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Yttrium [Y, 39]
Mechanisms of its toxicity may include enzyme inhibition, indirect effects
(i.e., binding to cofactors, vitamins, and substrates), and substitution for essential
metals, which result in its imbalance (Horovitz 2000). Water-soluble compounds
of Y are considered mildly toxic, whereas its insoluble compounds are nontoxic
(Emsley 2011).
90 Yttrium is one of the most useful radioisotopes in the development of antibodybased radioimmunotherapy. The evaluation of the pharmacokinetic profile for 90 Y
radiopharmaceuticals is usually performed by radiochemical methods (Ciavardelli
et al. 2007). The radioactive isotope 90 Y is used in drugs for the treatment of various cancers, including leukemia, lymphoma, and bone cancer (Emsley 2011). It can
also be a threat to the liver, when it accumulates in the human body. It is mostly
dangerous in the working environment, due to the fact that damps and gasses can
be inhaled with air. This can cause lung embolisms, especially during long-term
exposure. Yttrium can also cause cancer in humans, especially lung cancer, when it
is inhaled. However, it is not yet classified by the International Agency for Research
on Cancer.
The mean quantity of Y ingested by preschool children in Amherst, Massachusetts,
was 2.09 μg/day (Stanek et al. 1988). Its ingestion with food has been estimated to
be ranged from 3 to 5 μg/day in Japanese adult males (Shiraishi et al. vide Stanek
et al. 1988).