消核輻射恐慌 世衛組織權威解答核輻射疑問
世界衛生組織3月15日在其官方網站上發佈日本核爆炸事件相關問題集，爲民衆解答核輻射後如何保護自己的相關問題。其中特別提及：什麼是電離輻射？輻射會產生哪些急性健康問題？是否應該服用碘化鉀片？等。來看看有沒有提及你的疑問。
FAQs: Japan nuclear concerns
日本核爆炸事件相關問題集
1. What is the current risk of radiation-related health problems in Japan to those near the reactor at the time, and those in other parts of Japan?
目前就反應堆附近和日本其他地區來講，核輻射健康問題的威脅有哪些？
The actions proposed by the Government of Japan are in line with the existing recommendations based on public health expertise. The government is asking people living within 20km of the Fukushima Daiichi nuclear power plant to evacuate and those between 20 km and 30 km away from the plant are asked to stay indoors in unventilated rooms. People living farther away are at lower risk than those who live nearby.
日本政府提出的行動和目前和以公共健康專業知識爲基礎的建議是一致的。政府呼籲居住在福島核電站20公里以內的居民趕緊撤離，居住在距核電站20-30公里之內的居民呆在家裏，關閉門窗。居住在遠處的居民受到的威脅要比附近的居民受到的威脅要低。
This assessment can change if there are further incidents at these plants and WHO is following the situation closely. However, radiation-related health consequences will depend on exposure. Exposure in turn is dependent on the amount of radiation released from the reactor, weather conditions such as wind and rain at the time of the explosion, the distance someone is from the plant, and the amount of time someone is in irradiated areas.
如果這些工廠發生進一步的事故，該評估可能改變；世衛組織正在密切關注目前的局勢。然而，核輻射的健康後果取決於暴露的程度。反之，暴露程度取決於從反應堆釋放出來的輻射量，爆炸發生時的天氣情況，如風力和降雨，以及當時人們的位置與核電站的距離，人們在覈輻射區域呆的時間。
2. What is ionizing radiation?
什麼是電離輻射？
When certain atoms disintegrate, either naturally or in man made situations, they release a type of energy called Ionizing radiation (IR). This energy can travel as either electromagnetic waves (gamma or X-rays) or as particles (neutrons, beta or alpha).
當某些源原子分解的時候，無論是在自然條件下還是在人工條件下，它們都會釋放出一種被稱爲電離輻射的能量。這個能量能夠像電磁波（伽馬射線或X射線）或者粒子（中子，β或α）那樣傳播。
The atoms that emit radiation are called radionuclides.
釋放出輻射的原子被稱爲放射性核素。
The time required for the energy released by a radionuclide to decrease by half (i.e., the "half-life") range from tiny fractions of a second to millions of years depending on the type of atoms.
放射性核素釋放的能量減半需要的時間範圍是幾分之一秒到幾百萬年，取決於原子的類型。
3. Are people normally exposed to ionizing radiation?
人們通常都暴露在電離輻射下嗎？
Human beings are exposed to natural radiation on a daily basis. The radiation comes from space (cosmic rays) as well as natural radioactive materials found in the soil, water and air. Radon gas is a naturally formed gas that is the main natural source of radiation.
人類每天都暴露在電離輻射下。輻射來自於外層空間（宇宙射線），以及在土壤，水和空氣中的天然放射性物質。氡氣是一種自然形成的氣體，是主要的天然輻射來源。
People can also be exposed to radiation from human-made sources. Today, the most common man made source of ionizing radiation are certain medical devices such as X-ray machines.
人類同樣可能暴露在人爲來源的輻射下。當今，最主要的人爲來源電離輻射就是某些醫療設備，如X光儀器。
The radiation dose can be expressed in units of Sievert (Sv). On average, a person is exposed to approximately 3.0 mSv/year of which, 80% (2.4 mSv) is due to naturally-occurring sources (i.e., background radiation), 19.6 % (almost 0.6 mSv) is due to the medical use of radiation and the remaining 0.4% (around 0.01 mSv) is due to other sources of human-made radiation.
輻射劑量可以西弗特（Sv）爲單位。平均來說，一個人每年接觸到的輻射量約爲3.0毫西弗，其中，80％（2.4毫西弗）是由於自然發生源（即，背景輻射），19.6％（幾乎0.6毫西弗）是醫療使用的輻射和其餘0.4％（約0.01毫西弗）來源於其他人類活動。
In some parts of the world, levels of exposure to natural radiation differ due to differences in the local geology. People in some areas can be exposed to more than 200 times
the global average.
在世界上的有些地區，暴露在自然輻射下的程度會因爲當地的地理原因而不同。某些地區的人們可能暴露在高於全球輻射兩百倍的輻射下。
4. How are people exposed to ionizing radiation?
人們是如何暴露在電離輻射下的？
Ionizing radiation may result from sources outside or inside of the body (i.e. external irradiation or internal contamination).
身體的內部和外部都有可能成爲電離輻射的來源（外部照射或內部污染）。
Internal contamination may result from breathing in or swallowing radioactive material or through contamination of wounds.
內部污染，來源於吸入的或者是吞服的放射性物質，或者通過傷口污染。
External irradiation is produced when a person is exposed to external sources such as X-rays or when radioactive material (e.g. dust, liquid, aerosols) becomes attached to skin or clothes, resulting in external contamination.
當一個人暴露在外來輻射源如X光下，或者當皮膚接觸到放射性物質（如灰塵，液體，氣霧劑）時，外部照射就產生了，其結果是外部污染。
External contamination can often be washed off the body.
身體外部的污染可以被洗掉。
