Date Published: July 5, 2018
Publisher: Public Library of Science
Author(s): Xiang Li, Nobutaka Ohgami, Ichiro Yajima, Huadong Xu, Machiko Iida, Reina Oshino, Hiromasa Ninomiya, Dandan Shen, Nazmul Ahsan, Anwarul Azim Akhand, Masashi Kato, Jaymie Meliker.
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.
Exposure to arsenic (As) via drinking water is a health risk for humans [1–3]. Previous studies showed that exposure of humans to As was associated with cancer of the bladder, kidney, skin, prostate, lung and liver  and with cardiovascular disease . It was also shown that exposure to As was associated with neurological diseases including cognitive impairment in children [6, 7] and adults  and with diabetes mellitus [9–12].