Human nails as a biomarker of arsenic exposure from well water in Inner Mongolia: comparing atomic fluorescence spectrometry and neutron activation analysis

Abstract

Arsenic (As) is found naturally in the geological strata within the Ba Men Region of Inner Mongolia, China. A study was conducted to compare the total As measurements from two analytical techniques: instrumental neutron activation analysis (INAA) and atomic fluorescence spectrometry (AFS), and to verify nails as an exposure biomarker in this population. In 1999, nail and water samples were collected in a pilot study. Fingernails and toenails were pooled from 32 participants and analysed for total As by both INAA and AFS. Mean nail As values were 14.8±2.4 and 19.4±2.8 µg g⁻¹ (±SEM) for INAA and AFS, respectively. Results from these two methods were significantly correlated (r=0.93, p<0.0001). In 2000, a second study was conducted and INAA was used to measure total As in toenails from 314 Ba Men residents. Well water samples were collected from 121 households and analysed by AFS. A significant correlation was observed between toenail and well water As (r=0.84, p<0.0001). Based on the results, INAA was significantly correlated with AFS and proved to be a reliable measure of nail As levels. In this population, toenail samples are a useful internal As exposure biomarker from drinking water sources.

Keywords: :

• Arsenic
• nails
• drinking water
• neutron activation
• analysis
• atomic fluorescence spectrometry

Acknowledgements

The authors thank the administrators and staff members of the Inner Mongolia Center for Endemic Disease Control and Research and the Ba Men Anti-epidemic Station, Inner Mongolia, China, for administrative support and sample collection. Special thanks to Scott Lassell, Nuclear Services Manager, Nuclear Services Department, North Carolina State University, and to Dr Reeder Sams for reviewing the manuscript. The research described here was reviewed by the National Health and Environmental Effects Research Laboratory, US Environmental Protection Agency, and approved for publication. Approval does not signify that the contents necessarily reflect the views and policies of the agency, nor does the mention of trade names or commercial products constitute endorsement or recommendation for use.