Since the beginning of Russia's invasion of Ukraine, iodine sales have been on the rise across Europe, with shortages recently being reported in Finland. Here, the government recommended that every household has a single dose of iodine tablets, in case of a nuclear event, leading to the shortages in pharmacies.
Elsewhere across Europe – including in Bulgaria, Poland, and the Czech Republic – there have been reports of people buying iodine in the belief that it offers protection in the event of a nuclear war.
While potassium iodide can protect you against certain types of radiation, experts and various nuclear authorities across Europe have stressed that taking the tablets is not necessary for many people and that it won't help in the event of a nuclear strike.
If you are aware of the association between iodine and nuclear radiation, it may be due to the nuclear accident at Chernobyl. During the meltdown of the nuclear power plant, a radioactive form of iodine – iodine-131 – was emitted from the core of the reactor. Iodine-131 is readily absorbed by thyroid glands, and with a half-life of eight days, it will sit there doing radioactive damage to your DNA and the surrounding tissue. It's approximated that 270,000 people in the area developed cancers, who wouldn't have done if the incident had not taken place, largely due to iodine-131 contributing to thyroid cancers.
However, there is one non-radioactive isotope of iodine that can help stop your body from absorbing the radioactive form: Iodine 127. Just four neutrons different to its fatal, cancer-causing counterpart, Iodine 127 is radioactively stable, and so will not cause radioactive damage to your body. It works by sating your body's thirst for iodine, providing it with all the iodine it can handle. As does potassium iodide – the salt of non-radioactive iodine and potassium.
"When a person takes the right amount of [potassium iodide] at the right time, it can help block the thyroid from absorbing radioactive iodine," the US Centers for Disease Control and Prevention explains. "This happens because the thyroid has already absorbed the [potassium iodide] and there is no room to absorb the radioactive iodine. Think of filling a jar with blue marbles. If you then pour green marbles over the jar, there will not be room and they will just spill out."
During the Chernobyl incident, potassium iodide was given out to the population. Though it's not possible to gauge how many lives it saved, the United Nations Children’s Fund (UNICEF) says if it had been more widely distributed it could have saved many more children from developing thyroid cancer.
While potassium iodide may be useful against iodine-131, other types of radiation are emitted by these disasters. What's more, taking it would only be useful in the event of a nuclear accident, and would not reverse damage that has already been done. Taking it can also cause rashes and inflammation, as well as severe illness and death in large quantities.
Though governments such as Finland are advising people have a dose on hand, it is because of potential threats caused by Russia taking over nuclear power plants, rather than any worries about the possible use of nuclear weapons. Governments are also advising that you do not need to take them until you are told.
"The current situation in [Ukraine] does not require the intake of [iodine tablets]," the Federal Agency for Nuclear Control Belgium tweeted, "these will remain available free of charge at the pharmacy, but are not necessary in this specific case. Only take iodine on the advice of the government."
In the event of a nuclear attack, iodine tablets would provide little protection according to Brooke Buddemeier, a health physicist and expert on radiation at Lawrence Livermore National Laboratory. Radioiodine only makes up around 0.2 percent of the total exposure you would face outdoors, Buddemeier explained to Business Insider in 2017.
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