs.
An elevation
of 10 mg/m
of long-term exposure to ne particle
air pollution (particulate matter (PM)
), including
that from tobacco smoke, is associated with 6%,
9% and 14% increased risk for all cause, cardiopul-
monary and lung cancer mortality respectively.
Indoor smoke-free air laws have had lasting and
important health benets including improved
indoor air quality, reductions in SHS exposure and
tobacco use, and lower rates of respiratory and car-
diovascular events.
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.
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
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
Globally, outdoor smoking restrictions are
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.
Given the limited
research linking exposures to SHS from outdoor
environments to health effects, many current pol-
icies have been justied 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.
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.
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.
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.
Regardless, acute health effects have been asso-
ciated with short-term, low level SHS exposure.
Even very low concentrations (4.4 μg/m
) of envir-
onmental tobacco smoke (measured in PM
were found to facilitate eye, nasal and throat irrita-
tions among non-smokers.
Potentially more
serious acute effects on respiratory
and cardiovas-
cular health have been observed, such as impaired
ow-mediated vasodilation in healthy non-
endothelial cell morbidity,
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-
cic conditions, SHS levels can be temporarily
comparable with or even temporarily higher than
levels observed indoors.
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;0:18. doi:10.1136/tobaccocontrol-2012-050493 1
TC Online First, published on December 5, 2012 as 10.1136/tobaccocontrol-2012-050493
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venues, and to estimate the levels of SHS exposure that may be
experienced by wait staff working at typical outdoor hospitality
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.
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,
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 eld and searches of personal research collections. The 7
studies found in the grey literature are only considered as sup-
plementary evidence.
19 33 38 3942
Using the data obtained from the experimental and observa-
tional studies in the peer-reviewed literature, estimates of excess
exposure were calculated. These estimates are meant to
approximate the above-background PM
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.
Measuring SHS contamination in outdoor settings
Given the complex nature of SHS, direct measurements are dif-
cult 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
and the individual biological dose received,
though cotinine, a nicotine metabolite.
However, airborne
nicotine concentrations may not necessarily reect that of other
constituents of SHS,
and between-individualdifferences in
nicotine metabolism have been noted.
44 45
Other studies have
measured specic carcinogenic components of SHS, such as par-
ticulate polycyclic aromatic hydrocarbons (PPAH)
or the
tobacco-specic carcinogen 4-(methylnitrosamino)-1-(3-
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 dif-
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
) are not spe-
cic 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
levels (see online supplementary
appendix A). The remainder of this paper focuses on SHS expo-
sures measured by PM
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 quantied 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 monitors native unit to measure respirable
suspended particle (RSP) mass concentrations in μg/m
which is
a close approximation of PM
Monitor clusters were placed
on opposite sides of smolder-smoked cigarettes at distances
between 0.25 and 4 m away. Smokingsessions used 35 cigar-
ettes burned successively. During periods of active smokingthe
overall average OTS particle levels ranged from 1022 mg/m
(NEPH) to 3861 mg/m
(PAS) across all distances over 10 min
experimental periods. These results were likely inuenced by a
microplume effect, in which highly transitory peaks, some
exceeding 1000 mg/m
, 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.
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 70110 mg/m
, calcu-
lated using the reported average ne particulate emission rate of
cigarettes (1.4 mg/min), the normalised average single direction
concentration of 5080 mg/m
per mg/min (from CO experi-
ments), and a range of horizontal distances of 0.250.5 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 inuence SHS
) exposures in outdoor hospitality venues. In particular,
four observational studies in the peer reviewed literature pro-
vided the most detailed information on such factors.
2830 52
Three of these studies collected PM
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.
2 Licht AS, et al.Tob Control 2012;0:18. doi:10.1136/tobaccocontrol-2012-050493
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fourth study measured real-time PM
levels using the DustTrak
(TSI, Incorporated: Shoreview, Minnesota, USA) monitor, also
applying a calibration factor of 0.32 to the raw data.
Cameron et al collected data within 1 m of active smokers at a
convenience sample of 69 outdoor dining areas in Melbourne,
Mean ambient levels were 8 mg/m
averaged 18 mg/m
across the total observation time period
(average of 25.8 min/venue) and 27 mg/m
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
of particulates over the entire measurement period.
Stafford et al
measured PM
levels in 28 alfresco cafes and
pubs in Perth and Mandurah, Australia. Mean PM
levels for
none, one and two or more smokers were 3.98, 10.59 and
17.00 mg/m
, respectively, with the weighted average PM
centration over smoking presentperiods being 14 mg/m
(total of
388 smoking min logged). After adjusting for background levels
(3.98 mg/m
), active smoking outdoors contributed a 10 mg/m
boost in PM
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.
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
levels decreased 38% after implementation of the
smoking ban (from 19.0 mg/m
to 13.1 mg/m
), while adjusting
for ambient PM
levels (5 mg/m
). 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
signicantly increase at the post-ban assessment.
A study by St. Helen and colleagues from the U.S. observed
outdoor PM
levels at vehospitalityvenuesmeasuredonupto
four separate occasions. Mean PM
levels at three locations (Bar 1:
63.9 mg/m
, Bar 2: 51.0 mg/m
, and Restaurant 1: 39.7 mg/m
foundtobesignicantly elevated above ambient levels (20.4 mg/m
p<0.0001). After adjusting for vehicular trafc near venues, the
number of smokers present remained the only statistically signicant
predictor of Log(PM
) levels, indicating that SHS exposures are the
likely source of PM
levels observed at outdoor areas of hospitality
venues. However, this study did not adjust for other factors that are
known to inuence PM
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.
Other observational studies have come to similar conclusions,
but the ndings should be interpreted cautiously. Compared
with other studies,
2830 52
outdoor PM
levels were observed
to be much higher in studies by Wilson and colleagues.
four randomly selected outdoor smoking areas of hospitality
venues, an average of four lit cigarette present produced mean
levels of 36 mg/m
(range 1975) while ambient concen-
trations averaged 14 mg/m
. In two purposefully selected
outdoor areas with a higher degree of enclosure, mean PM
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 outdoorspace
can dramatically increase PM
There is also evidence to suggest that OTS can drift indoors,
compromising indoor smoke-free environments.
67283235 39
addition, once tobacco smoke has drifted indoors, it does not
dissipate as quickly as it would in outdoor environments.
However, most of these studies did not specify the distance
from entrances to monitors or other factors such as trafc
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 ndings are obtained from these
studies: (1) observational studies estimate that exposure to SHS
outdoors adds approximately 10 mg/m
or more of excess PM
exposure; (2) although exposures are almost always highly tran-
sitory, experimental studies nd 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
concentration can be
similar to levels observed in indoor smoking allowable areas,
but these levels are highly inuenced by external factors.
Inuence of external factors on levels of exposure to SHS
Number of lit cigarettes
Resu lts from Zhang, et al showed that increasing numbers of lit
cigarettes per 1000 ft
of patio area (0, 1.04.3, 4.48.7, 8.816.7
and 16.841.7 lit cigarettes) increased the GM PPAH levels from
4.7 mg/m
(no cigarettes) to 9.1, 16.9, 19.1 and 27.0 mg/m
Although regression models by Stafford et al only
predicted about 40% of the overall variance in PM
, the number
of active smokers present was found to be the greatest contributor
to the variance.
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
adjusting for pedestrian and vehicle trafc, St. Helen and collea-
gues found that lit cigarettes at or passing by outdoor study sites
signicantly increased log (PM
) levels.
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
27 51
but approached ambient levels at distances >2 m.
Based on regression modelling by Cameron, cigarettes smoked
at distances >1 m from a monitor did not signicantly predict
overall PM
levels (p=0.261).
Outdoor SHS levels have
been found to be roughly equal to or greater than indoor SHS
levels at very close distances (<0.5 m).
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;0:18. doi:10.1136/tobaccocontrol-2012-050493 3
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RSP levels were approximately three times higher downwind
relative to upwind levels.
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
levels of 130 mg/m
measured at 0.6 m away. Mean RSP levels
were still elevated above background levels by 1341 mg/m
further downwind distances away (1.72.7 m), while RSP levels
measured at 0.6 m upwind to smolder-smoked cigarettes were
nearly zero (2 mg/m
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 0.20.5 m/s.
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 3050% higher concen-
trations downwind nearby active smoking.
Partial enclosures
Enclosures such as walls, fences, garden umbrellas and roofs can
substantially inuence exposures to SHS in outdoor areas. These
conditions may lead to street canyoneffects 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.
The purposeful monitoring of two highly
enclosed outdoorsmoking areas in New Zealand demonstrated
the inuence of SHS exposures under these conditions; mean
levels were found to be 124 mg/m
compared with only 36 mg/
from open air smoking areas.
Although Brennan and col-
leagues found no association between outdoor air quality and
the level of enclosure,
two studies estimate that outdoor over-
head coverage can increase SHS levels by about 5070%.
27 29
From unpublished literature, mean PM
levels in outdoor
hospitality venues in Vancouver, BC ranged from 6 to 430 μg/
, although many of these venues had complete roof coverings
and nearly complete wall coverings.
High, yet transitory peak
10-s PM
level were also found in a fairly enclosed outdoor
courtyard (716 μg/m
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.
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 Australias
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
but some studies have attempted to estimate 24-h or annual
exposure from outdoor SHS using the aforementioned
or the US Air Quality Index.
30 41 56
standards were devised for total ambient air pollution which has
a different composition than tobacco-specic pollution.
However, the fundamental issue is whether such transient
outdoor SHS exposures are sufcient 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
levels are elevated by approximately 10 mg/m
during times when active smoking occurs.
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
exposure would be exceeded based on these
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 reect real-world exposures. Nevertheless, work
by Klepeis et al
estimated that the EPA 24-h standard for ne
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
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
exposures would likely be exceeded only if extra-
occupational PM
exposures are assumed.
Table 1 Maximum ambient particulate concentration standards from Australia (Air NEPM), the USA (NAAQS), and the WHO
Pollutant Averaging period WHO (mg/m
) USA (mg/m
) Australia (mg/m
particles 24 h 50 150 50
particles 24 h 25 35 25
1 year 10 15 8
Source (AU):
Source (US):
Source (WHO):
NAAQS, National Ambient Air Quality Standards; PM, particulate matter.
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Estimated projections combining observational and experimental
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%
and 70%
their total working time, or about the SHS equivalent of 0.40.7
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).
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
online supplementary appendix B).
This gure can be manipu-
lated to resemble OTS pollution using exposure data on the
presence of active smoking from observational studies
29 30
the ne particle emission rate for a cigarette (1.4 mg/min).
From this data, the excess PM
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
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
levels averaged from observational studies (6. 5 mg/m
), the excess
occupational OTS attributable PM
exposure for an 8-h shift was
calculated to be 17.5 mg/m
under the lower smoking exposure
condition, 35.4 mg/m
under the moderate smoking exposure con-
dition, and 53.4 mg/m
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
(lower exposure)
and 8.9 mg/m
(higher exposure) of excess 24-hour PM
exposure attributable to outdoor occupational SHS. Among full
time workers (8-hour shifts), this would equate to between
5.8 mg/m
and 17.8 mg/m
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
(part time) to 12.2 mg/m
(full time) of added PM
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
Although it may be plausible that such exposures could occa-
sionally exceed the annual PM
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
data are averaged across a large
distance from the emission source (0.254m) to reect 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.
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 briey exposed to high concentrations of tobacco-
generated PM
under certain conditions. Evidence from the
studies presented here suggests that these levels may occasionally
Table 2 Estimates of 24-hour and Annual PM
exposures (in μg/m
) 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 times0.4
lit cigarettes
lit cigarettes
lit cigarettes
lit cigarettes
lit cigarette
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/
0.56 mg/
0.98 mg/
0.98 mg/
1.4 mg/
1.4 mg/
Average air pollution concentration across all distances
and angles§
42.8 μg/m
42.8 μg/m
42.8 μg/m
42.8 μg/m
42.8 μg/m
42.8 μg/m
Average exposure for 8-hr Shift* 24.0 μg/m
24.0 μg/m
41.9 μg/m
41.9 μg/m
59.9 μg/m
59.9 μg/m
Assumed ambient air concentration (constant)¶ 6.5 μg/m
6.5 μg/m
6.5 μg/m
6.5 μg/m
6.5 μg/m
6.5 μg/m
Excess exposure above ambient air concentration* 17.5 μg/m
17.5 μg/m
35.4 μg/m
35.4 μg/m
53.4 μg/m
53.4 μg/m
24-h excess PM
Exposure from occupational OTS* 2.9 μg/m
5.8 μg/m
5.9 μg/m
11.8 μg/m
8.9 μg/m
17.8 μg/m
Annual excess PM
exposure from occupational OTS* 2.0 μg/m
4.0 μg/m
4.0 μg/m
8.1 μg/m
6.1 μg/m
12.2 μg/m
*See appendix B, uploaded as Web Onlymaterial, for an explanation of all calculations.
From Cameron et al
: active smoking was present 38.4% of the total observation time; From Stafford et al
, 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
first reported the average fine particulate emission rate for cigarettes of 1.4 mg/min.
§Klepeis et al
this figure (42.8 μg/m
) was calculated from table 3 using light wind (0.1 m/s) speeds
¶Ambient levels averaged 6.5 μg/m
across observational studies, which were usually measured at off-site locations where no smoking was observed to occur. Brennan: 5 μg/m
Cameron: 8 μg/m
, Perry: 6 μg/m
, Stafford: 4 μg/m
, Wilson et al
, and Wilson et al
PM, particulate matter.
Licht AS, et al.Tob Control 2012;0:18. doi:10.1136/tobaccocontrol-2012-050493 5
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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
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.
Popeandcolleaguesestimatethatanincreaseof510 mg/m
average annual PM
exposure is associated with a 36%
increased risk in all-cause mortality.
Similarly, increases in annual
exposures are also associated with increased risk of cardio-
pulmonary and lung cancer mortality.
As our calculated annual
estimates of excess PM
exposures attributable to OTS ranged
from 2.012.2 mg/m
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 connes 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, difculty 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
Additional studies were found that assessed PM
exposures in
non-hospitality settings such as outside of buildings, walking on
city streets or in semi-enclosed bus shelters.
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 rst 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
Therefore, it is plausible that PM
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 inuence SHS levels
outdoors. Another limitation is that these ndings are based on
measurements that have been obtained from a wide range of
outdoorareas 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
, 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 Pollutiondid
not result in the identication of additional studies of interest.
Thus, the search criteria used was likely sufcient 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
exposures from SHS alone in outdoor
smoking-allowable hospitality settings to exceed the aforemen-
tioned PM
guidelines. Although these estimates do not
incorporate non-tobacco PM
sources due to limitations of
the available data, SHS related PM
exposures from these
outdoor hospitality settings may be signicant contributors to
overall 24-h or annual PM
Policy-driven smoke-free policies have typically been
grounded in the prevention of adverse health effects to
non-users of tobacco products.
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 benets 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;0:18. doi:10.1136/tobaccocontrol-2012-050493
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What this paper adds
This paper is one of the rst to review the evidence related to
secondhand smoke (SHS) exposure in outdoor areas of
hospitality venues. The ndings 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
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 nal manuscript. All authors reviewed
and accepted the nal 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 ofcial
views of the National Cancer Institute or the National Institutes of Health.
Competing interests None.
Provenance and peer review Not commissioned; externally peer reviewed.
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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
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... The outdoor SHS levels reported in this study were considerably higher than those found in households with residential smokers that allowed smoking inside (Arechavala et al., 2018). Other research further characterizing SHS exposure at outdoor hospitality settings also demonstrated that SHS concentrations can be high and increase with the degree of enclosure, smoker density, and the number of active cigarettes (Stafford et al., 2010;Licht et al., 2013;Fu et al., 2016;Sureda et al., 2013Sureda et al., , 2018. Furthermore, biomarkers of SHS exposure (i.e. ...
... However, while current restrictions rely on the premise that there are low SHS levels in outdoor spaces (Kennedy et al., 2010) available evidence shows SHS exposure outdoors can substantially increase with just the presence of overhead covers (Cameron et al., 2010;Licht et al., 2013;Fu et al., 2016). Besides, there are other issues with these types of partial bans. ...
... Sites with overhead covers and a minimum of three sidewalls had more than twice the median concentrations than less enclosed venues. Earlier studies assessing SHS exposure with airborne markers have reported similar results (Cameron et al., 2010;Stafford et al., 2010;Licht et al., 2013;Fu et al., 2016;Sureda et al., 2018). ...
Objective Due to partial or poorly enforced restrictions secondhand tobacco smoke (SHS) is still present in outdoor hospitality venues in many European countries. This study aimed to assess SHS concentrations in outdoor hospitality venues across Europe and identify contextual exposure determinants. Methods Cross-sectional study. We measured airborne nicotine and evidence of tobacco use in terraces of bars, cafeterias, and pubs from 11 European countries in 2017-2018. Sites were selected considering area-level socioeconomic indicators and half were visited during nighttime. We noted the smell of smoke, presence of smokers, cigarette butts, ashtrays, and number of physical covers. Contextual determinants included national smoke-free policies for the hospitality sector, the Tobacco Control Scale score (2016), and the national smoking prevalence (2017-2018). We computed medians and interquartile ranges (IQR) of nicotine concentrations and used multivariate analyses to characterize the exposure determinants. Results Nicotine was present in 93.6% of the 220 sites explored. Overall concentrations were 0.85 (IQR:0.30-3.74) μg/m³ and increased during nighttime (1.45 IQR:0.65-4.79 μg/m³), in enclosed venues (2.97 IQR:0.80-5.80 μg/m³), in venues with more than two smokers (2.79 IQR:1.03-6.30 μg/m³), in venues in countries with total indoor smoking bans (1.20 IQR:0.47-4.85 μg/m³), and in venues in countries with higher smoking prevalence (1.32 IQR:0.49-5.34 μg/m³). In multivariate analyses, nicotine concentrations were also positively associated with the observed number of cigarette butts. In venues with more than two smokers, SHS levels did not significantly vary with the venues’ degree of enclosure. Conclusions Our results suggest that current restrictions in outdoor hospitality venues across Europe have a limited protective effect and justify the adoption of total smoking bans in outdoor areas of hospitality venues.
... Addressing secondhand smoke exposure in outdoor environments is important because the U.S. Surgeon General has concluded that there is no risk-free level of secondhand smoke exposure, 22 and levels of secondhand smoke exposure in certain outdoor settings may be the same or at times even higher than those observed in indoor settings where smoking has occurred in close proximity. 23 The current study findings, in addition to the prior research, suggest the importance of 100% smoke-free policies in indoor areas of workplaces, including the expansion of such policies to include restrictions to prevent employees and others from involuntary exposure to secondhand smoke in outdoor settings. 1,3,23,24 The extent of 100% smoke-free policy coverage varied by occupation. ...
... 23 The current study findings, in addition to the prior research, suggest the importance of 100% smoke-free policies in indoor areas of workplaces, including the expansion of such policies to include restrictions to prevent employees and others from involuntary exposure to secondhand smoke in outdoor settings. 1,3,23,24 The extent of 100% smoke-free policy coverage varied by occupation. Direct comparisons with previous research were not possible due to variation in occupation groupings and changes in the occupation codes and selected occupation classification groups. ...
... Previous studies have indicated that the prevalence of combustible tobacco smoking and exposure to secondhand smoke among workers in the construction and mining industry workers is high, 23−27 and that the implementation of smoke-free policies can eliminate or substantially decrease exposure to secondhand smoke in workplaces. 4,9,23,24,27 Therefore, tailored efforts to identify barriers to quitting, creating 100% smoke-free environments, and integrating tobacco cessation programs with health promotion activities could help reduce combustible tobacco smoking and existing smoking disparities, particularly among industries with the greatest burden of tobacco usage. 3,[18][19][20]28 Tobacco dependence treatment is one of the most cost-effective preventive services and has been shown to provide substantial return on investment in the short and long term because of the enormous costs of smoking on society and employers, including direct healthcare costs and lost productivity. ...
Full-text available
Introduction: Workplace tobacco control interventions reduce smoking and secondhand smoke exposure among U.S. workers. Data on smoke-free workplace policy coverage and cessation programs by industry and occupation are limited. This study assessed smoke-free workplace policies and employer-offered cessation programs among U.S. workers, by industry and occupation. Methods: Data from the 2014-2015 Tobacco Use Supplement to the Current Population Survey, a random sample of the civilian, non-institutionalized population, were analyzed in 2018. Self-reported smoke-free policy coverage and employer-offered cessation programs were assessed among working adults aged ≥18 years, overall and by occupation and industry. Respondents were considered to have a 100% smoke-free policy if they indicated smoking was not permitted in any indoor areas of their workplace, and to have a cessation program if their employer offered any stop-smoking program within the past year. Results: Overall, 80.3% of indoor workers reported having smoke-free policies at their workplace and 27.2% had cessation programs. Smoke-free policy coverage was highest among workers in the education services (90.6%) industry and lowest among workers in agriculture, forestry, fishing, and hunting industry (64.1%). Employer-offered cessation programs were significantly higher among workers reporting 100% smoke-free workplace policies (30.9%) than those with partial/no policies (23.3%) and were significantly higher among indoor workers (29.2%) than outdoor workers (15.0%). Conclusions: Among U.S. workers, 100% smoke-free policy and cessation program coverage varies by industry and occupation. Lower smoke-free policy coverage and higher tobacco use in certain industry and occupation groups suggests opportunities for workplace tobacco control interventions to reduce tobacco use and secondhand smoke exposure.
... The amount of smoke that reaches a person exposed to cigarette smoke is affected by the size of the area, the amount of air change in the environment, and the distance from the source of the smoke (24). In an experimental study, Licht et al. (25) reported that the amount of respirable suspended particles increased as the distance between the smoking location and the monitor used for measurement decreased. Hence, it is not surprising that the associated side effects worsen as exposure increases. ...
... benefits of these policies in children. 42,[64][65][66][67][68] We did not identify any study exploring the differential effects of novel smoke-free policies in low-income countries. This consideration is worthy of future investigation because previous studies have observed that population-level tobacco control policies could produce greater health benefits in low-income populations than in high-income populations. ...
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Background Smoke-free policies in outdoor areas and semi-private and private places (eg, cars) might reduce the health harms caused by tobacco smoke exposure (TSE). We aimed to investigate the effect of smoke-free policies covering outdoor areas or semi-private and private places on TSE and respiratory health in children, to inform policy. Methods In this systematic review and meta-analysis, we searched 13 electronic databases from date of inception to Jan 29, 2021, for published studies that assessed the effects of smoke-free policies in outdoor areas or semi-private or private places on TSE, respiratory health outcomes, or both, in children. Non-randomised and randomised trials, interrupted time series, and controlled before–after studies, without restrictions to the observational period, publication date, or language, were eligible for the main analysis. Two reviewers independently extracted data, including adjusted test statistics from each study using a prespecified form, and assessed risk of bias for effect estimates from each study using the Risk of Bias in Non-Randomised Studies of Interventions tool. Primary outcomes were TSE in places covered by the policy, unplanned hospital attendance for wheezing or asthma, and unplanned hospital attendance for respiratory tract infections, in children younger than 17 years. Random-effects meta-analyses were done when at least two studies evaluated policies that regulated smoking in similar places and reported on the same outcome. This study is registered with PROSPERO, CRD42020190563. Findings We identified 5745 records and assessed 204 full-text articles for eligibility, of which 11 studies met the inclusion criteria and were included in the qualitative synthesis. Of these studies, seven fit prespecified robustness criteria as recommended by the Cochrane Effective Practice and Organization of Care group, assessing smoke-free cars (n=5), schools (n=1), and a comprehensive policy covering multiple areas (n=1). Risk of bias was low in three studies, moderate in three, and critical in one. In the meta-analysis of ten effect estimates from four studies, smoke-free car policies were associated with an immediate TSE reduction in cars (risk ratio 0·69, 95% CI 0·55–0·87; 161 466 participants); heterogeneity was substantial (I² 80·7%; p<0·0001). One additional study reported a gradual TSE decrease in cars annually. Individual studies found TSE reductions on school grounds, following a smoke-free school policy, and in hospital attendances for respiratory tract infection, following a comprehensive smoke-free policy. Interpretation Smoke-free car policies are associated with reductions in reported child TSE in cars, which could translate into respiratory health benefits. Few additional studies assessed the effect of policies regulating smoking in outdoor areas and semi-private and private places on children’s TSE or health outcomes. On the basis of these findings, governments should consider including private cars in comprehensive smoke-free policies to protect child health.
... Since January 2003 the Italian Government declared a national ban for cigarette smoking in indoor public places and workplaces, but nowadays some health concerns are arising from outdoor secondhand smoke (SHS) exposure for non-smokers, particularly near the public place entrances such as restaurants, bars, facilities of big industrial factories and hospital venues. Several studies in literature confirm the contribution of SHS to the outdoor environmental pollution and to poor air quality [1][2][3][4][5][6][7][8][9][10][11]. ...
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Background: Indoor smoking in public places and workplaces is forbidden in Italy since 2003, but some health concerns are arising from outdoor secondhand smoke (SHS) exposure for non-smokers. One of the biggest Italian Steel Manufacturer, with several factories in Italy and abroad, the Marcegaglia Group, recently introduced the outdoor smoking ban within the perimeter of all their factories. In order to encourage their smoker employees to quit, the Marcegaglia management decided to set up an educational framework by measuring the PM1, PM2.5 and PM10 emissions from heavy duty trucks and to compare them with the emissions of cigarettes in an indoor controlled environment under the same conditions. Methods: The exhaust pipe of two trucks powered by a diesel engine of about 13.000/14.000 cc3 were connected with a flexible hose to a hole in the window of a container of 36 m3 volume used as field office. The trucks operated idling for 8 min and then, after adequate office ventilation, a smoker smoked a cigarette. Particulate matter emission was thereafter analyzed. Results: Cigarette pollution was much higher than the heavy duty truck one. Mean of the two tests was: PM1 truck 125.0(47.0), cigarettes 231.7(90.9) p = 0.002; PM2.5 truck 250.8(98.7), cigarettes 591.8(306.1) p = 0.006; PM10 truck 255.8(52.4), cigarettes 624.0(321.6) p = 0.002. Conclusions: Our findings may be important for policies that aim reducing outdoor SHS exposure. They may also help smokers to quit tobacco dependence by giving them an educational perspective that rebuts the common alibi that traffic pollution is more dangerous than cigarettes pollution.
Secondhand smoke (SHS) remains a common health threat in densely populated, urban settings. We estimated the prevalence of exposure and associated respiratory symptoms, knowledge, attitudes, and behaviors in a multi‐ethnic, weighted sample of Singapore residents using a cross‐sectional survey of 1806 adults. We weighted data to match the national population in terms of gender, ethnicity, and education level and analyzed data using descriptive statistics, bivariate analyses, multiple linear and logistic regressions, and a multinomial logistic regression model. About 88% of respondents reported regular SHS exposure. Nearly 57% reported exposure to neighbors' SHS at home. Respiratory symptoms were reported by 32.5% and significantly associated with exposure to daily (AOR = 2.63, 95% CI = 1.62–4.36), non‐daily (AOR = 1.75, 95% CI = 1.14–2.77), and neighbors' (AOR = 1.37, 95% CI = 1.07–1.76) SHS. More knowledge of SHS was associated with male gender (β = 0.28, p = 0.0009) and higher household income (linear trend; p = 0.0400). More negative attitudes to SHS were associated with older age (linear trend; p < 0.0001). Engaging in behaviors to avoid SHS was associated with a more negative attitude to SHS (AOR = 1.09–1.23). SHS exposure is common in Singapore's densely populated setting and associated with respiratory symptoms, even if exposure is non‐daily or from neighboring homes.
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Passive smoke contains more than 7,000 chemicals, including hundreds that are toxic and about 70 that can cause cancer. This is because the smoke that burns off the end of a cigar or cigarette contains more harmful substances (tar, carbon monoxide, nicotine, among others) than the smoke inhaled by the smoker. The study investigated the determinants knowledge, perception and exposure risk to passive smoking among in-school Adolescents in Ibadan Southeast Local Government Area, Nigeria. The study adopted a cross-sectional survey design. Multi stage sampling techniques were used to select four hundred and ten participants (414) among in-school Adolescents in Ibadan Southeast Local Government Area, Nigeria. The instrument was a self-report questionnaire to collect data in the study and was subjected to validation. Obtained data was analyzed using descriptive statistics of frequency and percentages. Also, correlation analyses were used to test the hypothesis at 95% confidence level (α=0.05). Three research questions and two research hypotheses were tested in the study. The results showed that the mean age was 17.05±1.39 years. The result revealed that the majority of the participants 337(82.2%) had poor knowledge about passive smoking, while 73(17.8%) of the respondents had good knowledge about passive smoking. Also, the result revealed that the majority of the participants 165(40.2%) reported low exposure risk of passive smoking. Correlation analyses show that there is a significant relationship between adolescents’ knowledge and exposure risk to passive smoking among in-school adolescents in Ibadan southeast local government area (r=0.22; p=0.000). There is also a significant relationship between perception and exposure risk to passive smoking among in-school adolescents in Ibadan south east local government area (r=0.13; p=0.009). The study therefore concluded and recommended that training programmers’ should be provided to increase the adolescents’ awareness, change their perceptions, increase their ability to protect themselves and help to have a smoke-free environment.
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Introduction Smoke-free enclosed public environments are effective in reducing exposure to secondhand smoke and yield major public health benefits. Building on this, many countries are now implementing smoke-free policies regulating smoking beyond enclosed public places and workplaces. In order to successfully implement such ‘novel smoke-free policies’, public support is essential. We aim to provide the first comprehensive systematic review and meta-analysis assessing levels and determinants of public support for novel smoke-free policies. Methods and analysis The primary objective of this review is to summarise the level of public support for novel smoke-free policies. Eight online databases (, Medline ALL Ovid, Web of Science Core Collection, WHO Library Database, Latin American and Caribbean Health Sciences Literature, Scientific Online Library Online, PsychINFO and Google Scholar) will be searched from 1 January 2004 by two independent researchers with no language restrictions. The initial search was performed on 15 April 2020 and will be updated prior to finalisation of the report. Studies are eligible if assessing support for novel smoke-free policies in the general population (age ≥16 years) and have a sample size of n≥400. Studies funded by the tobacco industry or evaluating support among groups with vested interest are excluded. The primary outcome is proportion of public support for smoke-free policies, subdivided according to the spaces covered: (1) indoor private spaces (eg, cars) (2) indoor semiprivate spaces (eg, multi-unit housing) (3) outdoor (semi)private spaces (eg, courtyards) (4) non-hospitality outdoor public spaces (eg, parks, hospital grounds, playgrounds) and (5) hospitality outdoor public spaces (eg, restaurant terraces). The secondary objective is to identify determinants associated with public support on three levels: (1) within-study determinants (eg, smoking status) (2) between-study determinants (eg, survey year) and (3) context-specific determinants (eg, social norms). Risk of bias will be assessed using the Mixed Methods Appraisal Tool and a sensitivity analysis will be performed excluding studies at high risk of bias. Ethics and dissemination No formal ethical approval is required. Findings will be disseminated to academics, policymakers and the general public.
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In 2007 Minnesota passed into law a comprehensive ban on indoor smoking of tobacco products in public places including bars, restaurants, and workplaces. Despite reductions in smoking prevalence in the past 12 years, people are still exposed to secondhand smoke (SHS). It remains important to understand where and how long nonsmokers face exposure to SHS. The 2018 Minnesota Adult Tobacco Survey was analyzed to examine self-reported SHS exposure among nonsmoking adults. We report prevalence and 95 percent confidence intervals of SHS exposure overall, by specific locations, and by demographics. Length of exposure to SHS was summarized in median minutes. Overall, 30 percent of nonsmokers reported exposure in the past seven days. A total of 1382 participants indicated a location of exposure. The most common locations other than one’s own home or car included building entrances (18.7 [16.2-21.1] percent), somewhere else outdoors (17.7 [15.1-20.3] percent), and restaurant/bar patios (12.8 [10.5-15.0] percent). Exposure was more likely to be reported by young adults (44.6 percent) and males (33.7 percent). The locations with the longest duration of SHS exposure in the prior seven days were a gambling venue (117.2 [72.2-162.2] minutes), another person’s home (26.1 [15.4-36.8] minutes), and a bus stop (10.8 [4.7-16.9] minutes). Monitoring nonsmokers’ self-reported exposure to SHS remains important as a way to measure the impact and compliance with smoke-free policies. Additional information on the location and duration of exposure can be used programmatically to address high levels of exposure and consider additional policies or strategies.
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Introduction: Youth exposure to secondhand smoke (SHS) and secondhand aerosol from e-cigarettes (SHA) may contribute to the renormalization of tobacco product use behaviors. Our study assessed self-reported SHS or SHA exposures in indoor or outdoor public places among US students. Methods: Data came from the 2015 and 2017 National Youth Tobacco Survey, a school-based survey of US students in grades 6 through 12. Past 30-day exposure to SHS and SHA in indoor and outdoor public places was assessed. The prevalence of exposure was assessed overall and by covariates for each year. We used adjusted prevalence ratios (aPRs) to assess determinants of exposure. Results: We observed no significant change from 2015 through 2017 in exposure to SHS (52.6% to 50.5%), SHA (25.2% to 25.6%), or either SHS or SHA (56.7% to 55.1%). Following multivariable adjustment, in 2017, exposure to either SHS or SHA in public was higher among female students versus male students (aPR = 1.29), high school students versus middle school students (aPR = 1.15), current e-cigarette users versus nonusers (aPR = 2.89), and current users of other tobacco product versus nonusers (aPR = 1.21). Exposure was higher for students who reported that a household member used tobacco products. Conclusion: In 2017, more than half (55.1%, 14.3 million) of US middle and high school students reported exposure to secondhand tobacco product emissions in indoor or outdoor public places. E-cigarette use may complicate the enforcement of existing smoke-free policies and contribute to the renormalization of tobacco use behaviors. Continued efforts are warranted to reduce the social acceptability of tobacco product use and protect bystanders from all tobacco product emissions.
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Efforts to understand and mitigate the health effects of particulate matter (PM) air pollution have a rich and interesting history. This review focuses on six substantial lines of research that have been pursued since 1997 that have helped elucidate our understanding about the effects of PM on human health. There has been substantial progress in the evaluation of PM health effects at different timescales of exposure and in the exploration of the shape of the concentration-response function. There has also been emerging evidence of PM-related cardiovascular health effects and growing knowledge regarding interconnected general pathophysiological pathways that link PM exposure with cardiopulmonary morbidity and mortality. Despite important gaps in scientific knowledge and continued reasons for some skepticism, a comprehensive evaluation of the research findings provides persuasive evidence that exposure to fine particulate air pollution has adverse effects on cardiopulmonary health. Although much of this research has been motivated by environmental public health policy, these results have important scientific, medical, and public health implications that are broader than debates over legally mandated air quality standards.
• Blood was obtained before and after ten healthy male nonsmokers sat for 20 minutes in open hospital corridors beside men who were already there smoking by their own initiative. Mean values before and after passive smoking were 0.87 and 0.78 for the platelet aggregate ratio, 2.8 and 3.7 per counting chamber for the endothelial cell count, 0 and 2.8 ng/mL for the plasma nicotine concentration, and 0.9% and 1.3% for the carboxyhemoglobin level. No variable changed significantly during control periods in which the subjects sat in a room where smoking was prohibited. Passive exposure to tobacco smoke affected the endothelial cell count and platelet aggregate ratio in a manner similar to that previously observed with active smoking.(Arch Intern Med 1989;149:386-389)
Platelet activating effect of cigarette smoking appears to be important in the development of atherosclerosis. We previously demonstrated a reduced sensitivity of platelets to exogenous prostacyclin (PGI2) in vitro from patients with proven atherosclerotic disease, indicating a possible role of altered platelet function in the development of atherosclerosis. We now hypothesize that cigarette smoking might be an important cause of altered platelet sensitivity to PGI2 observed in patients with atherosclerosis. To test this hypothesis, the response of platelets to exogenous PGI2 was tested in chronic smokers and non-smokers, prior to and after smoking two cigarettes (active smoking) and prior to and after exposure to a tobacco smoke-contaminated atmosphere (passive smoking). This study indicates that platelets of chronic smokers are less sensitive to exogenous PGI2 than platelets of non-smokers. In addition, active as well as passive smoking decreases platelet sensitivity to PGI2 in non-smokers, whereas chronic smokers exhibit no further decline. We conclude that decreased platelet sensitivity to PGI2 might be an important contributing factor to the altered platelet function observed in patients with atherosclerosis.
This research evaluates commuter exposure to particulate matter during pre-journey commute segments for passengers waiting at bus stops by investigating 840 min of simultaneous exposure levels, both inside and outside seven bus shelters in Buffalo, New York. A multivariate regression model is used to estimate the relation between exposure to particulate matter (PM2.5 measured in μg m−3) and three vectors of determinants: time and location, physical setting and placement, and environmental factors. Four determinants have a statistically significant effect on particulate matter: time of day, passengers’ waiting location, land use near the bus shelter, and the presence of cigarette smoking at the bus shelter. Model results suggest that exposure to PM2.5 inside a bus shelter is 2.63 μg m−3 (or 18 percent) higher than exposure outside a bus shelter, perhaps due in part to the presence of cigarette smoking. Morning exposure levels are 6.51 μg m−3 (or 52 percent) higher than afternoon levels. Placement of bus stops can affect exposure to particulate matter for those waiting inside and outside of shelters: air samples at bus shelters located in building canyons have higher particulate matter than bus shelters located near open space.
Data are lacking on human exposure to air pollutants occurring in ground-level outdoor environments within a few meters of point sources. To better understand outdoor exposure to tobacco smoke from cigarettes or cigars, and exposure to other types of outdoor point sources, we performed more than 100 controlled outdoor monitoring experiments on a backyard residential patio in which we released pure carbon monoxide (CO) as a tracer gas for continuous time periods lasting 0.5–2h. The CO was emitted from a single outlet at a fixed per-experiment rate of 120–400ccmin−1 (∼140–450mgmin−1). We measured CO concentrations every 15s at up to 36 points around the source along orthogonal axes. The CO sensors were positioned at standing or sitting breathing heights of 2–5ft (up to 1.5ft above and below the source) and at horizontal distances of 0.25–2m. We simultaneously measured real-time air speed, wind direction, relative humidity, and temperature at single points on the patio. The ground-level air speeds on the patio were similar to those we measured during a survey of 26 outdoor patio locations in 5 nearby towns. The CO data exhibited a well-defined proximity effect similar to the indoor proximity effect reported in the literature. Average concentrations were approximately inversely proportional to distance. Average CO levels were approximately proportional to source strength, supporting generalization of our results to different source strengths. For example, we predict a cigarette smoker would cause average fine particle levels of approximately 70–110μgm−3 at horizontal distances of 0.25–0.5m. We also found that average CO concentrations rose significantly as average air speed decreased. We fit a multiplicative regression model to the empirical data that predicts outdoor concentrations as a function of source emission rate, source–receptor distance, air speed and wind direction. The model described the data reasonably well, accounting for ∼50% of the log-CO variability in 5-min CO concentrations.
A mathematical multiple-smoker model for predicting the minute-by-minute indoor time series and time-averaged pollutant concentrations from environmental tobacco smoke (ETS) was developed and tested during 10 visits to glass-enclosed public smoking lounges at two international airports in the San Francisco Bay Area. The model is based on the mass balance equation and uses counts of active smokers as input. Its predictions were compared with the time series measurements of carbon monoxide (CO) and respirable suspended particles (RSP). The experimental time series for RSP was determined by averaging the readings (2-min averages) from moni tors at three widely-spaced locations in the lounge. At 8 out of the 10 visits, instantaneous CO concentrations also were measured every 2−3 min from a single monitor at the center of the room. The average emission rates per cigarette for CO and RSP for two visits in which the air exchange rates were measured were found to be 11.9 and 1.43 mg/min, respectively, which are consistent with values reported elsewhere in the literature. There was excellent agreement (0−12% error) between the observed RSP and CO concentration time series average and average concentrations predicted by the model for all study visits. Regression results between observed and predicted time series were also excellent. The average difference between the time-averaged RSP concentrations measured at the three widely spaced locations in the room and the average concentration across the room was about 12%. These results suggest that the model can be used by human exposure assessors and smoking lounge designers to predict the average exposures that people will experience for visits of typical duration.