Arsenic level in toenails is associated with hearing loss in humans

Xiang Li; Nobutaka Ohgami; Ichiro Yajima; Huadong Xu; Machiko Iida; Reina Oshino; Hiromasa Ninomiya; Dandan Shen; Nazmul Ahsan; Anwarul Azim Akhand; Masashi Kato

doi:10.1371/journal.pone.0198743

Arsenic level in toenails is associated with hearing loss in humans

PLoS One. 2018 Jul 5;13(7):e0198743. doi: 10.1371/journal.pone.0198743. eCollection 2018.

Authors

Xiang Li¹, Nobutaka Ohgami^{1

2}, Ichiro Yajima^{1

2}, Huadong Xu¹, Machiko Iida^{1

2}, Reina Oshino^{1

2}, Hiromasa Ninomiya^{1

2}, Dandan Shen¹, Nazmul Ahsan^{2

3}, Anwarul Azim Akhand^{2

3}, Masashi Kato^{1

2}

Affiliations

¹ Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya, Japan.
² Voluntary Body for International Health Care in Universities, Nagoya, Japan.
³ Department of Genetic Engineering and Biotechnology, University of Dhaka, Bangladesh.

Abstract

Arsenic (As) pollution in drinking water is a worldwide health risk for humans. We previously showed hearing loss in young people who live in areas of As-polluted drinking water and in young mice orally treated with As. In this study, we epidemiologically examined associations between As levels in toenails and hearing in 145 Bangladeshi aged 12-55 years in 2014. Levels of As in toenails, but not those in urine, were shown to be significantly correlated with hearing loss at 4 kHz [odds ratio (OR) = 4.27; 95% confidence interval (CI): 1.51, 12.05], 8 kHz (OR = 3.91; 95% CI: 1.47, 10.38) and 12 kHz (OR = 4.15; 95% CI: 1.55, 11.09) by multivariate analysis with adjustments for age, sex, smoking and BMI. Our experimental study further showed a significant association between As levels in inner ears and nails (r = 0.8113, p = 0.0014) in mice orally exposed to As, suggesting that As level in nails is a suitable index to assess As level in inner ears. Taken together, the results of our study suggest that As level in nails could be a convenient and non-invasive biomarker for As-mediated hearing loss in humans.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adolescent
Adult
Animals
Arsenic / adverse effects
Arsenic / chemistry
Arsenic / isolation & purification*
Bangladesh / epidemiology
Child
Drinking Water / chemistry
Ear, Inner / chemistry
Ear, Inner / pathology
Environmental Exposure
Female
Hearing Loss / chemically induced
Hearing Loss / epidemiology
Hearing Loss / pathology*
Humans
Male
Mice
Middle Aged
Multivariate Analysis
Nails / chemistry*
Water Pollutants, Chemical / chemistry
Water Pollutants, Chemical / isolation & purification*
Young Adult

Substances

Drinking Water
Water Pollutants, Chemical
Arsenic

Grants and funding

This study was supported in part by Grants-in-Aid for Scientific Research on Innovative Areas (24108002, 16H01639, 18H04975), Scientific Research (A) (15H01743 and 15H02588), (B) (16H02962, 17KT0033) and (C) (16K08343, 16K08440, 16K10152), Grant-in-Aid for Challenging Exploratory Research (26670525) from the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Foundation from Center for Advanced Medical and Clinical Research Nagoya University Hospital, Aichi Health Promotion Foundation, the Mitsubishi Foundation, AEON Environmental Foundation, Nagono Medical Foundation, Grant for Environmental Research Projects from the Sumitomo Foundation (163119) and The Salt Science Research Foundation. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.