Dysprosium is a chemical element with the symbol Dy and the atomic number 66.

Its name comes from the Greek 汛耒考羽老ό考牝而羊ς / dus-pr車sitos, "difficult to obtain".
Dysprosium is a rare earth metal, silver gray in appearance. Like other members of the lanthanide family, it is malleable, ductile, and soft enough to be cut with a knife. It is fairly stable in the air.

It cost a little more than 10 euros per kilogram in 2003, against more than 320 in 2011
It is an element whose use seems to be developing rapidly. Its soluble salts are considered to be moderately toxic and its insoluble salts as non-toxic. The pharmacological, toxicological and ecotoxicological properties of dysprosium chloride salts were evaluated in the 1960s, with the conclusion that their acute delayed toxicity and the symptoms they induce are comparable to those of other members of the same chemical group10, without impacts. visible in terms of histology, growth or haematological values ​​(on animals exposed for 12 weeks). But like holmium and erbium chlorides, dysprosium chloride has a depressant effect and induces death produced by respiratory paralysis associated with cardiovascular collapse10. Contact with the eye (experimentally) leads to transient conjunctivitis and ulceration10. It seems to have no short and medium term effect on healthy skin, but on abraded skin it causes abnormally deep scars with hair loss. Like its chemical colleagues, as a foreign body (experimentally administered intradermally) it provokes an immune reaction which is reflected in particular by nodules with giant cells and the formation of crystals10.

Tested as [166Dy] DyCl3 (with its radioactive isotope [166Dy]), it was found to be cytotoxic and genotoxic in the bone marrow (and therefore myelosuppressive), it was therefore proposed in 2004 as a possible radiochemotherapy agent for the treatment of certain cancers (myelomas, blood cancers) in humans (after initial tests in laboratory mice) 11.

Although data are still lacking on its systemic toxicology in humans and animals (as for lithium (Li) and zirconium (Zr)) and the chemical counterparts of dysprosium that are other "rare earths" such as yttrium (Y), neodymium (Nd), praseodymium (Pr), gadolinium (Gd), lanthanum (La), cerium (Ce), europium (Eu), lithium (Li ) and zirconium (Zr)), it is proposed to use it to improve the mechanical properties of alloys, including ※absorbable§ (more than actually biodegradable) magnesium12 alloys intended to be surgically implanted in the human body13. According to a recent study (2010), however, it is less cytotoxic than lanthanum and cerium

rhenium    germanium    zirconium     cadmium     hafnium

      barium   lithium     beryllium     strontium     calcium

      Tantalum    gadolinium    samarium      yttrium   ytterbium

       Lutetium    praseodymium   holmium     erbium   thulium     dysprosium

       terbium   europium  lanthanum   cerium   neodymium  scandium 

         rubidium    cesium