Association between Chronic Laryngitis and Particulate Matter Based on the Korea National Health and Nutrition Examination Survey 2008–2012

BACKGROUND Chronic laryngitis (CL) has been described as chronic inflammation of the larynx. CL have various causes such as long-term smoking, acid reflux, voice overuse, bronchitis, allergies, pneumonia, excessive exposure to toxic chemicals and complications from the flu or a chronic cold. However, the prevalence of CL and role of air pollution in the etiology is uncertain. OBJECTIVE The aim of this study was to investigate the relationship between CL and particulate matter with aerodynamic diameter less than 10 μm (PM10) in South Korea using data from the Korea National Health and Nutrition Examination Surveys (KNHANES) during 2008-2012. METHODS KNHANES is a cross-sectional survey of the civilian, non-institutionalized population of South Korea (n = 21,116). A field survey team that included an otolaryngologist moved with a mobile examination unit and performed interviews and physical examinations. The mean annual concentrations of ambient PM10, SO2, O3, NO2, and CO levels in Korea were determined from monitoring station data. Multiple logistic regression was used to examine the relationship of air pollution to CL. RESULTS Among the population ≥ 19 years of age, the weighted prevalence of CL was 3.37 ± 0.30% (95% confidence interval, 2.79-3.95%). CL was more prevalent in men, current smokers, and those with lower household income and prevalence increased with age. A significant decrease over time was observed in the prevalence of CL (P for trend = 0.0049) and the annual average concentrations of PM10 (P for trend < 0.0001) from 2008 to 2012. In a multivariate model, the factors associated with CL included PM10 (odds ratio [OR], 1.378, p = 0.0457), age (OR, 1.020, p<0.0001), sex (OR, 0.734, p = 0.0179), and smoking status (OR, 1.438, p = 0.0054). CONCLUSION Elevated PM10 exposures could be associated with increased risk of CL in South Koreans. Further epidemiological and experimental studies are necessary to clarify the impact of chronic PM10 exposure on CL.