Manganese exposure assessment - the use of toenails as a biomarker of exposure in US welders

Details

• Personal Author:
  Bainter J ; Dydak U ; Rosenthal F ; Snyder S ; Ward EJ
• Description:
  Previous studies have shown that high exposure to manganese (Mn) in occupational settings may lead to neurological health effects. Currently, there is no established biomarker for Mn exposure. The objective of this study was to evaluate the hypothesis that toenail Mn concentration is reflective of an individual's Mn exposure from occupational and dietary sources in a population of welders. Toenail clippings of all ten toes were collected from fifteen career welders and nineteen controls. The toenail samples were cleaned and sonicated in Triton X-100 surfactant, digested using microwave acid digestion and analyzed for Mn using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) for Mn. Respirable Mn exposure was estimated using a model combining air samples, work histories, and modifying factors such as ventilation and use of personal protective equipment. Dietary Mn and Fe were estimated with a food questionnaire. There was no significant difference between mean Mn concentration in right and left feet (4.89 vs. 4.27 ug/g, p = 0.1856). Toenail Mn levels were higher in welders than in controls (7.14 vs. 3.02 ug/g, p = 0.0003). Toenail Mn was significantly correlated with cumulative exposure to respirable Mn seven to twelve months prior to the toenail clipping date (r2 = 0.31, p = 0.03). When ratio of dietary intake of Mn to Fe, smoking, and age were included as covariates in the statistical model the correlation between respirable Mn exposure and toenail Mn improved (adjusted r2 = 0.56, p = 0.003). With two exceptions, toenail Mn was able to clearly distinguish exposed individuals from controls. The significant correlation of toenail Mn with the cumulative Mn exposure seven to twelve months prior to the toenail being clipped is consistent with the average growth time of toenails. The results suggest that toenail Mn is a valid, reproducible, easy to acquire biomarker of Mn exposure, which is feasible to use in an industrial welder population. [Description provided by NIOSH]
• Subjects:
  Biomarkers Environmental Exposure Environmental Monitoring Manganese Men Nervous System Nervous System Diseases Occupational Health Personal Protective Equipment Safety Surveys And Questionnaires Toxicology Ventilation Welding Women Workplace

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• Keywords:
  Air-samples Environmental-exposure Exposure-levels Food Humans Manganese-compounds Models Nervous-system Nervous-system-disorders Neurological-diseases Neurological-reactions Personal-protective-equipment Questionnaires Welders Work-environment Workers

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• ISSN:
  1096-6080
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Abstract or Summary
• Place as Subject:
  Arizona ; Indiana ; OSHA Region 5 ; OSHA Region 9
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  138
• Issue:
  1
• NIOSHTIC Number:
  nn:20043928
• Citation:
  Toxicologist 2014 Mar; 138(1):406
• CAS Registry Number:
  Manganese (CAS RN 7439-96-5)
• Federal Fiscal Year:
  2014
• Performing Organization:
  Purdue University, West Lafayette, Indiana
• Peer Reviewed:
  False
• Start Date:
  20010701
• Source Full Name:
  The Toxicologist. Society of Toxicology 53rd Annual Meeting and ToxExpo, March 23-27, 2014, Phonex, Arizona
• End Date:
  20270630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:f971fa984ab9ff9565840ace8d36861aad77328ea2933b096b8cf06bd95793404606cdd8dc62a92514d0fc457497c6905a37980f46cf16a8ca754a9e8dab5344
• Download URL:
  https://stacks.cdc.gov/view/cdc/199796/cdc_199796_DS1.pdf
• File Type:
  [PDF - 237.53 KB ]