United States	Office of	June 1989
Environmental Protection	Air and Radiation
Agency	(ANR-445)
oEPA Indoor Air Facts No. 5
Environmental
Tobacco Smoke
Environmental Tobacco Smoke (ETS) is one of the
most widespread and harmful indoor air pollutants.
ETS comes from secondhand smoke exhaled by
smokers and sidestream smoke emitted from the
burning end of cigarettes, cigars, and pipes. ETS is
a mixture of irritating gases and carcinogenic tar
particles. It is a known cause of lung cancer and
respiratory symptoms, and has been linked to heart
disease. Breathing in ETS is also known as "involun-
tary" or "passive" smoking.
What's The Big Deal About A Little Smoke?
In the United States, 50 million smokers annually
smoke approximately 600 billion cigarettes, 4 billion
cigars, and the equivalent of 11 billion pipesful of
tobacco. Since people spend approximately 90
percent of their time indoors, this means that about
467,000 tons of tobacco are burned indoors each
year. Over a 16-hour day, the average smoker
smokes about two cigarettes per hour, and takes
about ten minutes per cigarette. Thus, it takes only
a few smokers in a given space to release a more-or-
less steady stream of ETS into the indoor air.
In 1985, three major bodies were independently
convened to consider the public health implications
of passive smoking. Commissioned by the U.S.
Public Health Service under the Surgeon General, by
the National Research Council (NRC) at the request
of EPA, and by the congressionally-mandated
Interagency Task Force on Environmental Cancer,
Heart, and Lung Disease, the three bodies arrived at
a consensus: passive smoking significantly increases
the risk of lung cancer in adults. In the words of the
Surgeon General, "a substantial number of the lung
cancer deaths that occur among nonsmokers can be
attributed to involuntary smoking." Moreover, there
was agreement that passive smoking substantially
increases respiratory illness in children and the NRC
recommended eliminating ETS from the environ-
ments of small children.
Why ETS Is Harmful
Because the organic material in tobacco doesn't burn
completely, cigarette smoke contains more than 4,700
chemical compounds, including: carbon monoxide,
nicotine, carcinogenic tars, sulfur dioxide, ammonia,
nitrogen oxides, vinyl chloride, hydrogen cyanide,
formaldehyde, radionuclides, benzene, and arsenic.
These chemicals have been shown in animal studies
to be highly toxic. Many are treated as hazardous
when emitted into outdoor air by toxic-waste dumps
and chemical plants.
There are 43 carcinogenic compounds in tobacco
smoke. In addition, some substances are mutagenic,
which means they can cause permanent, often
harmful, changes in the genetic material of cells.
EPA research has shown that EPS is the major
source of mutagens indoors when smoking occurs.
Higher levels of mutagenic particles arc found in
homes with ETS than in homes with wood stoves or
in outdoor urban environments with numerous diesel
trucks and buses.
Many studies have shown that nonsmokers absorb
ETS components in their body fluids. The effect of
ETS on nonsmokers depends on the duration of
exposure. According to the National Research
Council, short-term visitors to a smoking area arc
most likely to be annoyed by the tobacco smoke
odors, whereas nonsmoking occupants of the area
are more likely to complain about irritating effects
to the eyes, nose or throat. Long-term exposure to
ETS may lead to more serious health effects.
Impact On Children
Passive smoking induces serious respiratory symp-
toms in children. Wheezing, coughing and sputum
production among children of smoking parents
increase by 20 percent to 80 percent depending on
the symptom being assessed and the number of
smokers in the household. Asthmatic children arc
particularly at risk.
Printed on Recycled Paper

-------
Children of smokers have significantly higher
rates of hospitalization for bronchitis and pneu-
monia, and a number of studies report that chronic
ear infections are more common in young children
whose parents smoke. Also lung development is
slower in children exposed to ETS. Lung problems
caused by ETS exposure in childhood can extend into
adult life.
ETS And Cancer
The U.S. Surgeon General and the NRC agree that
ETS can cause cancer. The NRC estimates that the
risk of lung cancer is roughly 30 percent higher for
nonsmoking spouses of smokers than for nonsmoking
spouses of nonsmokers. In 1986, an estimated 23,000
U.S. nonsmokers died from lung cancer, and the
Surgeon General attributes a substantial number of
those deaths to passive smoking.
ETS And Heart Disease
The Interagency Task Force on Environmental
Cancer, Heart, and Lung Disease Workshop on ETS
concluded that the effects of ETS on the heart may
be of even greater concern than its cancer-causing
effects on the lungs. ETS aggravates the condition
of people with heart disease, and several studies have
linked involuntary smoking with heart disease.
ETS's Contribution To Indoor Air Pollution
There arc many potential sources of indoor air
pollution, including chemicals emanating from
building materials, furnishings, and consumer pro-
ducts; gases from combustion appliances like space
heaters and furnaces; and biological contaminants
from a variety of sources. Because cigarettes, pipes,
and cigars produce clouds of tar particles when
smoked, ETS is a major contributor of particulate
indoor air pollution. ETS also contributes numerous
toxic gases to indoor air, including carbon monoxide,
formaldehyde and ammonia.
Field studies, controlled experiments, and mathe-
matical models show that, under typical conditions of
smoking and ventilation, ETS diffuses rapidly
throughout buildings and homes, persists for long
periods after smoking ends, and represents one of
the strongest sources of indoor-air particulate pol-
lution in buildings where smoking is permitted.
Studies of indoor air quality in commercial and
public buildings show that particulate levels in areas
where smoking is permitted arc considerably higher
than in nonsmoking areas. Studies using personal air
monitors have shown that a single smoker in a home
can double the amount of particulate air pollution
inhaled by nonsmoking members of the household.
Evidence Of Nonsmoker Exposure
Nicotine, a chemical unique to tobacco, has been
found to be a widespread air contaminant in build-
ings where smoking occurs. Nicotine breaks down
into cotinine as it passes through the body. Cotinine
can be detected and measured in the saliva, blood,
and urine of nonsmokers, indicating they have
absorbed tobacco smoke from the air. Concentra-
tions of cotinine have been found in the body fluids
of infants of smoking parents, and of adults who
were unaware they had been exposed to ETS.
Removal Of ETS From Indoor Air
Environmental tobacco smoke can be totally removed
from the indoor air only by removing the source
(cigarette smoking). Separating smokers and non-
smokers in the same room may reduce, but will not
eliminate, nonsmokers' exposure to tobacco smoke.
Placing smokers and non-smokers in sepaiate rooms
that are on the same ventilation system also may
reduce nonsmokers' exposure to tobacco smoke; this
approach, however, will probably not eliminate
exposure to tobacco smoke since most pollutants
readily disperse through a common air space and
since, in public or commercial buildings, most
H VAC systems recirculate much of the contaminated
indoor air.
In 1981, the American Society of I leating, Refri-
gerating, and Air-Conditioning Engineers
(ASHRAE), in its standard "Ventilation for Accept-
able Indoor Air Quality" recommended five cubic
feet of outside air per minute per occupant
(cfm/occ) in smoke-free office buildings and 20
cfm/occ in buildings where smoking is permitted.
These recommendations were not designed to reduce
health risks (for example, limiting cancer incidence
or eye irritation); rather, the recommendations were
intended to control the odor from tobacco smoke so
that 80 percent of visitors (smokers and nonsmokers
combined) to the building find it acceptable. A
proposed revision of this standard recommends a
minimum of 15 cfm/occ in all buildings.
Research indicates that total removal of tobacco
smoke through ventilation is both technically and
economically impractical. The effectiveness of air
filters for removing ETS particles from the indoor
air is generally dependent on the type and efficiency
of the air cleaner used; the effectiveness of air
cleaners in removing the gaseous components of
2

-------
tobacco smoke and other air pollutants requires
further research.
Since there is no established, health-based thres-
hold for exposure to environmental tobacco smoke
and since EPA generally does not recognize a no-
effect or safe level for cancer causing agents, the
Agency recommends that exposure to environmental
tobacco smoke be minimized wherever possible. The
most effective way to minimize exposure is to
restrict smoking to smoking areas that arc separately
ventilated and directly exhausted to the outside, or
by eliminating smoking in the building entirely.
The Public Reaction To ETS
People are becoming increasingly sensitized to the
issue of ETS. Numerous surveys have documented
that the majority of both smokers and nonsmokers
support restrictions on smoking in publ ic, particular-
ly in the workplace. In a 1987 Gallup National
Opinion Survey, 55 percent of all persons inter-
viewed (including smokers and nonsmokers) were in
favor of a total ban on all smoking in public places.
As a result, thousands of businesses and hundreds
of cities, as well as over 40 states and the District of
Columbia restrict smoking in various settings. The
number continues to grow rapidly.
Conclusion
EPA shares the recommendations of the 1986 Sur-
geon General's Report:
o Adults should protect the health of children by
not exposing them to environmental tobacco
smoke.
o Employers and employees should ensure that the
act of smoking does not expose nonsmokers to
environmental tobacco smoke by restricting
smoking to separately ventilated areas or banning
smoking from buildings.
o Smokers should ensure that their behavior docs
not jeopardize the health of others.
o Nonsmokers should support smokers who are
trying to quit.
For More Information
Eor additional information on environmental tobacco
smoke, contact your state or local health depart-
ments, nonprofit agencies such as your local Lung
Association, Cancer Society or I leart Association, or
the following:
Office on Smoking and Health
U.S. Public Health Service
5600 Eishers Lane, Room I-10
Rockvillc, MD 20857
Public Relations Office
American Society of Heating
Refrigerating and Air Conditioning
Engineers (ASHRAE)
1791 i'ullic Circle, NE.
Atlanta, GA 30329
Office of Cancer Communications
National Cancer Institute
I -800-4-CANCER
Smoking Policy Institute
914 East Jefferson
Suite 219
P.O. Mox 20271
Seattle, WA 98102
Americans for Nonsmokers' Rights
2054 University Avenue
Suite 500
Berkeley, CA 94704
Action on Smoking and Health
2013 11 Street, NW.
Washington, DC 20006
Cigarette smoke is only one of many indoor air
pollutants that can affect your health and comfort.
Other EPA publications concerning the quality of
indoor air include:
o The Inside Slory: A Guide to Indoor Air Quality
o Directory of State Indoor Air Contacts
o Indoor Air Pacts >'1: EPA and Indoor Air Quality
o Indoor Air Facts »2: EPA Indoor Air Quality
Implementation Plan
o Indoor Air Facts "3: Ventilation and Air Quality
in Offices
o Indoor Ait "Facts "4. Sick Buildings
These publications, as well as additional copies of
this fact sheet, arc available from:
Public Information Center
U.S. Environmental Protection Agency
Mail Code PM-21113
401 M Street, SW.
Washington, DC 20460
3

-------