Acute exposures overwhelm the body's natural ability to repair the damage.

急性暴露压垮人体自然修复损害的能力。

That is the difference between acute and chronic exposure, and it is a difference most people understand.

这就是急性暴露和慢性暴露的区别，大多数人都能理解这两者的不同之处。

An acute exposure to one sievert will probably cause nausea within hours, and four sieverts could be fatal.

一西韦特的急性暴露下可能会造成几个小时的恶心，四西韦特可以致命。

Fortunately, acute exposures are rare, but we are exposed daily to lower levels of ionizing radiation from both natural and man-made sources.

幸运的是，急性暴露很少见，但我们每天都暴露在较低级的电离辐射下既来自于自然，也来自于人造物质。

The biggest health risk occurs when lots of ionizing radiation hits us in a short time period, also known as an acute exposure.

最大的健康危害发生在大量的电离辐射在短时间内击中我们时，或急性暴露。