What is in a cigarette?

We often hear that there are over 4,000 chemicals in a cigarette. More precisely more than 4,000 chemicals have been identified in cigarette smoke. These chemicals are the product of combustion of the cigarette, and there are a number of articles about them and how they cause harm (cut and paste the links at the bottom).




But what is actually in a cigarette…before it is lit?
The cigarette itself typically contains a large number of ingredients, including the tobacco leaf, tobacco paper, ink used to write on and color the filter and paper, the filter itself (fibers of which may be inhaled)—, and over 500 potential additives (e.g.,acetaldehyde, ammonia, cocoa, levulinic acid, and menthol). Some of the chemicals are added as part of the agricultural process required to grow a healthy tobacco plant (insecticides, fertilizers, metals absorbed from the soil etc), some chemicals become attached to the tobacco leaf during post-harvesting processes (e.g. curing) and then some chemicals are intentionally added with the intent of altering the chemical effects or taste of the smoked product (e.g. menthol).
One of the best articles I’ve read on the subject of cigarette additives was written by Clive bates, Professor Martin Jarvis, and Professor Greg Connolly on behalf of UK ASH (Action of Smoking and Health). The article link is provided below, but here are some of the summary findings:
“Additives are used to make cigarettes that provide high levels of 'free' nicotine which increases the addictive 'kick' of the nicotine. Ammonium compounds can fulfil this role by raising the alkalinity of smoke
Additives are used to enhance the taste of tobacco smoke, to make the product more desirable to consumers. Although seemingly innocuous the addition of flavourings making the cigarette 'attractive' and 'palatable' is in itself cause for concern.
Sweeteners and chocolate may help to make cigarettes more palatable to children and first time users; eugenol and menthol numb the throat so the smoker cannot feel the smoke's aggravating effects.
Additives such as cocoa may be used to dilate the airways allowing the smoke an easier and deeper passage into the lungs exposing the body to more nicotine and higher levels of tar.
Some additives are toxic or addictive in their own right or in combination. When additives are burned, new products of combustion are formed and these may be toxic or pharmacologically active.
Additives are used to mask the smell and visibility of side-stream smoke, making it harder for people to protect themselves and undermining claims that smoking is anti-social without at the same time reducing the health risks of passive smoking.”

As I have discussed in previous posts, we used to think that some of these additives, like menthol for example, were simply intended to provide a distinctive taste. Now, however, we are starting to see more evidence suggesting that simple additives like menthol can influence the way the cigarette is smoked and hence its addictiveness and harmfulness.
But although there is evidence that certain ingredients in tobacco may make it more harmful, we also need to be clear that even tobacco with no additives is lethal and addictive when lit and smoked.

Tobacco Additives: Cigarette engineering and addiction.
http://old.ash.org.uk/html/regulation/html/additives.html

What is in cigarette smoke? 2/17/08
http://www.healthline.com/blogs/smoking_cessation/2008/02/what-is-in-cigarette-smoke.html

Carbon-monoxide in cigarette smoke. 8/0208
http://www.healthline.com/blogs/smoking_cessation/2008/08/carbon-monoxide-in-cigarette-smoke.html

http://health.howstuffworks.com/smoking-starve-the-heart-of-oxygen.htm/printable

Labels: additives, chemicals, jonathan foulds, tobacco

Permalink and Comments | | Email Post

What is in cigarette smoke?

More than 4000 different chemicals have been identified in cigarette smoke. Most of us have a very basic idea that these chemicals can be harmful to health and that the mechanisms whereby this complex mixture of toxins contained in tobacco smoke leads to specific diseases are complex. However, I thought it might be helpful to some readers to provide a very basic description of the ways in which some of these components of cigarette smoke cause ill-health.

The simplest categorization of the components if cigarette smoking identifies 3 major components: tar, nicotine, and cabon-monoxide (CO).

Tar is the black sticky mass that coats the lungs and the airways. There are many hundreds of different chemicals within the tar, some of which have been shown to be carcinogenic in animals and/or humans. The deposition of particles of tar in the lungs and upper airways leads to the blocking of airways and to serious breathing problems, including Chronic Obstructive Pulmonary Disease (COPD). The toxic chemicals also cause inflammation and reduce the elasticity of the lungs and hence the ability to inhale and exhale normally.

The carbon-monoxide in smoke replaces oxygen in the hemoglobin (a component of blood), adversely affecting oxygen transport and energy supply, and requiring the heart to do more work to supply the same amount of oxygen to the body. A large number of smoke constituents, and particularly components of the gaseous phase of the tobacco smoke, cause immunologic responses and inflammation in the cells. This causes increased stickiness of the blood which increases the risk of clots. These processes increase the likelihood of a heart attack, stroke or other problems with the cardiovascular system.

Irritants such as nitric oxide cause hypersecretion of mucus and substances such as acrolein, acetone and acetaldehyde cause damage to the small hair-like strands that line the airways (cilia). This damage to the cilia impairs the ability of the cilia to clear mucus, causing breathi9ng difficulties. Years of smoking and daily coating of the lungs and airways in tar leads to irreversible lung damage and ultimately death from COPD .

Acute nicotine (critical for the development of addiction), increases heart rate, blood pressure and causes peripheral vasoconstriction (i.e. impairs peripheral circulation and thus exacerbates Reynauds’ Disease and erectile dysfunction). However, studies of smokeless tobacco users (who have high nicotine exposure like smokers, but without the smoke) compared with smokers, suggest that most of the cardiovascular problems are not caused by nicotine. It therefore appears that it is the thrombogenic effects of tobacco smoke exposure (primarily oxidant gases), combined with reduced oxygen supply (carbon monoxide) and increased myocardial oxygen demand (nicotine) that cause the cardiovascular harms from smoking.

Some of the chemicals found in cigarette smoke are listed below.

Carbonyls
Formaldehyde, Acetaldehyde, Acetone, Acrolein, Propionaldehyde, Crotonaldehyde, Methyl-Ethyl-Ketone, Butyraldehyde
Phenolics
Hydroquinone, Resorcinol, Catechol, Phenol, Cresol (m+p and o)
Aromatic Amines
3- and 4-aminobiphenyl, 1- and 2- aminonapthlene, o-toluidine, o-anisidine
Oxides of Nitrogen NO,
Hydrogen Cyanide
Ammonia
Volatiles
Benzene, Toluene, 1,3-butadiene, Isoprene, Acrylonitrile
Semi-Volatiles
Pyridine, Quinoline, Styrene
Trace Metals
Nickel (Ni), Cadmium (Cd) Lead (Pb) Chromium (Cr) Arsenic (As) Selenium (Se), Mercury (Hg)
Tobacco Specific Nitrosamines
N-Nitrosonornicotine (NNN)N-Nitrosoanabasine (NAB) Nitrosoanatabine (NAT)4-(N-nitrosomethylamino)-1-(3-pyridyl)-1-butanone (NNK)
Volatile Nitrosamines
N,N-Nitrosodimethylamine (NDMA)N-Nitrosopyrrolidine (NPYR), N,N-Nitrosodiethylamine (NDEA)N,N-Nitrosoethylmethylamine (NEMA), N,N-Nitrosodipropylamine (NDPA)N,N-Nitrosodibuthylamine (NDBA), N-Nitrosopiperidine (NPIP)
Polycyclic Aromatic Hydrocarbons
Naphthalene, 1-Methylnaphthalene, 2-methylnaphthalene, AcenaphthyleneAcenaphthene, Fluorene, Phenanthrene, Anthracene, FluoranthenePyrene, Benzo(a)anthracene, Chrysene, Benzo(b)fluorantheneBenzo(k)fluoranthene, Benzo(j)fluoranthene, Benzo(g,h,l)peryleneBenzo(e)pyrene, Benzo(a)pyrene, PeryleneIndeno(1,2,3,-cd)pyrene, Dibenzo(a,h)anthraceneDibenz(a,j)acridine, Dibenz(a,h)acridine, Dibenz(a,e)pyreneDibenz(a,h)pyrene, Dibenz(a,i)pyrene, Dibenz(a,l)pyrene7H-Dibenzo(c,g)carbazole,
Heterocyclic Aromatic Amines
2-Amino-3-methylimidaszo(4,5-f)quinoline (IQ)2-Amino-3,4-dimethylimidazo(4,5-f)quinoline (MeIQ)2-Amino-3-methyl-9H-pyrido(2,3-b)indole (MeAaC)2-Amino-9H-pyrido(2,3-b)indole (AaC)1-Methyl-9H-pyridol(3,4-b)indole (Harman)9H-Pyrido(3,4-b)indole (Norharman)

Labels: cancer, chemicals, cigarette, jonathan foulds, nicotine, smoke, tar, toxins

Permalink and Comments | | Email Post