Association Between Exposure to Ozone (O₃) and the Short-Term Effect on Tuberculosis Outpatient Visits: A Time-Series Study in 16 Cities of Anhui Province, China

Abstract

Introduction

Evidence has shown that air pollutant exposure plays a vital role in the progression of tuberculosis (TB). The aim of this research was to assess the short-term effects of ozone (O₃) exposure and TB outpatient visits in 16 prefecture-level cities of Anhui, China, 2015–2020.

Methods

Distributed lag nonlinear model (DLNM), Poisson generalized linear regression model and random effects model were applied in this study. The effects of different age and gender on TB were investigated by stratified analysis, and then we performed sensitivity analyses to verify the stability of the results.

Results

A total of 186,623 active TB cases were registered from January 1, 2015 to December 31,2020 in Anhui. The average concentration of ozone is 92.77 ± 42.95 μg/m³. The maximum lag-specific and cumulative relative risk (RR) of TB outpatient visits was 1.0240 (95% CI: 1.0170–1.0310, lag 28 days) for each 10 µg/m³ increase in O₃ in the single-pollutant model. Estimation for 16 prefecture-level cities indicated that the strong association between O₃ and the risk of TB outpatient visits was in tongling (RR = 1.0555, 95% CI: 1.0089–1.1042), Suzhou (RR = 1.0475, 95% CI: 1.0268–1.0687), wuhu (RR = 1.0358, 95% CI: 1.0023–1.0704). Stratified analysis showed that the health effects of ozone exposure remained significant in male and older adults, and there was no significant association between exposure to ozone in children and adolescents and the risk of tuberculosis.

Discussion

We found that ozone exposure increases the risk of TB infection in outpatient patients, with males and the elderly being more susceptible, and it is necessary for government departments to develop targeted publicity and prevention measures in response to the local air quality conditions.

Keywords:

• air pollution
• ozone
• tuberculosis
• distributed lag nonlinear model
• Poisson generalized linear regression model

Data Sharing Statement

The data are not publicly available owing to privacy or ethical restrictions, as they contain sensitive information. The data are held by the Anhui Chest Hospital (Anhui Provincial Tuberculosis Institute). Requests to access the data can be sent to Xiaohong Kan ([email protected]), Chief of Scientific Research and Education at the Anhui Chest Hospital (Anhui Provincial Tuberculosis Institute).

Ethics Approval

The study was conducted in accordance with the Declaration of Helsinki and was approved by the Ethics Committee of Anhui Chest Hospital (K2020-011). Personal information of patients did not appear in this study; thus, informed consent was waived by the Ethics Committee of Anhui Chest Hospital.

Informed Consent Statement

Personal information of patients did not appear in this study; thus, informed consent was not needed.

Disclosure

The authors report no competing interests in this work.

Additional information

Funding

This study was supported by grants from National Key Project for infectious Disease of China (2018ZX10722301-001-004) and Key medical and health specialty construction project of Anhui Province. The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.