# The association between pulmonary tuberculosis recurrence and exposure to fine particulate matter and residential greenness: A population-based retrospective study

## TL;DR

This study found that higher exposure to fine particulate matter increases the risk of pulmonary tuberculosis recurrence, while residential greenness may protect against it.

## Contribution

The study identifies a novel interaction between PM2.5 exposure and residential greenness in influencing PTB recurrence.

## Key findings

- Higher PM2.5 exposure is linked to increased PTB recurrence risk.
- Residential greenness is negatively associated with PTB recurrence.
- An interaction exists between PM2.5 and greenness in affecting recurrence risk.

## Abstract

To assess the association of pulmonary tuberculosis (PTB) recurrence with fine particulate matter (PM2.5) and residential greenness using a population-based retrospective study design.

All incident PTB patients, registered in Tuberculosis Information Management System (TBIMS) from 2015 to 2019 in Quzhou City, China, were included. The data on PM2.5 exposure was extracted from the China High Air Pollutants dataset and the level of greenness was estimated using the Normalized Difference Vegetation Index (NDVI) values around the patient's residence. The Cox proportional hazards models were used to quantify the risk of PTB recurrence.

6732 Eligible PTB incident patients were included in the study with a mean age of 56.86 years and a median follow-up time of 750 days. Recurrence was observed in 554 patients (8.2 %). Exposure to NDVI was observed to be negatively associated with PTB recurrence (HR: 0.86, 95 % CI: 0.75–0.98 per 0.1-unit increase). The strength of the association between higher PM2.5 and the risk of PTB recurrence was greater than that of lower PM2.5 concentrations in both low and high NDVI groups (HR:6.62 and 4.35, p-interaction <0.001).

Our findings suggest that higher PM2.5 exposure might increase the risk of PTB recurrence, while residential greenness might have a protective effect. Like other chronic respiratory diseases, prevention and control of PTB will also benefit from comprehensive environmental management.

•Exposure of fine particulate matter increases pulmonary tuberculosis recurrence risk.•Residential greenness negatively relates to pulmonary tuberculosis recurrence.•Interaction might exist between residential greenness and fine particulate matter.

Exposure of fine particulate matter increases pulmonary tuberculosis recurrence risk.

Residential greenness negatively relates to pulmonary tuberculosis recurrence.

Interaction might exist between residential greenness and fine particulate matter.