Around the country, people's basements can have a lot of radon, and home tests are available to test for radon.

在全国各地，人们的地下室可能有大量的氡，家庭测试可以测试氡。

There's one exposure that's well known to cause lung cancer, and that's radon exposure.

众所周知，有一种接触会导致肺癌，那就是氡暴露。

And radon is clearly associated with lung cancer when it's present in someone's house.

当氡出现在某人的房子里，它显然与肺癌有关。

Nuclear radiation comes from natural sources, like radon, a gas which seeps up from the ground.

核辐射来源于自然物质，例如氡，一种从地下渗出的气体。

The average person receives 6.2 millisieverts of radiation from all sources annually, around a third due to radon.

平均每个人每年累计接收6.2毫西韦特辐射，大约三分之一是氡。

Some of these atoms occur naturally -- like in radon gas -- but many others don’t.

其中一些原子是自然产生的——比如氡气——但许多其他原子则不会。

All this background radiation comes from radon in the air and uranium and thorium in the soil.

所有这些背景辐射都来自空气中的氡和土壤中的铀和钍。

For example, if the parent nucleus is radium, it would decay into radon and emit a single alpha particle.

例如，如果母核是镭，它会衰变为氡并发射单个 α 粒子。

Note that the atomic number of radon is just two units less than that of radium, and the mass number is four less than radium’s.

请注意，氡的原子序数仅比镭少两个单位，而质量数比镭少四个。

In 2011, just before an earthquake struck the east coast of Japan, nearby researchers recorded surprisingly high concentrations of the radioactive isotope pair: radon and thoron.

2011年，就在地震袭击日本东海岸之际，附近的研究人员侦测到了高浓度的放射性同位素组：氡和钍，对此他们十分震惊。