There is no information on the association between oral exposure to arsenic (As) and hearing loss in humans or mice. In this combined epidemiological study and experimental study, the association of oral exposure to As with hearing loss in people aged 12-29 years and young mice was examined. Subjects in the exposure group (n?=?48), who were drinking tube well water contaminated with As, showed significantly higher risks of hearing loss at 4?kHz [odds ratio (OR)?=?7.60; 95% confidence interval (CI): 1.56, 57.88], 8?kHz (OR?=?5.00; 95% CI: 1.48, 18.90) and 12?kHz (OR?=?8.72; 95% CI: 2.09, 47.77) than did subjects in the control group (n?=?29). The authors then performed an experiment in which young mice were exposed to As via drinking water at 22.5?mg/L, which is a much greater concentration than that in human studies. The exposure group showed hearing loss and accumulation of As in inner ears. Ex vivo exposure of the organ of Corti from mice exposed to As significantly decreased the number of auditory neurons and fibres. The authors concluded that the combined study showed that oral exposure to As caused hearing loss in young people and young mice.
Full Source: Li X, Ohgami N, Omata Y, Yajima I, Iida M, Oshino R, Ohnuma S, Ahsan N, Akhand AA, Kato M. ; Full Source: Science Reports. 2017 Jul 28;7(1):6844. doi: 10.1038/s41598-017-06096-0.