Toxicity and radioactivity

Toxicity is a relative measure intended to indicate how harmful a mineral is to the human body. The type of exposure to a toxic mineral plays a significant role. In particular, the state in which the mineral is present is crucial. Dusts or fine fibers (e.g., in the case of asbestos) are much more easily absorbed through the respiratory system or skin. In the event of ingestion (e.g., by small children) of certain minerals, extreme caution is advised, and a poison control center or emergency services should be contacted immediately.

Toxicity depends primarily (with the exception of asbestos, for example) on the problematic elements contained in the mineral. Certain elements can interact negatively with our bodies. For example, they bind to specific enzymes or damage the organism at the cellular level. Harmful elements include mercury (Hg), nickel (Ni), copper (Cu), chromium (Cr), cadmium (Cd), lead (Pb), arsenic (As), antimony (Sb), and thallium (Tl). There are also a few exceptions with high toxicity, such as villiaumite (NaF), witherite ( _BaCO₃ ), and readily soluble compounds containing barium (Ba), such as bromellite (BeO) or behoite [Be(OH)₂]. The asbestos minerals chrysotile, actinolite, anthophyllite, grunerite, riebeckite, and tremolite also pose a risk due to nanometer-scale fibers that can penetrate the lungs.

In addition, all radioactive elements and minerals are harmful to the human body. Since most minerals primarily emit alpha radiation, oral or inhalational ingestion is particularly problematic. The two most common radioactive elements in the mineral kingdom are uranium (U) and thorium (Th). Because thorium is usually substituted with other rare-earth elements (REEs), REEs such as cerium (Ce), lanthanum (La), neodymium (Nd), or yttrium (Y) can also indicate a low uranium (U)/thorium (Th) content and thus also a sign of radioactivity and, above all, toxicity in the mineral.

Radioactivity can be measured in various units. Becquerel ( Bq ) is the SI unit for the activity of a radioactive source and is used to indicate the number of decays per second in a sample. Sievert ( Sv ) is used to measure the effective radiation dose, which takes into account the biological effect of absorbed radiation on the human body. Other units include gray (Gy), curie (Ci), rad, and rem.

Especially when working with the aforementioned minerals (grinding, polishing, assembling), laboratory-like safety conditions should be maintained. This means a well-ventilated room, wearing gloves, safety glasses and a respirator, as well as storing the materials in labeled and sealed containers.