Validation of in vivo toenail measurements of manganese and mercury using a portable x-ray fluorescence device

Details

• Alternative Title:
  J Expo Sci Environ Epidemiol
• Personal Author:
  Specht, Aaron J. ; Zhang, Xinxin ; Young, Anna ; Nguyen, Vy T. ; Christiani, David C. ; Ceballos, Diana M. ; Allen, Joseph G. ; Weuve, Jennifer ; Nie, Linda H. ; Weisskopf, Marc G.
• Description:
  Background and Objective:
  
  Toenail metal concentrations can be used as an effective biomarker for exposure to environmental toxicants. Typically toenail clippings are measured ex vivo using inductively-coupled plasma mass spectrometry (ICP-MS). X-ray fluorescence (XRF) toenail metal measurements done on intact toenails in vivo could be used as an alternative to alleviate some of the disadvantages of ICP-MS. In this study, we assessed the ability of using XRF to measure toenail metal concentrations in real time without having to clip the toenails (i.e. in vivo) in two occupational settings for exposure assessment of manganese and mercury.
  
  Materials and Methods:
  
  The portable XRF method used a 3-minute in vivo measurement of toenails prior to clipping and was assessed against ICP-MS measurement of toenail clippings taken immediately after the XRF measurement and work history for a group of welders (n=16) assessed for manganese exposure and nail salon workers (n=10) assessed for mercury exposure.
  
  Results and Conclusions:
  
  We identified that in vivo XRF metal measurements were able to discern exposure to manganese in welders and mercury in nail salon workers. We identified significant positive correlations between ICP-MS of clippings and in vivo XRF measures of both toenail manganese (R= 0.59, p=0.02) and mercury (R= 0.74, p<0.001), as well as between in vivo XRF toenail manganese and work history among the welders (R=0.55, p=0.03). We identified in vivo XRF detection limits to be 0.5 μg/g for mercury and 2.6 μg/g for manganese. Further work should elucidate differences in timing of exposure using the in vivo XRF method over toenail clippings and modification of measurement time and x-ray setting to further decrease the detection limit. In vivo portable XRF measurements can be used to effectively measure toenail Mn and Hg in occupational participants in real time during study visits and at a fraction of the cost.
  
  
• Subjects:
  Article Fluorescence Humans Manganese Mercury Metals Nails Spectrometry, X-Ray Emission X-Rays
• Source:
  J Expo Sci Environ Epidemiol. 32(3):427-433
• Pubmed ID:
  34211112
• Pubmed Central ID:
  PMC8720103
• Document Type:
  Journal Article
• Funding:
  P42 ES007373/ES/NIEHS NIH HHSUnited States/ ; P30 CA023108/CA/NCI NIH HHSUnited States/ ; T42OH008416/ACL/ACL HHSUnited States/ ; UL1 TR001102/TR/NCATS NIH HHSUnited States/ ; R25 ES023635/ES/NIEHS NIH HHSUnited States/ ; R21 ES024700/ES/NIEHS NIH HHSUnited States/ ; P30 ES000002/ES/NIEHS NIH HHSUnited States/ ; K01 OH011648/OH/NIOSH CDC HHSUnited States/
• Volume:
  32
• Issue:
  3
• NIOSHTIC Number:
  nn:20064895
• Collection(s):
  CDC Public Access National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:43df85a5a95885a55bb7db616da001fc822606d04785ce717b9146a9d4c523fc1d6dac433353fd5e6ec02b14233f79632f0b9dfc1098a5d28a27ef03c37a579d
• Download URL:
  https://stacks.cdc.gov/view/cdc/113047/cdc_113047_DS1.pdf
• File Type:
  [PDF - 680.38 KB ]