What Is Secondhand Smoke?
In January 2006, the California Air Resources
Board added secondhand tobacco smoke to its list
of “toxic air contaminants.” The Board based its
decision on scientific studies that link secondhand
smoke to heart disease, asthma, other respiratory
diseases, and cancer among nonsmokers.
Secondhand smoke is also known as
environmental tobacco smoke (ETS), passive
smoke, or involuntary smoke. It is released into
the air when tobacco products burn or when
smokers exhale. Cigarettes, cigars, and pipes all
can produce toxic secondhand smoke.
This pamphlet summarizes some of the findings
from a recent comprehensive review of hundreds
of studies of secondhand smoke by the California
EPA’s Office of Environmental Health Hazard
Is Secondhand Smoke
This smoke is a mixture of gases and fine particles
containing more than 4,000 chemicals. Many of
these can cause harmful health effects. For
example, secondhand smoke contains over 50
chemicals known to cause cancer, such as
benzene, chromium, and formaldehyde. Other
toxic chemicals in secondhand smoke include
cyanide and carbon monoxide.
Children may be exposed to secondhand smoke
in homes and daycare, at outdoor smoking areas,
in cars, and anywhere that people are smoking.
Office of Environmental Health Hazard AssessmentCalifornia Environmental Protection Agency1001 I StreetSacramento, CA 95814Office of Environmental Health Hazard Assessment
California Environmental Protection Agency
Is Secondhand Smoke More Harmful
Yes. Children are more likely than adults to suffer
health effects from secondhand smoke because:
• Children breathe in more air than adults for
their size and weight.
• Children’s bodies continue to grow and
develop as they get older and taller. During
this time of growth, they can be more
sensitive to the effects of secondhand smoke.
It is especially dangerous to their developing
lungs and immune systems.
The lungs continue to de