The ordinary cigarette is a product composed initially of about 600 different substances. I say initially because, when lit, the combustion process generates a huge amount of new substances, making a single cigarette and its smoke contains over 7,000 different chemicals. Of these, 400 are notoriously toxic and at least 70 are known carcinogens, that is capable of causing cancer.
Among the hundreds of harmful cigarette substances we mention acetone (used as solvent enamels, paints and varnishes), ammonia (used in cleaning products, fertilizers), arsenic (present in rat poisons, pesticides and herbicides) and carbon monoxide (toxic gas coming out of the tailpipes of cars).
Despite the above information already sufficient to say that smoking is an extremely toxic and dangerous products, oddly enough, the reality is even worse. Besides all these toxic chemicals, cigarette smoke also contains highly radioactive substances such as polonium-210 and lead-210.
But if you're surprised to have never heard that cigarettes are products that emit ionizing radiation, be aware that this information is already known by the scientific community since the 1960s By the way, there are at least 50 years, the tobacco industry is aware of presence of radioactive elements in their cigarette and does nothing to remove them. On the contrary, all the research on the subject sponsored by the industry have been hidden from the public in recent decades.
In this article we will explain in detail what kind of radiation cigarette produces, which is the quantity and what are its risks for smokers and the people around them.
Before we talk specifically about the radiation of cigarettes, it is necessary to clarify basic concepts of the term radiation. Understanding this part of the text is important for you, further, can have the dimension of how severe the radiation that a smoker is exposed over smoking decades.
Most people when they hear about radiation immediately think of radioactive materials produced by nuclear or atomic bombs plants. But being exposed to radiation is extremely common, much more than you think. Radiation is any energy propagation from one point to another. For example, the electromagnetic waves of the radio, the TV stations, cellular telephones, microwave devices and the very light are forms of radiation. These radiations, however, are harmless, since they are part of the group of non-ionizing radiation.
It is considered that ionizing radiation has sufficient energy to strip electrons from atoms, or they are able to ionize atoms. In our body atoms ionization by ionizing radiation causes DNA damage, chromosomes and cellular proteins. When the exposure is high and acute, it is usually lethal, as were the cases of radiological accident in Goiânia with Caesium-137 and the Chernobyl nuclear accident, both in the 1980s but the exposure to ionizing radiation is dangerous even in doses low, if it is frequent, since it is associated with an increased risk of cancer formation.
The interesting thing about this story is that ionizing radiation does not originate only in radioactive materials produced by man, there are ionizing radiation from natural sources in the air we breathe, the food we eat, the walls of the buildings and the ground we walk on. There are also radiation of cosmic origin that reaches our planet, but that is fortunately filtered in large part by our atmosphere and the Earth's magnetic field. The amount of ionizing radiation received at high altitude is greater than the amount we receive when we are at sea level. During a plane trip, for example, received more radiation than usual.
Of course, the total amount of ionizing radiation in these sources cited above is minimal, not enough to cause damage to our health. Therefore, background radiation we call the amount of ionizing radiation that our environment issues naturally, much of it by the presence of the chemical element radon in the air.
See the table below the amount of ionizing radiation that some natural and artificial sources emit. The unit for measuring radiation used below is the millisievert (mSv):
natural ionizing background radiation a person is exposed to over 1 year at sea level - 2 to 3 mSv (depending on location).
This ionizing radiation in a banana (due to radiation produced by potassium) - 0.0001 mSv.
Ionizing radiation present in 100 grams of Brazil nuts (more radioactive food known, rich in potassium and radio) - 0.01 mSv.
Ionizing radiation from a single X-ray tooth - 0.005 mSv.
Ionizing radiation of a single chest X-arm - 0.01 mSv.
Ionizing radiation of a single chest X-ray - 0.02 mSv.
ionizing radiation over a year for a house built by stone, brick or concrete - 0.07 mSv.
Ionizing radiation a person is exposed in a transatlantic plane trip - 0.08 mSv.
average annual dose of radiation than a nuclear plant worker receives - 0.18 mSv.
Ionizing radiation from a single CT scan - 2 mSv.
Ionizing radiation that a person currently receives if it is for 1 hour at the Chernobyl nuclear power plant - 6 mSv.
Ionizing radiation from a single CT scan of the abdomen - 8 mSv.
Average dose of ionizing radiation received by the crew of transatlantic flights over 1 year - 9 mSv.
maximum annual dose of ionizing radiation allowed by law for a person who works with exposure to radiation - 20 mSv.
annual dose of ionizing radiation clearly associated with the emergence of cancers - 100 mSv.
ionizing radiation dose received in a short period of time can cause immediate changes in blood cells - 100 mSv.
ionizing radiation dose received in a short period of time can cause symptoms of poisoning radioactivity - 400 mSv.
ionizing radiation dose received in a short period of time that is potentially fatal - 4000 mSv.
Average dose of ionizing radiation received by Chernobyl workers who died in the first month after the accident - 6000 mSv.
ionizing radiation dose received in a short period of time that is fatal even with prompt medical attention - 8000 mSv.
Now that we have a basic understanding of the dangers of ionizing radiation and radiation doses of various natural and artificial sources, we can focus our article on radioactivity cigarette.
Cigarettes are radioactive because they contain polonium-210 and lead-210. These elements penetrate the tobacco crops because of the type of fertilizer commonly used for its cultivation. Once the tobacco sheet absorbs radioactive elements, there is no way to remove them.
Scientific studies published in the last 50 years show that a person who every day smoke a pack and a half of cigarettes over a year receives about 4.6 mSv of radiation caused by the presence of polonium-210 and lead-210. This amount of radiation, which is about 50 to 100% higher than the natural background radiation, does not seem, at first glance, something very serious. The problem, however, is how these radioactive elements accumulate in the lung. In smokers, the cigarette tar this tends to deposit in areas of bifurcation of bronchi can absorbing relevant amounts of radioactive polonium and lead.
This accumulation of radioactive material in the bronchi exposes the lungs of the smoker to high levels of radiation. A person smoking about 30 cigarettes per day (first pack and a half) receives up to over a year radiation 80 and 160 mSv at certain points of the lung. Note the severity of radiation dose. If we use the lower estimate radiation (80 mSv per year), yet the daily consumption of 1.5 pack of cigarettes a year is equivalent to:
Cumulative radiation equivalent to 4,000 chest X-rays.
444 times more annual radiation that a worker of a nuclear power plant receives.
40 times more than the natural background radiation.
4 times the maximum annual dose permitted for people who work with radiation.
If we say that there is accumulation of radioactive material in the smoking lung, it is natural that you immediately question if your friend or family member smoker who is on your side is a potential source of radiation. The answer is yes and no.
The answer is yes, if you dwell together and you are a passive smoker. About 75% of the polonium-210 present in cigarette smoke is not absorbed by the smoker himself and ends up spreading through the air and can be inhaled by non-smokers around you. The total amount of polonium-210 absorbed by passive smokers is unknown, but over years of exposure it is likely to be relevant.
On the other hand, the answer is no, if your contact with the smoker to give only when he's not smoking. Although there radioactive material deposited in the lungs of smokers, the radiation emitted by the Po-210 alpha is of the type which has low ability to penetrate the tissues. This therefore means that radioactive action of Po-210 is restricted to small regions of the lungs, only where there is storage of radioactive material. You can even hug your friend smoker, no extra radiation will reach you.
