What The Heck Are TSNAs?
TSNA refers to tobacco-specific nitrosamines. These chemicals include some of the most dangerous carcinogens in tobacco which are classified as a Group 1 carcinogen by the International Agency for Research on Cancer. This means that TSNAs have been proven to cause cancer in humans.
TSNAs are present in a variety of tobacco products, including cigarettes, cigars and snuff and are mostly formed during the curing process for tobacco. TSNAs have been linked with many types of cancer and especially lung cancer, the form of cancer most commonly diagnosed in smokers.
Tobacco-specific nitrosamines, or TSNAs are a type of carcinogenic chemical found in tobacco, particularly tobacco smoke. While they are one of the many harmful and cancer-causing chemicals in cigarettes, they are not widely known outside of the tobacco industry and tobacco control groups.
The majority of TSNAs are created during the curing and processing of tobacco as well as during smoking when the tobacco combusts. The amount of TSNA in cigarettes varies as a result of different curing and manufacturing processes as well as growing conditions.
There are concerns being raised that the tobacco industry isn’t doing enough to reduce the levels of TSNA in cigarettes. And research suggests that the levels have actually been increasing in recent years.
The International Agency for Research on Cancer have proven that two TSNAs known as NNN and NNK cause cancer in humans. And these are not the only tobacco-specific nitrosamines that are linked to various forms of cancer.
How TSNAs Are Made
TSNAs are created during the tobacco curing and manufacturing process as well as when cigarettes are smoked and the tobacco combusts.
Tobacco contains nitrates which were absorbed from fertilisers as well as nitrate rich soils. These nitrates become the carcinogenic TSNAs when the tobacco is cured and processed causing the natural alkaloids found in tobacco to combine with the nitrates.
The levels of TSNA produced varies depending on how the tobacco is cured. This means that different tobaccos around the world contain more of these carcinogenic chemicals than others.
There are many ways to cure and process tobacco which influences the flavour as well as the levels of TSNA.
Air-cured tobacco is hung in a barn and allowed to dry by the flow of air alone over a period of several weeks. Air-cured tobacco has a high nicotine content and has a light, sweet flavour. This method has been shown to produce high levels of TSNA.
Fire-cured tobacco is hung in barns where burning wood is kept at a low smoulder to produce heat. This process takes around a week and produces tobacco that is low in sugar and high in nicotine.
Flue-cured tobacco is hung in barns and dried using flues which carry the heat from fire boxes, heat-curing the tobacco without exposing it to smoke. This is the most common curing method for cigarette tobacco. Flue-curing takes about a week and produces tobacco that’s high in sugar with a medium level of nicotine. Research suggests that flue-curing tobacco produces the highest levels of TSNA although the amounts still vary from product to product.
Sun-cured tobacco is dried uncovered in the sun and this method is used in countries around the Mediterranean and southeastern Europe as well as south Asia. Sun-curing produces tobacco that is high in sugar and low in nicotine.
Fermentation is another part of the tobacco manufacturing process where the tobacco undergoes a second stage of curing. Not all tobaccos uses this method (also known as sweating) and it is believed that fermentation helps create high levels of TSNA.
Because the way tobacco is process affects the amount of tobacco-specific nitrosamines, there are concerns that tobacco producers aren’t doing enough to reduce the amount of TSNA in their products.
Health Risks, Levels In Tobacco, etc.
We already know that two of the TSNAs that can be found in cigarette smoke have been proven to cause cancer in humans and several more are also linked to cancer.
One form of tobacco-specific nitrosamine known as NNK is associated with lung cancer. Around 80% of people who suffered from lung cancer developed it as a result of smoking. TSNAs have also been linked to other cancers that smokers commonly develop such as liver and pancreatic cancer as well as oral and esophageal cancer.
Levels of TSNA in tobacco
The levels of TSNA in tobacco have varied significantly over time because of changes in the manufacturing process. Research has shown that the average levels of tobacco-specific nitrosamines have been increasing in the last decade.
It has been suggested that the tobacco industry is in a position to lower the amount of TSNA in cigarettes and that more should be done to achieve this. Although it is unclear how much difference this will make to the dangers of smoking considering the large number of harmful chemicals in cigarette smoke.
While there are many factors that influence how TSNAs are formed in tobacco, some of the biggest factors can be controlled during manufacturing. Campaigners are currently calling for new manufacturing standards in the hope of reducing the amount of carcinogenic tobacco-specific nitrosamines in tobacco products.
Tobacco-specific nitrosamines are a group of harmful chemicals found in tobacco products and most of them are created during the curing of tobacco as well as when it is burned. Two of these TSNAs are categorised as Group 1 carcinogens, proven to cause cancer in humans.
TSNAs are just one of many harmful chemicals found in cigarette smoke that make smoking so dangerous. But, as the level of TSNA can be affected by the manufacturing process, campaigners are calling for regulations to help reduce the amount of TSNAs found in tobacco products.
Reducing the number of harmful and carcinogenic chemicals in cigarette smoke is always a good thing. But the best way to remove these health risks is always going to be quitting smoking completely.