Radioactive iodine (including iodine 131) is a substance that can be released during a nuclear accident. It can be absorbed by the body through the respiratory tract or contaminated food and disrupt the thyroid gland. What is the danger? Is there a risk of cancer? What to do in case of contamination? Risks and precautions.
[Mis à jour le 8 mars 2022 à 12h26] One nuclear accident can release radioactive materials likeradioactive iodine. This iodine can enter the body through the respiratory tract or the ingestion of contaminated food. What health hazards and risks? For the gland thyroid ? What are the warning symptoms of radioactive iodine contamination? How to protect yourself from it? What to do in case of contamination oraccidental exposure to radioactivity ? What is iodine 131? Know everything.
Definition: what is radioactive iodine?
Radioactive iodine is a chemical element that can, for example, be released duringa nuclear accident. The body, and particularly the thyroid (gland located in the lower part of the neck, below the larynx, producing hormones that regulate many functions of the body), needs a small amount ofnatural or stable iodine (therefore non-radioactive) to function properly. This small amount comes from the foods we eat. In the event of a nuclear accident, it isradioactive (or unstable) iodine who is released. This type of iodine is dangerous for health.
| Namely: radioactivity is a phenomenon that emits ionizing radiation that is invisible. We cannot smell them, touch them, or hear them, we can only measure them. Radioactivity can be natural (cosmic radiation) or artificial (resulting from human activities: operation of nuclear reactors, electricity production, food sterilization, radiology, radiotherapy, nuclear medicine, etc.). |
|---|
What is iodine 131?
Iodine-131 is one of the most dangerous types of iodine because it is extremely radioactive
Iodine-131 (symbolized 131I) is one of the most dangerous iodine isotopes (variants of the same chemical element) when released into the environment because it is extremely radioactive and it is the one that has the most tendency to attach the most to the thyroidindicates the radioactivity website, managed by the CNRS. It’s about “of an isotope that is important from a radiotoxicological point of view because of its great mobility in the environmentof its good assimilation in the body and its accumulation in the thyroid“. Iodine 131 is one of the isotopes released in the event of a nuclear accident serious. Significant quantities of iodine 131 were released during accidents at Windscale (United Kingdom) in 1957, to Three Mile Island (USA) in 1979 and at Chernobyl (Ukraine) in 1986. It should be noted that used in very small quantities, iodine 131 is of interest for the exploration of the thyroid and the treatment of certain thyroid cancers.
If radioactive iodine is released into the environment and without protective measures, the body would absorb too much radioactive iodine which would thus accumulate in the thyroid gland and interfere with its operation. Radioactive iodine can enter the body in several ways:
- By inhaling air containing radioactive iodine.
- By ingesting food contaminated with radioactive iodine
- By the skinin case of direct exposure with radioactive iodine
What is the danger of radioactive iodine?
If radioactive iodine is released, there is a risk of: ► CONTAMINATION : when there is contact with radioactive iodine. Contamination can be external (when the substance only comes into contact with skin, hair or clothing) or internal (when the substance has entered the body) ► IRRADIATION: when radioactive iodine has irradiated the body remotely and outside of it (without direct contact and physical between the body and the radioactive substance). |
During a nuclear accident, a radioactive emission can occur, in the air, water or on the surface and release radioactive materials such asradioactive iodine in the environment. “Radiation is invisible, odorless and tasteless. Therefore, a radioactive emission can only be detected using specific measuring equipment“, explains the official site devoted to the nuclear risk of the Belgium Crisis Center. In the event of a nuclear accident, there is a real risk of contamination. Released into the environment, radioactive iodine can be iinhaled or ingested and end up in the body. This iodine can thus accumulate in the thyroid gland and saturate ituntil causing internal contamination. The thyroid gland is part of the endocrine system and secretes essential hormones that regulate the growth, development and metabolism of the body. Over the long term, internal contamination with radioactive iodine disturbs the thyroid, which considerably increases thyroid cancer risks. Massive exposure to radioactive substances also increases the risk of genetic malformations.
What are the symptoms of radioactive iodine contamination?
Symptoms usually only appearafter long exposure to radioactive material. Such a duration of exposure is a priori only possible for the workers and intervention personnel present in the installation where the nuclear incident occurred. In the general population, the risks are rarer, but exist. These signs can be:
- Vomitings
- Nausea
- Abdominal and neck pain
- Burns (inflammation of thyroid cells, salivary glands)
- Significant hair loss
Treatment: what to do in case of radioactive iodine contamination?
Iodine tablets do not protect against all the dangers of accidental exposure to radioactivity
To stop the thyroid gland from absorbing radioactive (unstable) iodine, you need to take treatment with iodine tablets stable (also called potassium iodide). The taking iodine tablets is one of the three measures that the Prefect can take in the event of a nuclear accident, along with sheltering and evacuating the population. This medicine prevents the thyroid from absorbing released radioactive iodine in the environment. Excess iodine will thus quickly passed out through urine. However, it does not protect against all the dangers of accidental exposure to radioactivity because it does not provide protection against other radioactive substances (such as cesium 134 or 137) potentially released. Hence the importance of taking shelter to avoid exposure.
→ The distribution of stable iodine is placed under the responsibility of the prefectsand is ensured at the level of the departments and regions, indicates the Institute for Radiation Protection and Nuclear Safety (IRSN). In other words, to be effective, these iodine tablets must be used at the right time, either when the competent authorities recommend taking them, insists FANC. For the moment, the situation in Ukraine, closely monitored by the European authorities, poses no health hazard. Having stable iodine tablets in this context is therefore not necessary.
What precautions to limit the risks of absorbing radioactive iodine?
To limit the risks of exposure to radioactive iodine, the competent authorities can take a series of measures and recommendations. For example :
- Shelter the population and impose stay insidedoors and windows closed, all ventilation, heating and air conditioning systems turned off, until the situation is safe again.
- Temporarily ban consumption of certain foods potentially contaminated such as milk, fruit or vegetables, meat…
- Temporarily ban tap water consumption.
The authorities and operators of nuclear sites ensure the safety to minimize the risk of a nuclear incident, ensure very strict controls and prepare contingency plans and procedures in case an incident occurs.
Sources:
– Site of the Institute for Radiation Protection and Nuclear Safety (IRSN)
– Nuclear risk (official website of the Crisis Center of Belgium)
– Federal Agency for Nuclear Control (AFCN)
– National Center for Scientific Research (CNRS) website