Secondhand Tobacco Smoke in Public Places
Ana Navas-Acien, MD, PhD, MPH
Johns Hopkins Bloomberg School of Public Health
 2007 Johns Hopkins Bloomberg School of Public Health
Section A
Smoke-Free Environments
 2007 Johns Hopkins Bloomberg School of Public Health
Learning Objectives
Discuss the main direct and indirect benefits of smoke-free
environments
View creating smoke-free environments as a key strategy for
tobacco control worldwide
Describe policy relevant methods to track exposure to secondhand
tobacco smoke in public places and to evaluate smoke-free policies
Provide country and state examples with complete smoke-free
policies in public places
 2007 Johns Hopkins Bloomberg School of Public Health
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WHO Framework Convention on Tobacco Control
Article 8: Protection from Exposure to Tobacco Smoke
 “Parties recognize that scientific evidence has unequivocally
established that exposure to tobacco smoke causes death,
disease, and disability”
 “Each party shall adapt and implement, in areas of existing
rational jurisdiction as determined by national law, and
actively promote at other jurisdictional levels the adoption
and implementation of effective, legislative, administrative,
and/or other measures providing for protection from exposure
to tobacco smoke in indoor workplaces; public transport,
indoor public places and, as appropriate, other public places”
Source: World Health Organization. (2005).
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Why Are Smoke-Free Environments Important?
Smoke-free environments prevent death and disease
Direct health benefits
 Protect nonsmokers from the health consequences of
involuntary exposure to tobacco smoke
 Less people exposed to tobacco smoke  less disease
Indirect health benefits
 Motivate smokers to quit and reduce tobacco consumption
 Reduce the number of people initiating smoking
 Less people smoke  less disease
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Evidence Supporting Smoke-Free Workplaces
Systematic review of 26 studies found that
smoke-free workplaces were associated
with:
 Reduction in smoking prevalence =
3.8% (95% CI*: 2.8%, 4.7%)
 Reduction in cigarettes/day among
smokers = 3.1 (95% CI*: 2.4, 3.8)
 Limitation: cross-sectional evidence
*CI: confidence interval
Source: Fichtenberg and Glantz. (2002).
 2007 Johns Hopkins Bloomberg School of Public Health
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Evidence Supporting Smoke-Free Workplaces
Impact of Worksite Smoking Policies (Three Levels) on Quitting and Amount Smoked
Quitting
Amount smoked
Worksite smoking policy
(1993–2001)
No. of
respondents
Quit,
Raw %
OR
(95% CI)
Unadjusted
mean CPD†
No. of
respondents
 weight
(95% CI)
Level 1: maintained or
changed to smoking
allowed everywhere
93
20.1
Reference
21.8
88
Reference
Level 2: maintained or
changed to smoking in
designated areas
335
27.4
1.73
(0.96, 3.11)
19.8
262
–0.82
(–0.96, 1.21)
Level 3: maintained or
changed to smoking
prohibited
1,391
30.5
1.92*
(1.11, 3.32)
16.9
1,038
–2.57
(–4.40, –0.59)*
*P < .05; †CPD = cigarettes per day
Source: Bauer, et al. (2005).
 2007 Johns Hopkins Bloomberg School of Public Health
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Positive Health Impact of Smoke-Free Environments
Source: Navas, A. (2007).
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Impact on Cardiovascular Health
Source: adapted by CTLT from Bartecchi, et al. (2006).
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Impact on Respiratory Health
Symptoms and Spirometry Before and After Introduction of the Smoking Ban (N=77)
Before Ban
1 Month
After Ban
Change from
Baseline (95% CI)
P
Value
Any
79.2 (61)
53.2 (41)
–26 (–13.8 to –38.1)
<.001
Respiratory
62.3 (48)
41.5 (32)
–20.8 (–7.6 to –33.9)
.005
Sensory
71.4 (55)
40.3 (31)
–31.2 (–18.1 to –44.3)
<.001
No. of symptoms, median (IQR)
2 (1 to 4)
1 (0 to 3)
–1 (–2 to 0)
.001
Entire cohort
96.6 (2.26)
104.8 (2.53)
8.2 (3.9 to 12.4)
<.001
Otherwise healthy
98.7 (2.52)
104.4 (2.94)
5.7 (1.0 to 10.3)
.04
Asthma
90.3 (4.86)
106.1 (5.06)
15.7 (5.7 to 25.7)
.008
Symptoms, % (No.)
FEV1, mean (SE), %
CI=confidence interval; FEV1=forced expiratory volume in the first second; IQR=interquartile range
Source: Menzies, et al. (2006).
 2007 Johns Hopkins Bloomberg School of Public Health
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Other Reasons to Support Smoke-Free Environments
Large public support for smoke-free legislations
Support increases when legislation passes
 In Ireland, support for a total ban in workplaces increased
from 40% before the ban to 65% after the smoking ban*
No economic damage to business
 Best designed studies report no impact or a positive impact of
smoke-free legislations in bars and restaurants on sales or
employment†
Strong opposition of tobacco industry
Source: *Fong, et al. (2006); †Scollo, et al. (2003).
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Challenge to Smoke-Free Policies: Industry Tactics
Industry promotes ineffective
policies
 Accommodation
 Ventilation
Influence on legislation
Negation or minimization of
health effects
“If smoking were banned in
all workplaces, the industry’s
average consumption would
decline… and the quitting
rate would increase… Clearly,
it is most important for PM to
continue to support
accommodation for smokers
in the workplace.”
- Philip Morris, 1992
Image source: adapted by CTLT from Tobacco Atlas 2nd Edition. (2006); Text source: Ramsey S. (2002).
 2007 Johns Hopkins Bloomberg School of Public Health
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Challenge to Smoke-Free Policies: Industry Tactics
“According to PAHO, the report reveals that
tobacco companies hired scientists throughout
Latin America and the Caribbean to
misrepresent the science linking second-hand
smoke to serious diseases, while cloaking in
secrecy any connection of these scientists
with the tobacco industry”
—S. Ramsey, 2002
 2007 Johns Hopkins Bloomberg School of Public Health
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Reasons Why Smoke-Free Environments Are Important
Protect nonsmokers
Help smokers to quit and to reduce
consumption
Denormalization of tobacco use to reduce
initiation of tobacco by youth
Large support for smoking bans by population
No economic damage to business
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