天然放射性物质

天然放射性物质是怎样经过生物圈进入人体？

How does natural radiation enter our body through the biosphere ?

目的确定含天然放射性物质的物料是否处于非长期平衡，以及衰变链中那些长寿命核素被分离或减少。

Objective To determine materials containing natural radionuclides in or out secular equilibrium with their parents or daughters .

辐射来自于外层空间（宇宙射线），以及在土壤，水和空气中的天然放射性物质。

The radiation comes from space ( cosmic rays ) as well as natural radioactive materials found in the soil , water and air .

测定了在该泉水中养殖的鱼类及用该泉水灌溉生长的农作物和其他有关环境生物样品中天然放射性物质的含量。

The natural radioactive substance content was determined for fishes , in thermal spring water , farm products irrigated with such water and other biological samples .

建筑物，无论是民用建筑，还是工业建筑，所用建筑材料（建筑主体材料、装饰材料）都不同程度地含有天然放射性物质。台北101大楼的主要用材与施工

In buildings , whether civil or industrial , natural radioactivity always occurs at different de-grees in the materials ( main building materials , decorative materials ) . Main Building Materials and Construction for Taipei 101

研究表明，绝大多数天然宝石所含放射性物质是极其微弱的，故不会对人体健康构成危害。

The research result shows most natural gems contain so little radioactive minerals that they can 't he harmful to health .