Correlation over Time of Toenail Metals Among Participants in the VA Normative Aging Study from 1992 to 2014

Details

• Personal Author:
  Allen JG ; Amarasiriwardena C ; Coull B ; Schwartz J ; Sparrow D ; Vokonas P ; Weisskopf MG ; Wu AC
• Description:
  Background: Scientists use biomarkers to evaluate metal exposures. One biomarker, toenails, is easily obtained and minimally invasive, but less commonly used as a biomarker of exposure. Their utility will depend on understanding characteristics of their variation in a population over time. The objective of our study is to describe the correlation of toenail metal levels many years apart among participants in the VA Normative Aging Study (NAS). Methods: Toenail clippings from 825 participants of the NAS from year 1992 to 2014 were analyzed for lead (Pb), Arsenic (As), Cadmium (Cd), Manganese (Mn), and Mercury (Hg). We utilized linear mixed models to assess correlation between toenail metal concentrations in multiple toenail samples from the same subject collected years apart and identified the optimal covariance pattern by likelihood ratio tests and Akaike's information criterion (AIC). Correlations among different metals were described using Spearman correlations. Results: The average number of times toenail samples were collected from each subject ranged from 1.63 (Hg) to 2.04 (As). The average number of years between toenails collected per subject ranged from 4.73 (SD=2.44) (Mn) to 5.35 (SD=2.69) (Hg). Metal concentrations had slightly different correlation patterns over time, although for all metals correlations decreased with increasing time between samples. Estimated correlations over a 3-year span were highest for toenail Pb (0.68) and Hg (0.67), while As, Cd, and Mn had lower correlations of 0.49, 0.44, and 0.47, respectively. Even across a 6-year span, the lowest correlation was 0.35 (Cd). Conclusions: Our results suggest that Pb, As, Cd, Mn, and Hg levels from toenail clippings can reasonably reflect exposures over several years in elderly men in the NAS. Even across 6 years, toenail metal levels were generally well correlated among NAS participants. As such, they may be useful as biomarkers of exposure in epidemiological studies of similar populations. [Description provided by NIOSH]
• Subjects:
  Arsenic Biomarkers Cadmium Epidemiology Inorganic Chemicals Lead Manganese Mercury Metals Occupational Health Safety

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• Keywords:
  Exposure Assessment
• ISSN:
  1559-0631
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Massachusetts ; New York ; OSHA Region 1 ; OSHA Region 2
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  29
• Issue:
  5
• NIOSHTIC Number:
  nn:20056461
• Citation:
  J Expo Sci Environ Epidemiol 2019 Sep; 29(5):663-673
• Contact Point Address:
  Marc G. Weisskopf, Department of Environmental Health, Harvard T.H. Chan School of Public Health, 401 Park Drive, Landmark Center, L3-046, PO Box 15677, Boston, MA 02215, USA
• Email:
  mweissko@hsph.harvard.edu
• CAS Registry Number:
  Arsenic (CAS RN 7440-38-2) ; Cadmium (CAS RN 7440-43-9) ; Lead (CAS RN 7439-92-1) ; Manganese (CAS RN 7439-96-5) ; Mercury (CAS RN 7439-97-6)
• Federal Fiscal Year:
  2019
• Performing Organization:
  Harvard School of Public Health
• Peer Reviewed:
  True
• Start Date:
  20050701
• Source Full Name:
  Journal of Exposure Science and Environmental Epidemiology
• End Date:
  20280630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:d5ab3e3c1542a4bc573c82fc4773dcb6c7daf31f10df7a229baf4f5c9c9083354d3a451c990bde00b9633b7a9dd29dbcff0fde3f03b25d0b6995f067441b406d
• Download URL:
  https://stacks.cdc.gov/view/cdc/214066/cdc_214066_DS1.pdf
• File Type:
  [PDF - 697.22 KB ]