You are exposed only when you come into contact with the radioactive chemical. You can come into contact with it in the environment through breathing air, eating, drinking, or smoking substances containing the radioactive chemical. Exposure may also result from skin contact with the radioactive chemical alone, or with a substance containing it. Exposure can also occur by being near radioactive chemicals in concentrations that may be found at hazardous waste sites or at industrial accidents. If you are exposed to a hazardous substance such as uranium, several factors will determine whether harmful health effects will occur and what the type and severity of those health effects will be.
Natural uranium is a silver-colored metal that is radioactive.
Small amounts of uranium are present in rocks, soil, water, plants, and animals and contribute to the weak background radiation from these sources. This is equivalent to a tablespoon of uranium in a truckload of dirt. Fertilizers made from phosphate rocks contain higher amounts of uranium than natural soils. Some rocks and minerals in underground and open pit mines also contain uranium in a more concentrated form. After these rocks are mined, uranium is extracted and chemically converted into uranium dioxide or other usable forms.