By a happy coincidence, the completion of this text coincided with the
200th anniversary of the discovery of gadolinite, the mineral with which
the lanthanide story begins. For a group of elements which occur in only
trace amounts biologically, and which have no known metabolic role, the
lanthanides have spawned a surprisingly large biochemicalliterature. Se-
rious interest in the biochemical properties ofthese elements can be
traced to concerns about the safety of radioactive lanthanides toward
the end of World War 11. As recent events at Chernobyl indicate, this
concern re- mains topical. However, the literature on lanthanide
biochemistry pre- dates the atomic era, beginning with sporadic,
medically motivated studies in the latter part of the 19th century. Much
of the present biochemical activity involving the lanthanides centers
around their ability to provide 2 important information on the
interactions of Ca + with macromolecules and with eukafyotic cells. With
the increasing industrial use of the lan- thanides, their toxicological
properties will need to be examined more closely. Rare earth
pneumonoconiosis has already been identified as a disease produced by
industrial exposure to lanthanides. Several of the biochemical
properties of the lanthanides are of relevance to modern medicine.
Already cerium-based ointments are used to treat burn wounds, while
paramagnetic lanthanides find application in nuclear magnetic res-
onance imaging. This book is an attempt to collate and to present in
reasonable detail existing knowledge of lanthanide biochemistry before
the literature be- comes unmanageable.