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One
Page Summary
National
Report on Human Exposure to Environmental Chemicals
Tobacco /
Smoking
Background
Tobacco use is the leading preventable
cause of death in the United States, resulting in 400,000 deaths per year
from disease such as lung cancer, heart disease, and emphysema. Exposure
to environmental tobacco smoke causes an additional 3,000 deaths from lung
cancer each year. Approximately 25% of adults in the U.S. smoke, and
approximately 35% of high school students have used some form of tobacco
in the past month.
Current Research at DLS
The Air Toxicants Laboratory,
DLS, and NCEH
perform research and surveillance
investigating how chemical additives, constituents, and design affect the
toxicity, carcinogenicity, and addictiveness of tobacco use. This
information is intended to further the scientific understanding of how
chemical makeup and product design influence the health consequences of
tobacco products, aiding public health officials in evaluating the
effectiveness of tobacco-control measures.
The Air Toxicants Laboratory is
the only laboratory of its kind established:
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To characterize and evaluate the chemical constituents and chemical additives
of tobacco products.
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To characterize
the chemical and physical properties of tobacco products that influence
delivery of nicotine and other harmful substances.
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To identify the
causative agents of disease in tobacco and tobacco smoke, especially
second-hand smoke.
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To assess
exposure of the U.S. population (particularly children, women of childbearing
age, and other susceptible groups) to the harmful chemical constituents of
tobacco smoke.
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To collaborate
in health studies examining the relation of secondhand smoke exposure
to cancer, asthma, sudden infant death syndrome, birth defects and other
diseases and conditions.
Selected Research Findings
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Cotinine in human serum: CDC
developed a sensitive and specific method to measure cotinine, a
breakdown product of nicotine, in human serum. The method uses 50
microliters to 1 milliliter of serum. The method analyzes
100 samples per day and can detect cotinine levels as low as 50 ng/L.
This enables assessment of nonsmokers’ exposure to environmental
tobacco smoke.
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Exposure of the U.S. population to
environmental tobacco smoke: Using a nationally representative
sample of the U.S. population from the Third National Health and
Nutrition Examination Survey (NHANES III), CDC assessed the population’s
exposure to environmental tobacco smoke. The study included
self-reported exposure and measurements of cotinine levels in people’s
serum. The study found that 87.9% of nonsmokers had detectable levels
of serum cotinine. People reporting higher numbers of smokers in
the household and more hours of tobacco smoke at work had
significantly higher serum cotinine levels. In addition, children,
non-Hispanic blacks, and males had higher levels of serum cotinine
levels, indicating higher exposure to environmental tobacco smoke.
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Flavor-related compounds in
cigarette tobacco: CDC developed a method to quantify 12
flavor-related compounds in cigarette tobacco. Genotoxicity or
carcinogenicity has been reported for several of these compounds. In
tests of 68 brands of cigarettes, 62% contained one or more of the 12
compounds. The most frequently detected compounds were anethole,
myristicin, and safrole.
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Tobacco-specific nitrosamines in
cigarettes: CDC developed a method to measure four tobacco-specific
nitrosamines (TSNAs) in tobacco products. NNK and NNN, two of TSNAs
measured, have been found to be potent carcinogens in animal tests.
These carcinogens are found only in tobacco. Wide variation in TSNA
levels was observed among ten cigarette brands likely due to
differences in tobacco blending practices used by the different
manufacturers.
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Nicotine, pH, and moisture levels
of snuff products: In partnership with Florida, CDC assessed the nicotine, pH, and moisture content of six
moist snuff products. These products reflected a cross-section of the
products from the five leading U.S. moist snuff brands sold in the
U.S. during 1997. The analysis found substantial differences in the
pH, the amount of moisture and nicotine, and the percentage of free
nicotine in these brands. Free nicotine levels ranged from a mean
value of 0.23% to 68.14%. Free nicotine is the chemical form most
readily absorbed into the bloodstream.
Important Links to Learn More About
Tobacco
CDC
Office on Smoking and Health
Food and
Drug Administration
Federal Trade Commission (FTC)
FTC
Report of tar, nicotine, CO levels
World Health Organization
Health Canada
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