# Impacts of short-term exposure to ambient air pollutants on outpatient visits for respiratory diseases in children: a time series study in Yichang, China

## TL;DR

Short-term exposure to air pollution increases outpatient visits for respiratory diseases in children, according to a study in Yichang, China.

## Contribution

The study quantifies the hysteresis effects of multiple air pollutants on children's respiratory outpatient visits using a time series approach.

## Key findings

- All six pollutants showed a hysteresis impact on outpatient visits, with lags ranging from 4 to 6 days.
- O3 and CO were not significantly linked to chronic respiratory diseases in children.
- Infectious respiratory diseases showed similar patterns to overall respiratory diseases in response to air pollution.

## Abstract

There is growing evidence that the occurrence and severity of respiratory diseases in children are related to the concentration of air pollutants. Nonetheless, evidence regarding the association between short-term exposure to air pollution and outpatient visits for respiratory diseases in children remains limited. Outpatients cover a wide range of disease severity, including both severe and mild cases, some of which may need to be transferred to inpatient treatment. This study aimed to quantitatively evaluate the impact of short-term ambient air pollution exposure on outpatient visits for respiratory conditions in children.

This study employed data of the Second People’s Hospital of Yichang from January 1, 2016 to December 31, 2023, to conduct a time series analysis. The DLNM approach was integrated with a generalized additive model to examine the daily outpatient visits of pediatric patients with respiratory illnesses in hospital, alongside air pollution data obtained from monitoring stations. Adjustments were made for long-term trends, meteorological variables, and other influencing factors.

A nonlinear association was identified between PM2.5, PM10, O3, NO2, SO2, CO levels and the daily outpatient visits for respiratory diseases among children. All six pollutants exhibit a hysteresis impact, with varying durations ranging from 4 to 6 days. The risks associated with air pollutants differ across various categories of children’s respiratory diseases; notably, O3 and CO do not show statistical significance concerning the risk of chronic respiratory conditions. Furthermore, the results of infectious respiratory diseases were similar with those of respiratory diseases.

Our results indicated that short-term exposure to air pollutants may contribute to an increased incidence of outpatient visits for respiratory illnesses among children, and controlling air pollution is important to protect children’s health.

The online version contains supplementary material available at https://doi.org/10.1265/ehpm.24-00373.