Still potentially deadly after all these years: how to safely handle and display radioactive dinosaurs and other fossils

Abstract

Most curators and collection managers responsible for a geological collection will be aware of the risk posed by rocks and minerals which emit ionising radiation and will have put measures in place to reduce this risk to collection users. However, fewer people are aware that fossils, ranging from fish to dinosaurs, and even coprolites can be radioactive too. A fossil may be radioactive if it has been exposed to uranium-bearing fluids during diagenesis and fossilisation processes. Any uranium-enriched groundwater moving through nearby porous deposit can contaminate the rocks and fossils with radioactive elements. Over time the skeletons or other remains being fossilised incorporate these elements into their min- eral structure, such that the concentration of radioactive elements in fossils may be greater than that in the host rock. The greater the volume of fossil material, e.g. a large dinosaur bone, the greater the potential for higher levels of radioactivity, and a greater risk to hu- mans (although some small specimens can be highly radioactive). Whilst most radioactive fossils may not present a danger to health through direct absorption of radiation, unless there is prolonged exposure at close quarters (e.g. hundreds of hours), a risk is posed by the ingestion or inhalation of small radioactive particles derived from the specimen. Here, we describe what measures can be taken to reduce these risks and also provide a list of locations around the world known to yield radioactive fossils, which we hope can be augmented by others. The general principles discussed here are widely applicable, but it is recommended that specialist advice is sought to comply with national regulations in each instance. In ad- dition to the health risks posed by these specimens, there are also legal penalties for failing to comply with regulations.