title: A biological indicator of inorganic arsenic exposure using the sum of urinary inorganic arsenic and monomethylarsonic acid concentrations.
abstract: OBJECTIVE
  The sum of urinary inorganic arsenic (iAs), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) concentrations is used for the biological monitoring of occupational iAs exposure. Although DMA is a major metabolite of iAs, it is an inadequate index because high DMA levels are present in urine after seafood consumption. We estimated the urinary iAs+MMA concentration corresponding to iAs exposure.
  
  
  METHODS
  We used data from two arsenic speciation analyses of urine samples from 330 Bangladeshi with oral iAs exposure and 172 Japanese workers without occupational iAs exposure using high-performance liquid chromatography with inductively coupled plasma mass spectrometry.
  
  
  RESULTS
  iAs, MMA, and DMA, but not arsenobetaine (AsBe), were detected in the urine of the Bangladeshi subjects. The correlation between iAs+MMA+DMA and iAs+MMA was obtained as log (iAs+MMA) = 1.038 log (iAs+MMA+DMA) -0.658. Using the regression formula, the iAs+MMA value was calculated as 2.15 and 7.5 μg As/l, corresponding to 3 and 10 μg As/m(3) of exposures, respectively. In the urine of the Japanese workers, arsenic was mostly excreted as AsBe. We used the 95th percentile of iAs+MMA (12.6 μg As/l) as the background value. The sum of the calculated and background values can be used as a biological indicator of iAs exposure.
  
  
  CONCLUSIONS
  We propose 14.8 and 20.1 μg As/l of urinary iAs+MMA as the biological indicators of 3 and 10 μg As/m(3) iAs exposure, respectively.
authors.affiliation: Department of Medical Risk Management, Graduate School of Risk and Crisis Management, Chiba Institute of Science.
authors.forename: Akihisa
authors.initials: A
authors.lastname: Hata
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Kurosawa
authors.forename: Yoko
authors.initials: Y
authors.lastname: Endo
authors.forename: Kenzo
authors.initials: K
authors.lastname: Yamanaka
authors.forename: Noboru
authors.initials: N
authors.lastname: Fujitani
authors.forename: Ginji
authors.initials: G
authors.lastname: Endo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001151:Arsenic / Q000652:urine*; D001152:Arsenicals / Q000652:urine*; D001459:Bangladesh; D015415:Biomarkers / Q000652:urine; D002851:Chromatography, High Pressure Liquid; D004781:Environmental Exposure / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods*; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D013058:Mass Spectrometry; D008875:Middle Aged; D016273:Occupational Exposure / Q000032:analysis*; D055815:Young Adult
chemical_list: D001152:Arsenicals; D015415:Biomarkers; C020300:monomethylarsonic acid; D001151:Arsenic