After Japan's disaster it seems everyone is worried about radiation. Radiation cannot be seen, but if we get a lot of it, it can kill us. It can hang around on our food and in our water too. So here's what you need to know about the radiation crisis:
Where does the radiation come from? The radiation is leaking from nuclear power plants in Fukushima, northern Japan, that were damaged by the tsunami. Parts of the plants which generate electricity need to be cooled. The cooling system was damaged by the tsunami and quake. When the nuclear reactor's core gets too hot it melts and allows radiation to escape. Right now brave workers are trying very hard to stop this from happening. But some radiation has already escaped and contaminated food and water, but only in Japan.
What foods might be contaminated? The World Health Organisation says we need to be careful about leafy green vegetables and animal products like milk or eggs from Japan. Canned goods should be okay because their raw materials will be scanned before use to make sure they are not contaminated.
Who is at risk? Nobody is really at risk in Hong Kong unless there is a much bigger release of radiation in Japan. Children and young people are most at risk. The radiation damages the thyroid gland in the throat. This gland absorbs iodine. Part of the radiation coming from the plant is also iodine and so will be absorbed by the thyroid.
Why can't we protect ourselves with salt? You would have to eat a lot of salt to do any good. And you're more likely to die from the amount of salt you eat, than the radiation.
When will it be safe to eat Japanese food again? Right now, according to WHO. The amount of radiation on Japanese fresh foods is too small to cause any health risk.
How will the government protect us? It will check food from Japan with a special machine to see whether or not it is contaminated with radiation.