title: Urinary monitoring of exposure to yttrium, scandium, and europium in male Wistar rats.
abstract: On the assumption that rare earth elements (REEs) are nontoxic, they are being utilized as replacements of toxic heavy metals in novel technological applications. However, REEs are not entirely innocuous, and their impact on health is still uncertain. In the past decade, our laboratory has studied the urinary excretion of REEs in male Wistar rats given chlorides of europium, scandium, and yttrium solutions by one-shot intraperitoneal injection or oral dose. The present paper describes three experiments for the suitability and appropriateness of a method to use urine for biological monitoring of exposure to these REEs. The concentrations of REEs were determined in cumulative urine samples taken at 0-24 h by inductively coupled plasma atomic emission spectroscopy, showing that the urinary excretion of REEs is <2 %. Rare earth elements form colloidal conjugates in the bloodstream, which make high REEs accumulation in the reticuloendothelial system and glomeruli and low urinary excretion. The high sensitivity of inductively coupled plasma-argon emission spectrometry analytical methods, with detection limits of <2 μg/L, makes urine a comprehensive assessment tool that reflects REE exposure. The analytical method and animal experimental model described in this study will be of great importance and encourage further discussion for future studies.
authors.affiliation: Department of Hygiene and Public Health I (Social and Environmental Health) and II (Community and Occupational Health), Division of Preventive and Social Medicine, Osaka Medical College, 2-7 Daigakumachi, Takatsuki City, Osaka, 569-8686, Japan. hyg043@art.osaka-med.ac.jp
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kitamura
authors.forename: Kan
authors.initials: K
authors.lastname: Usuda
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Shimizu
authors.forename: Keiichi
authors.initials: K
authors.lastname: Fujimoto
authors.forename: Rei
authors.initials: R
authors.lastname: Kono
authors.forename: Aiko
authors.initials: A
authors.lastname: Fujita
authors.forename: Koichi
authors.initials: K
authors.lastname: Kono
mesh_terms: D000284:Administration, Oral; D000818:Animals; D002712:Chlorides / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D004781:Environmental Exposure / Q000009:adverse effects; D004784:Environmental Monitoring / Q000379:methods*; D004785:Environmental Pollutants / Q000493:pharmacokinetics / Q000633:toxicity / Q000652:urine*; D005063:Europium / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000633:toxicity / Q000652:urine*; D007274:Injections, Intraperitoneal; D057230:Limit of Detection; D008297:Male; D008657:Metabolic Clearance Rate; D051381:Rats; D017208:Rats, Wistar; D015203:Reproducibility of Results; D012538:Scandium / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000633:toxicity / Q000652:urine*; D013054:Spectrophotometry, Atomic; D015019:Yttrium / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000633:toxicity / Q000652:urine*
chemical_list: D002712:Chlorides; D004785:Environmental Pollutants; C064782:yttrium chloride; D005063:Europium; C543902:scandium chloride; D015019:Yttrium; D012538:Scandium