What are anti-radiation pills?

Source: By The Indian Express

With fears of a nuclear disaster at Ukraine’s Zaporizhzhia power plant growing, the European Union has decided to pre-emptively supply 5.5 million anti-radiation pills to be distributed among residents in the vicinity.

Those being handed out the pills are being told to only take them once a radiation leak has been confirmed. What are anti-radiation pills, and how do they protect people in case of a radiation emergency?

What is a radiation emergency?

These are unplanned or accidental events that create radio-nuclear hazard to humans and the environment. Such situations involve radiation exposure from a radioactive source and require prompt intervention to mitigate the threat. Dealing with such an emergency also involves the use of anti-radiation tablets.

What are anti-radiation pills?

Potassium iodide (KI) tablets, or anti-radiation pills, are known to provide some protection in cases of radiation exposure. They contain non-radioactive iodine and can help block absorption, and subsequent concentration, of radioactive iodine in the thyroid gland.

How do these pills work?

After a radiation leak, radioactive iodine floats through the air and then contaminates food, water and soil.

While radioactive iodine deposited during external exposure can be removed using warm water and soap, according to the World Health Organisation, the bigger risk is inhaling it.

Internal exposure, or irradiation, occurs when radioactive iodine enters the body and accumulates in the thyroid gland,” says the WHO.

The thyroid gland, which uses iodine to produce hormones to regulate the body’s metabolism, has no way of telling radioactive from non-radioactive iodine.

Potassium iodide (KI) tablets rely on this to achieve ‘thyroid blocking’. KI pills taken a few hours before or soon after radiation exposure ensure that non-radioactive iodine in the medicine is absorbed quickly to make the thyroid “full”.

“Because KI contains so much non-radioactive iodine, the thyroid becomes full and cannot absorb any more iodine – either stable or radioactive – for the next 24 hours,” says the US Centre for Disease Control and Prevention.

But KI pills are preventive only and cannot reverse any damage done by radiation to the thyroid gland. Once thyroid gland absorbs radioactive iodine, those exposed are at a high risk of developing thyroid cancer.

Is the method fool-proof?

Anti-radiation pills do not provide 100% protection. “The effectiveness of KI also depends on how much radioactive iodine gets into the body and how quickly it is absorbed in the body,” says the CDC.

Also, the pills are not meant for everybody. They are recommended for people under 40 years of age. Pregnant and breastfeeding women are also advised to take them. While it can protect the thyroid against radioactive iodine, it cannot protect other organs against radiation contamination.

Substitutes for KI

The US Food and Drug Administration advises against using salt or iodine supplements as they do not contain enough iodine to trigger thyroid blocking.