Short-term effects of low-level PM2.5, PM10, O3, and tropical meteorological conditions on emergency department visits for respiratory diseases in Haikou, China

To assess the correlation between atmospheric pollutants, meteorological factors, and emergency department visits for respiratory diseases in Haikou City. Daily data on atmospheric pollutants, meteorological factors, and emergency department visits for respiratory diseases in Haikou City from 2018 to 2021 were collected. The Spearman rank correlation test was used to analyze the correlation, and a distributed lag non-linear model was employed to analyze the health effects and lag impacts of environmental factors. Subgroup analyses were conducted based on sex and age. According to the criteria of International Classification of Diseases (ICD-10: J00-J99), a total of 221 913 cases were included, accounting for 21.3% of the total emergency department visits in Haikou City. For every 1 °C increase in temperature, the risk of emergency department visits increased by 1.029% (95% CI 1.016%-1.042%). Relative humidity greater than 80% reduced the risk of visits, while higher atmospheric pressure (>1 010 hpa) also decreased the likelihood of daily emergency department visits. Higher concentrations of PM25 (30-50 μg/m3), PM10 (>60 μg/m3), and O3 (75-125 μg/m3) were associated with increased visits. Higher temperatures (>25 °C) have a greater impact on females and children aged 0-14 years, while males are more sensitive to low atmospheric pressure. Individuals aged 65 and above exhibited increased sensitivity to O3 concentration, and the effects of PM2.5, PM10, and O3 are more pronounced in individuals over 14 years old. Short-term exposure to high temperatures, particulate matter pollutants (PM25 and PM10), and ozone (O3) is associated with increased emergency department visits for respiratory diseases.