title: Biomonitoring of mercury, cadmium, and lead exposure in Japanese children: a cross-sectional study.
abstract: OBJECTIVE
  To measure current Hg, Cd, and Pb exposure in Japanese children, and to estimate dietary intakes of foods responsible for high body burden.
  
  
  METHODS
  Blood, hair, and urine samples were collected from 9 to 10-year-old 229 children in Asahikawa and measured for Hg, Cd, and Pb in these matrices. Diet history questionnaire was used to estimate intake of marine foods and other food items. Hg level was measured by cold vapor atomic absorption spectrometry. Cd and Pb levels were determined with inductively coupled plasma mass spectrometry.
  
  
  RESULTS
  Geometric mean (GM) of blood Hg, Cd, and Pb was 4.55 μg/L, 0.34 μg/L, and 0.96 μg/dL, respectively. Urinary Cd level was 0.34 μg/g creatinine (GM) and hair Hg was 1.31 μg/g (GM). Approximately one-third (35%) of blood samples had Hg level above the U.S. EPA reference dose (RfD; 5.8 μg/L). Hair Hg level exceeded U.S. EPA RfD (1.2 μg/g) in 59 % samples. Children in the upper quartile of blood Hg level had significantly higher intake of large predatory fish species compared to those in the lower quartile of blood Hg.
  
  
  CONCLUSIONS
  Those with high blood Hg level may be explained by more frequent intake of big predatory fish. Cd and Pb exposure is generally low among Japanese children. As no safety margin exists for Pb exposure and high exposure to MeHg is noted in Japanese population; periodic biomonitoring and potential health risk assessment should continue in high-risk populations, notably among children.
authors.affiliation: Department of Environmental and Preventive Medicine, Jichi Medical University School of Medicine, 3311-1 Yakushiji, Shimotsuke, Tochigi, 329-0498, Japan.
authors.forename: Cimi
authors.initials: C
authors.lastname: Ilmiawati
authors.forename: Takahiko
authors.initials: T
authors.lastname: Yoshida
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Itoh
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Nakagi
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Saijo
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Sugioka
authors.forename: Mineshi
authors.initials: M
authors.lastname: Sakamoto
authors.forename: Akihiko
authors.initials: A
authors.lastname: Ikegami
authors.forename: Masanori
authors.initials: M
authors.lastname: Ogawa
authors.forename: Fujio
authors.initials: F
authors.lastname: Kayama
mesh_terms: D015415:Biomarkers / Q000032:analysis*; D002104:Cadmium; D002648:Child; D003430:Cross-Sectional Studies; D004032:Diet; D004781:Environmental Exposure / Q000032:analysis*; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000032:analysis*; D005260:Female; D005506:Food Contamination / Q000032:analysis*; D006197:Hair / Q000737:chemistry; D006801:Humans; D007564:Japan; D007854:Lead; D008297:Male; D008628:Mercury; D019216:Metals, Heavy / Q000032:analysis* / Q000097:blood / Q000652:urine; D012044:Regression Analysis; D017747:Seafood; D011795:Surveys and Questionnaires
chemical_list: D015415:Biomarkers; D004785:Environmental Pollutants; D019216:Metals, Heavy; D002104:Cadmium; D007854:Lead; D008628:Mercury