Radioactivity – good or bad?

Have you used any ionizing radiation lately? Are you sure? Maybe you have a smoke detector at home. They often use alpha radiation to detect smoke in the air. Or you might have eaten some irradiated food?

Some parts of the world actually treat foods with ionizing radiation. It kills bacteria and parasites -- sterilizing the food. When food reaches your plate it's quite safe. There isn't any radiation left in it. It's just like light.

Light isn't stored in food just because you shine a lamp on it. Even needles and other medical equipment can be sterilized with radiation. You might also have used ionizing radiation at the doctor’s or dentist’s, if you had an X-ray. Ionizing radiation has been used for a long time on Earth. The scientist Marie Curie built X-ray clinics for the French military doctors during the First World War.

The equipment was placed in cars so it could be moved with the front lines. Using X-rays, doctors could detect bullets and shrapnel before operating on injured soldiers. This saved many lives. Today, there are many ways for medical personnel to take pictures using ionizing radiation. This patient is drinking a small amount of a radioactive substance that collects in a part of the body that needs to be examined.

Then, the doctors can see the radiation from the substance with a special camera. Ionizing radiation can also be used to treat cancer. Here is a patient with lung cancer. The doctor has aimed the beam of radiation precisely so that it only hits the tumor, and kills the cancer cells. During the Second World War, scientists, unfortunately, discovered another way to use the ionizing radiation: as a weapon.

If you load a bomb with radioactive material, you get a much greater explosive force than you would otherwise have had. The explosion leads to a rapid radioactive decay that creates a huge amount of energy. In the middle of July in 1945, the first atomic bomb was tested in a desert in the USA. Just three weeks later, a nuclear bomb was used for the first time. American planes dropped two bombs loaded with a radioactive substance over the Japanese cities of Hiroshima and Nagasaki.

In Hiroshima, about 100,000 people were killed by the pressure wave from the explosion, the radiation and the fires that followed. In Nagasaki, about 70,000 people died. Several thousand of the survivors died later of cancer that they got because of the radiation. Nuclear weapons have not been used in the war ever since, but they still exist in several countries. Several thousand tests have been carried out to develop the weapon.

Every time, the mayor of Hiroshima has sent a telegram to the responsible country asking for all nuclear weapons to be destroyed. Many of the world's countries have signed agreements to stop carrying out more tests. But the agreements have not been signed by all of the countries that actually have nuclear weapons. Ionizing radiation in health care saves lives. Ionizing radiation in war would be devastating.

These two things are pretty obvious. But it's not always so simple. Ionizing radiation is also used in nuclear power stations. There, radioactive decay creates energy that is used to produce electricity. Nuclear power is a relatively "clean" way to create electricity.

When everything works as it should, nuclear power produces no exhaust that damages nature or changes the climate. Therefore, some people believe we should produce more electricity this way. But if there is an accident at a nuclear power station, the radioactive substance could leak out, and the consequences could be terrible. This has happened. In addition, nuclear power stations produce dangerous waste that we have to store in a safe place, for many thousands of years.

This is why some people believe we should stop using the nuclear power. You have probably had more benefit from ionizing radiation than you knew. But you also share the risks of radiation with all of humanity. A nuclear war would wipe us out. And dangerous waste could spread to several countries after an accident at a nuclear power station.

We need to consider together which risks we think are worth taking -- and which risks we want to try to get rid of.