Urinary heavy metals, phthalates, perchlorate, nitrate, thiocyanate, hydrocarbons, and polyfluorinated compounds are associated with adult hearing disturbance: USA NHANES, 2011–2012.

BACKGROUND: Links between environmental chemicals and human health have emerged, but the effects on hearing were less studied. Therefore, the aim of the present study was to investigate the relationships of different sets of environmental chemicals and the hearing conditions in a national and population-based setting.

METHODS: Data was retrieved from the US National Health and Nutrition Examination Surveys, 2011-2012 including demographics, serum measurements, lifestyle factors, self-reported hearing conditions, and urinary environmental chemical concentrations. Chi-square test, t test, and survey-weighted logistic regression models were performed.

RESULTS: Among the American adults aged 20-69 (n=5560), 462 (8.3 %) people reported their hearing condition as moderate trouble to deaf. They had higher levels of urinary hydrocarbons and polyfluorinated compounds but not heavy metals, phthalates, arsenic, pesticides, phenols, parabens, perchlorate, nitrate, and thiocyanate concentrations. Also, 466 (10.0 %) people had hearing difficulties during conversation. They had higher levels of urinary cobalt (odds ratio (OR) 1.27, 95 % confidence interval (95%CI) 1.00-1.63), molybdemum (OR 1.45, 95%CI 1.04-2.02), strontium (OR 1.56, 95%CI 1.10-2.21), phthalates, perchlorate (OR 1.27, 95%CI 1.05-1.54), nitrate (OR 1.60, 1.03-2.49) and thiocyanate (OR 1.22, 95%CI 1.01-1.48) concentrations but not arsenic, pesticides, phenols, parabens, hydrocarbons, and polyfluorinated compounds. Moreover, people who reported difficulties in following conversation with background noise had higher levels of urinary tin concentrations (OR 1.17, 1.00-1.36).

CONCLUSIONS: Urinary heavy metals, phthalates, perchlorate, nitrate, thiocyanate, hydrocarbons, and polyfluorinated compounds were associated with the adult hearing disturbance, although the causality cannot be established. Elimination of these environmental chemicals might need to be considered in future environmental health policy and health intervention programs.