Air pollution increases the risk of SSNHL: A nested case-control study using meteorological data and national sample cohort data

Hyo Geun Choi,So Young Kim,Chanyang Min

doi:10.1038/s41598-019-44618-0

Abstract

This study aimed to evaluate the impact of weather conditions and air pollution on the onset of sudden sensorineural hearing loss (SSNHL). The Korean Health Insurance Review and Assessment Service - National Sample Cohort (HIRA-NSC) from 2002 through 2013 was used. A total of 5,200 participants with SSNHL were matched 1:4 for age, sex, income, region of residence, hypertension, diabetes, and dyslipidemia with 20,800 control participants. Meteorological data included daily mean temperature (°C), daily highest temperature (°C), daily lowest temperature (°C), daily temperature difference (°C), relative humidity (%), ambient atmospheric pressure (hPa), pressure, SO2 (ppm), NO2 (ppm), O3 (ppm), CO (ppm), and PM10 (μg/m3) of a mean of 60 days, 30 days, 14 days, 7 days, and 3 days before SSNHL were analyzed. Hourly measurements were taken from 94 places to assess the temperature, humidity, and atmospheric pressure and from 273 places to determine SO2, NO2, O3, CO, and PM10. Crude and adjusted odds ratios (ORs) and 95% confidence intervals (CIs) of meteorological data for SSNHL were analyzed using unconditional logistic regression analyses. Subgroup analyses were conducted by age and sex. The mean NO2 and O3 concentrations 14 days before the index date were different in the SSNHL group compared to those in the control group (P < 0.001 for NO2 and P = 0.021 for O3). The adjusted 14-day OR for NO2 (0.1 ppm) exposure was 3.12 in the SSNHL group compared to that in the control group (95% CI = 2.16–4.49, P < 0.001). The increased odds of NO2 exposure for 14 days in the SSNHL group persisted in the age group older than 30 years for both sexes. Other meteorological conditions did not show differences between the SSNHL and control groups. SSNHL was associated with high concentrations of NO2.

Highlights

Industrialization has contributed to increasing health and economic burdens from air pollution[1]
Sex, income level, region of residence, and past medical histories of hypertension, diabetes, and dyslipidemia were precisely matched between the sensorineural hearing loss (SSNHL) and control groups
We described the mean of meteorological and air pollution measurements for 14 days before the index date

Summary

Introduction

Industrialization has contributed to increasing health and economic burdens from air pollution[1]. Air pollutants, including particulate matter (PM), nitrogen oxide (NO2), and ozone (O3), impact extrapulmonary and pulmonary systems[2] Cardiovascular disorders, such as acute myocardial infarction and stroke, are linked to increased levels of air pollutants[3,4,5,6]. A retrospective study of hospital patients reported that, of the different meteorological conditions, the onset of SSNHI was associated only with strong wind speeds for 7 days[12] Another retrospective study described no significant relationship between the onset of SSNHL and any meteorological conditions, including temperature and atmospheric pressure[13]. The present study hypothesized that meteorological conditions (including air pollution) can influence the onset of SSNHL. Differences in meteorological conditions were analyzed between the SSNHL and the control group

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Conclusion