Smoke Gets in Your Lungs

In the present day, there's a lot of controversy about smoking. Old substances (tobacco) are in decline and are often under public disdain. "New" ones (marijuana) are in ascendance and are becoming more acceptable and may even cross the line back into legality (it's not really new and has a long history of various stages of legality -- see the Wikipedia entry Legal History of Cannabis).

However, because of its controversial legality and use, the health aspects of marijuana smoking have not been pursued as it has been for tobacco. There are also other substances that are sometimes smoked -- heated and inhaled or brought into the mouth. So, let's take a step back and just look into the smoke.

Smoke occurs when substances are burned. Many firefighter (and people trapped in fire areas)  injuries are associated with smoke inhalation. There are good (but highly technical) sources such as Wikipedia for articles on the various possibilities depending on factors such as heat, presence of other substances, humidity, and so forth. In this blog, we will concentrate on the tobacco and marijuana smoke voluntarily inhaled in relatively limited amounts by "smokers" and "tokers".

Smoke has four major aspects: carbon monoxide, tars and particulates, active ingredients, and additives.

1. Carbon Monoxide. This gas is created by incomplete burning of the material. It is primarily a danger to those "inhaling" as it is more lung-related. It is present in all smoke in varying degrees and is considered to be a poison as the body will absorb it and it decreases general function and may cause death. It is absorbed into the blood cells and decreases the ability to absorb oxygen and, thus, reduces stamina and general ability to perform at optimum levels. There is little difference in the effects between tobacco and marijuana smoke.
   
   
2. Tars and Particulates. These are the visible parts of smoke -- if you can see it, they are present. They are what cause the darkened areas of X-rays of lungs. "Tars" are resinous substances -- usually quite sticky and they cause the staining of teeth (and lungs) and can act as a kind of glue in the lungs, reducing the ability of the lungs to absorb oxygen. The particulates can vary in size depending on the temperature of the burning material and the size of the parts being burned and can act as an irritant causing more mucous production which is a major cause of "smoker's cough". It takes about five years for the lungs to fully repair from the damage caused by these substances and is considered to be a major trigger of lung cancer. This area could use more study but it is likely that there is little difference between tobacco and marijuana smoke.
   
   
3. Active Ingredients. These are the substances that interact with other parts of the body to cause the effects anticipated by smokers and tokers. In tobacco, this substance is nicotine which has many effects but primarily acts as a stimulant. It also has a mile diuretic (body water removing) effect which may cause weight loss for beginning smokers (and cause some temporary weight gain after quitting). It is water-soluble and, thus, is ideally administered via smoking. Anecdotally, nicotine is considered to help general focus and mental activity but there are no controlled studies verifying this. Nicotine also tends to paralyze the cilia in the trachea (windpipe) and, thus, may increase mucous retention and coughing. There are a few minor medical purposes for nicotine but it is highly physically addictive
   
   The primary active ingredient in marijuana is tetrahydrocannabinol (usually referred to, for obvious reasons, as THC). Its effects vary from individual to individual and is considered primarily a "psychoactive" (acting primarily on the central nervous system) drug. Common effects include increased appetite, decreased nausea and pain, and a reduced sperm production in men. It is not considered to be highly physically addictive although a varying amount of emotional or psychological addiction is possible for both marijuana and tobacco.
   
   
4. Additives. Since tobacco has been legal for many years and is a highly competitive industry, each company does what it can to both distinguish and "enhance" its brand of tobacco. Glycerin is normally added to increase shelf life and prevent the tobacco from drying out. Formaldehyde (think of frogs in jars in biology class) is added to make absorption and crossover to the brain more rapid. This increases the risk of physical addiction. Many other additives are also present -- from spices such as cinnamon and cloves to liquids such as menthol and other oils. Formaldehyde is known as a carcinogen and the burning by-products of the other additives have not been extensively tested. However, this is an area that is highly likely to contribute to act as cancerous triggers (especially for non-lung-related cancers). Tobacco is much worse in this area than marijuana.

Inhaling or not inhaling? As a water-soluble drug, the effects of nicotine are dependent upon the surface area times the duration of exposure. This is also true for other additive burn by-products. Thus, inhaling would be worse if holding it in the mouth was done for the same amount of time. However, this is not actually the case as cigar and pipe smokers tend to allow the smoke to remain in their mouths longer. Thus, there may be close to the same exposure for nicotine and additives. However, there would still be greatly reduced effects from the carbon monoxide and particulates. With THC, it varies upon the general environment. It is not considered to be water-soluble but it IS lipid (fats) and alcohol-soluble so, if taken with food or drink, it is probably absorbed as readily (or more readily) than bringing into the lungs.