A Korean study has found that long-term exposure to air pollution from environmental small particles (PM10), nitrogen dioxide, carbon monoxide and sulfur dioxide increases the risk of hearing loss. The study evaluated the associations between long-term exposure to air pollution and hearing loss in Korean adults.
More specifically, the study found that air pollution with ambient small particles (PM10) was significantly associated with the increased risk of a speech-frequency hearing loss and a high-frequency hearing loss. Air pollution with carbon monoxide (CO) was significantly associated with the increased risk of hearing loss at speech-frequency and high-frequency when air pollution was assessed at local level. Nitrogen dioxide (NO2) became significantly associated with hearing loss at speech-frequency. When air pollution was assessed at larger areas, small particles (PM10) and carbon dioxide (CO2) became stronger and sulfur dioxide (SO2) became a significant risk factor in hearing loss at speech frequency.
About the study
The study analysed data from 15,051 adults in the Korean National Health and Nutrition Examination Survey V (2010−2012). In the study, pure-tone average (PTA) of hearing thresholds at speech-frequency (0.5, 1, 2, 4kHz) and high-frequency (3, 4, 6kHz) were computed, and hearing loss was defined as more than 25dB in either ear. Ambient air pollutant concentrations for participants were collected for current-to-3 years prior to the audiometric examination.
The study, "Long-term exposure to ambient air pollutants and hearing loss in Korean adults", was published in the journal Science Direct.
Sources: https://pubmed.ncbi.nlm.nih.gov/ and the journal Science Direct