Tobacco smoke
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Tobacco smoke is a
Composition
The particles in tobacco smoke are liquid aerosol droplets (about 20% water), with a mass median aerodynamic diameter (MMAD) that is submicrometer (and thus, fairly "lung-respirable" by humans). The droplets are present in high concentrations (some estimates are as high as 1010 droplets per cm3).
Tobacco smoke may be grouped into a particulate phase (trapped on a glass-fiber pad, and termed "TPM" (total particulate matter)) and a gas/vapor phase (which passes through such a glass-fiber pad). "Tar" is mathematically determined by subtracting the weight of the nicotine and water from the TPM. However, several components of tobacco smoke (e.g., hydrogen cyanide, formaldehyde, phenanthrene, and pyrene) do not fit neatly into this rather arbitrary classification, because they are distributed among the solid, liquid and gaseous phases.[1]
Tobacco smoke contains a number of toxicologically significant chemicals and groups of chemicals, including polycyclic aromatic hydrocarbons (benzopyrene), tobacco-specific nitrosamines (NNK, NNN), aldehydes (acrolein, formaldehyde), carbon monoxide, hydrogen cyanide, nitrogen oxides (nitrogen dioxide), benzene, toluene, phenols (phenol, cresol), aromatic amines (nicotine, ABP (4-aminobiphenyl)), and harmala alkaloids. The radioactive element polonium-210 is also known to occur in tobacco smoke.[1] The chemical composition of smoke depends on puff frequency, intensity, volume, and duration at different stages of cigarette consumption.[3]
Between 1933 and the late 1940s, the yields from an average cigarette varied from 33 to 49 mg "tar" and from less than 1 to 3 mg nicotine. In the 1960s and 1970s, the average yield from cigarettes in Western Europe and the USA was around 16 mg tar and 1.5 mg nicotine per cigarette. Current average levels are lower.
Tobacco
Tumorigenic agents
Compounds | In processed tobacco, per gram | In mainstream smoke, per cigarette | IARC evaluation of evidence of carcinogenicity | |
---|---|---|---|---|
In laboratory animals | In humans | |||
Polycyclic aromatic hydrocarbons | ||||
Benz(a)anthracene | 20–70 ng | sufficient | ||
Benzo(b)fluoranthene
|
4–22 ng | sufficient | ||
Benzo(j)fluoranthene | 6–21 ng | sufficient | ||
Benzo(k)fluoranthene | 6–12 ng | sufficient | ||
Benzo(a)pyrene | 0.1–90 ng | 20–40 ng | sufficient | probable |
Chrysene | 40–60 ng | sufficient | ||
Dibenz(a,h)anthracene | 4 ng | sufficient | ||
Dibenzo(a,i)pyrene
|
1.7–3.2 ng | sufficient | ||
Dibenzo(a,l)pyrene
|
present | sufficient | ||
Indeno(1,2,3-c,d)pyrene | 4–20 ng | sufficient | ||
5-Methylchrysene | 0.6 ng | sufficient | ||
Aza-arenes
| ||||
Quinoline | 1–2 μg | |||
Dibenz(a,h)acridine | 0.1 ng | sufficient | ||
Dibenz(a,j)acridine | 3–10 ng | sufficient | ||
7H-Dibenzo(c,g)carbazole | 0.7 ng | sufficient | ||
N-Nitrosamines | ||||
N-Nitrosodimethylamine | 0–215 ng | 0.1–180 ng | sufficient | |
N-Nitrosoethylmethylamine | 3–13 ng | sufficient | ||
N-Nitrosodiethylamine | 0–25 ng | sufficient | ||
N-Nitrosonornicotine | 0.3–89 μg | 0.12–3.7 μg | sufficient | |
4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone | 0.2–7 μg | 0.08–0.77 μg | sufficient | |
N-Nitrosoanabasine | 0.01–1.9 μg | 0.14–4.6 μg | limited | |
N-Nitrosomorpholine | 0–690 ng | sufficient | ||
Aromatic amines | ||||
2-Toluidine
|
30–200 ng | sufficient | inadequate | |
2-Naphthylamine | 1–22 ng | sufficient | sufficient | |
4-Aminobiphenyl | 2–5 ng | sufficient | sufficient | |
Aldehydes | ||||
Formaldehyde | 1.6–7.4 μg | 70–100 μg | sufficient | |
Acetaldehyde | 1.4–7.4 μg | 18–1400 μg | sufficient | |
Crotonaldehyde | 0.2–2.4 μg | 10–20 μg | ||
Miscellaneous organic compounds | ||||
Benzene | 12–48 μg | sufficient | sufficient | |
Acrylonitrile | 3.2–15 μg | sufficient | limited | |
1,1-Dimethylhydrazine
|
60–147 μg | sufficient | ||
2-Nitropropane | 0.73–1.21 μg | sufficient | ||
Ethyl carbamate | 310–375 ng | 20–38 ng | sufficient | |
Vinyl chloride | 1–16 ng | sufficient | sufficient | |
Inorganic compounds | ||||
Hydrazine | 14–51 ng | 24–43 ng | sufficient | inadequate |
Arsenic | 500–900 ng | 40–120 ng | inadequate | sufficient |
Nickel | 2000–6000 ng | 0–600 ng | sufficient | limited |
Chromium | 1000–2000 ng | 4–70 ng | sufficient | sufficient |
Cadmium | 1300–1600 ng | 41–62 ng | sufficient | limited |
Lead | 8–10 μg | 35–85 ng | sufficient | inadequate |
Polonium-210 | 0.2–1.2 pCi | 0.03–1.0 pCi | sufficient | sufficient |
Safety
Tobacco smoke, besides being an
In spite of all changes in cigarette design and manufacturing since the 1960s, the use of filters and "light" cigarettes has neither decreased the nicotine intake per cigarette, nor has it lowered the incidence of lung cancers (
In the United States, lung cancer incidence and mortality rates are particularly high among African American men. Lung cancer tends to be most common in developed countries, particularly in North America and Europe, and less common in developing countries, particularly in Africa and South America.[8][clarification needed]
See also
- Liquid smoke
- Electronic cigarette aerosol
- Tobacco smoke enema
References
- ^ ISBN 978-0-12-745354-5
- ^ Ken Podraza (29–30 October 2001), Basic Principles of Cigarette Design and Function (PDF), Philip Morris USA
- ^ a b The Health Consequences of Smoking: The Changing Cigarette (PDF), U.S. Dept. of Health and Human Services, p. 49
- Environmental Health Criteria, World Health Organization
- ^ Michael A. H. Russell (1977), "Smoking Problems: An Overview", in Murray E. Jarvik; Joseph W. Cullen; Ellen R. Gritz; Thomas M. Vogt; Louis Jolyon West (eds.), Research on Smoking Behavior (PDF), NIDA Research Monograph, pp. 13–34, archived from the original (PDF) on 2015-07-23
- ISBN 978-3527306732
- ISBN 978-0-12-745354-5
- ^ ISBN 978-1-4160-4710-0
- ISBN 978-1-4160-4710-0