(859) Mercury and Hearing Loss in Hispanic Children: NHANES 2017-2020 Analysis

Introduction: Despite reports of mercury ototoxicity, National Health and Nutrition Examination Survey (NHANES) studies have not identified a population-level association between mercury exposure and hearing loss. However, such associations may be more evident in at-risk groups with higher exposures. This study evaluates such an association for Hispanic children in the United States.

Methods: Children aged 6–19 years with audiometric testing from NHANES 2017-2020 were included. After exclusion for partial testing, hearing loss before age 1, and flat tympanograms, 2673 participants were analyzed.​ Hearing loss was defined as Pure-Tone Average >15 dB for low- or high-frequency hearing loss (LFHL: 0.5, 1.0, 2.0 kHz; HFHL: 3.0, 4.0, 6.0, 8.0 kHz), Pure-Tone Average (PTA: 0.5, 1.0, 2.0, 4.0 kHz), and any hearing loss (AHL). Pearson’s chi-squared and Wilcoxon rank-sum tests compared groups. Multivariate logistic regressions were run with hearing loss as the outcome, stratified by mercury level, age, sex, poverty-income ratio (PIR), past ear infection, health insurance, and health access.

Results: PIR (p=0.001), health access (p < 0.001), and health insurance (p < 0.001) were significantly different between Hispanic and non-Hispanic children, while percent with hearing loss and urine mercury levels were not. Among 111 Hispanic children with mercury measurements, higher urine mercury was significantly associated with LFHL (p=0.032), HFHL (p=0.010), PTA (p=0.009), and AHL (p=0.007). These associations were not significant in non-Hispanic children or the overall cohort.

Conclusions: Mercury exposure was associated with hearing loss in Hispanic children across all hearing loss categories, but not in other groups. This identifies an area of future study for preventing hearing loss and minimizing mercury exposure in at-risk groups.