What Chemicals Are In Cigarettes?

Lucy Bell-Young

by Lucy Bell-Young

30th September 2020

Despite the known harmful chemicals in cigarettes, as well as their high taxation and all the anti-cigarette warnings issued by governments, cigarette manufacturing is still a very profitable business. Did you know, for example, that the total global revenue from cigarettes in 2020 is estimated at a whopping £547,524,602,650? The annual global profits from cigarettes aren’t any more reassuring, with estimates sitting at around £26,947,725,000.

More than this, the number of annual deaths associated with smoking exceeds eight million, with around seven million deaths caused by direct smoking, and 1.2 million caused by inhaling second-hand smoke. Behind these figures are scientific explanations detailing why tobacco is so deadly, and this is what this article will explore as we expose the science behind tobacco toxicity.

How Many Chemicals Are In Tobacco?

‘Tobacco’ isn’t actually the name of a single species of plant, but a common name for various plant species belonging to the Nicotiana genus and the Solanaceae (nightshade) family of plants. More than 70 species of tobacco plants are known, but N. tabacum is the main species used in manufacturing cigarettes and cigars. Though it does have a more powerful variant, known as N. rustica, this isn’t commonly used in the commercial production of cigarettes.

More than 7,000 chemicals are found in tobacco. Many of these are toxic, and some even carcinogenic or mutagenic. When a person is exposed to these chemicals for a long period of time, they can develop illnesses like lung cancer, emphysema, and other related diseases. Even with filters, many of the toxic chemicals in cigarettes still get into the lungs, accumulating in the alveoli where they can deteriorate lung tissue.

The active substance that causes addiction in cigarettes is nicotine. This is a stimulant that’s similar to coffee, causing mental alertness and a sense of elation. Naturally, it’s classified as a parasympathomimetic alkaloid that serves as a natural insecticide that protects the tobacco plant. As a drug, it activates a part of the autonomic nervous system known as the parasympathetic division.

The chemical formula for nicotine is C₁₀H₁₄N₂, and it works by mimicking the effect of the primary neurotransmitter of the nervous system: acetylcholine (ACh). However, whilst this is one of the deadliest chemicals found in cigarettes, there are many others that aren’t talked about at all. In fact, not all of the harmful chemicals are even found in the tobacco leaves. Some are formed when they’re cured after being harvested, or when they’re processed in factories. Meanwhile, other chemicals are only formed when a cigarette is actually lit. 

Structural model of Nicotine on the blackboard.

Nicotine is the active substance in cigarettes that causes addiction

What Are The Most Harmful Chemicals In Cigarettes?

One cigarette alone contains more than 70 chemicals that are harmful to your health. These can cause heart disease, an assortment of cancers (particularly lung cancer), strokes, diabetes, chronic obstructive pulmonary disease, and infertility. Here are some of the most harmful chemicals found in cigarettes, aside from nicotine:

  • Cadmium (Cd): This is a heavy metal, which can cause cancer and organ toxicity. It can affect the skeletal, urinary, cardiovascular, as well as the nervous system.
  • Lead (Pb): Lead is another heavy metal that can drastically affect the brain. It can cause intellectual disability in developing foetuses. It can also cause infertility and memory loss among adults.
  • Acrolein (C3H4O): This is a highly toxic substance that can irritate the eyes, mucous membranes, and the respiratory tract. 
  • Acetaldehyde (C2H4O): This substance can destroy DNA, making it both a mutagenic and carcinogenic chemical.
  • Benzene (C6H6): Long-term exposure to this chemical harms the blood. Since it affects the bone marrow, it causes a decrease in red blood cells, which leads to anaemia. It’s also a carcinogen.
  • Ammonia (NH3): This is a highly toxic substance that affects the consciousness in small concentrations of only 100 µmol /L. At 200 µmol /L concentration, it can induce comas and cause convulsions 
  • Carbon monoxide (CO): Although odourless and colourless, this gas can be deadly at high concentrations. Even at low concentrations, such as in cigarettes, it can cause dizziness or drowsiness.
  • 1,3-Butadiene (C4H6): This substance can irritate the eyes and cause blurred vision. Other symptoms of toxicity are coughing and drowsiness, and chronic exposure can cause cancer.
  • Tobacco-specific nitrosamines (C10H13N3O2 and C9H11N3O): These chemicals form when tobacco leaves are cured, aged, and processed. These chemicals increase the risk of certain types of cancer in humans, like cancers of the oesophagus, oral cavity, and pharynx.
llustration showing harmful Chemicals in Cigarettes on black background.

One cigarette alone contains more than 70 chemicals that are harmful to your health

Why Do They Put Chemicals In Cigarettes?

When processed in factories, manufacturers add chemicals to tobacco leaves in order to control the moisture, enhance or add flavour (e.g. menthol), and mask harshness.

For instance, ammonia compounds are added to change the rate of nicotine absorption in the body. Sugar is also added to make the resulting cigarette less harsh, but this addition leads to the formation of acetaldehyde, which is a type of carcinogen that enhances the addictiveness of nicotine. Additionally, hundreds of additives are also incorporated during the manufacturing of cigarettes. What makes these additives worse is that they have cumulative effects that make cigarettes even more harmful. 

Many additives work together to enhance nicotine addiction. For example, some additives, like cocoa, cause the airways to dilate, allowing smokers to inhale larger amounts of smoke, thereby depositing a greater amount of tar into the lungs. The harshness of tobacco smoke on the throat is also reduced by the addition of additives that act as an anaesthetic. The main purpose of all these chemicals is to make the smoker more addicted, thereby boosting product sales.

What Chemical In Cigarettes Causes Lung Cancer?

Among the thousands of chemicals in cigarettes, about 69 of them are associated with different types of cancers. Some cause cancer directly by accumulating in the lungs, like tar, which damages the DNA of lung cells. Some chemicals, on the other hand, increase the risks of cancer in general. Here are some of the carcinogenic chemicals found in cigarettes:

  • Acetaldehyde
  • Aromatic amines
  • Arsenic
  • Benzene
  • Beryllium 
  • 1,3–Butadiene
  • Cadmium
  • Chromium
  • Cumene
  • Ethylene oxide
  • Formaldehyde
  • Polonium-210
  • Tobacco-specific nitrosamines
  • Vinyl chloride
Tobacco for cigarette production as vector flat illustration

Cigarette manufacturers add chemicals to tobacco leaves in order to enhance the cigarettes and increase addiction

The chemicals in cigarettes are incredibly harmful and the higher the reliance on them, the greater the risk is of developing cancer and other diseases. (The chemicals in e-cigarettes are considered “maybe safer”.) At the same time, a person who is addicted to nicotine can smoke for years or even decades before developing a serious illness, while someone who smokes for a short period may experience severe health effects even after just a year. It all depends on how each person’s body copes with the chemicals – but, of course, it’s best not to take the risk!


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