Why Iran Is Handing Out Iodine Tablets Near Its Nuclear Sites & How They Protect Against Radiation

Iran has reportedly begun distributing iodine tablets to residents living near its nuclear facilities, as fears grow that the United States could strike its atomic sites. The move, which signals preparation for a possible radiological emergency, comes as Washington weighs further military action and Iranian officials warn of wider retaliation. Attention has centred on Pickaxe Mountain, a heavily fortified complex near Natanz. The tablets protect only the thyroid, and experts say timing and the type of release determine whether they help.

The distribution was first reported by The Times of London, which cited an Iranian Health Ministry official. The official said authorities had sought to give the tablets to communities within two to three kilometres of nuclear installations during each war. "Yes, we are distributing iodine," the official told the paper, adding that Trump "can no longer be trusted." The official was not named, and the report did not say how many tablets have been handed out or which areas are covered.

How iodine tablets work

The tablets contain potassium iodide, a stable form of iodine. They saturate the thyroid with ordinary iodine, so it absorbs less of the radioactive iodine that can be released in a nuclear accident. One review found that when potassium iodide was given before exposure, thyroid uptake of radioactive iodine fell from an average of 20 percent to under 2 percent.

The protection has firm limits. The tablets do not shield against other radioactive substances or external radiation. The effect also lasts only a few days. Children face the greatest risk, which is why they are the priority group in most emergency plans.

Chernobyl: The Lesson Of Poland

The 1986 Chernobyl explosion showed what unprotected exposure can do. Belarus, Ukraine and Russia saw a significant rise in childhood thyroid cancer from radioactive iodine. Neighbouring Poland acted fast. It gave potassium iodide to more than 95 percent of its children within three days of the accident and saw no rise in thyroid cancer in the first three years of follow-up. A later review put the total at 95 percent of Polish children and 23 percent of the whole population.

Japan: Fukushima's Patchy Response

After the 2011 Fukushima disaster, Japan's use of iodine was uneven. A study found that seven local governments distributed potassium iodide tablets and only four gave instructions on taking them. The release was far smaller than at Chernobyl, about 10 percent as much radioactive iodine. A follow-up study found no significant adverse effects on thyroid function in children who took the tablets seven years on.

Ukraine and Zaporizhzhia

The same logic was applied in 2022. Ukrainian authorities handed out iodine tablets near the Zaporizhzhia nuclear plant after the plant was cut off from the national grid for the first time in its 40-year history. Officials stressed the tablets were for use only on government instruction, not as a preventive. Tablets taken too early or without cause give no benefit.