Effects of short-term exposure to particulate matter on emergency department admission and hospitalization for asthma exacerbations in Brescia district

Abstract

Background

Rising pollution plays a crucial role in worsening several respiratory diseases. Particulate Matter (PM)-induced asthma exacerbations are one of the most dangerous events.

Objectives

To assess the correlation between progressive particulate matter short-term exposure and asthma exacerbations, we investigated the role of PM levels on Emergency Department (ED) admissions and hospitalizations for these events in Brescia, an important industrial city located in northern Italy with high yearly levels of air pollution.

Methods

We analyzed 1050 clinical records of ED admissions for suspected asthma exacerbation, starting from January 2014 to December 2017. Daily PM levels were collected from the Environmental Protection Regional Agency. We performed a time-series analysis using a Poisson regression model with single and multiple day-lag. Results were expressed as Relative Risk (RR) and Excess of Relative Risk (ERR) of severe asthma exacerbation over a 10 µg/m³ increase in PM10 and PM2.5 concentration.

Results

We selected and focused our analysis on 543 admissions for indisputable asthma exacerbation in ED and hospital. The time-series study showed an increase of the RR (CI95%) for asthma exacerbation-related ED admissions of 1.24 with an ERR of 24.2% for PM2.5 at lag0–1 (p < 0.05). We also estimated for PM2.5 a RR (CI95%) of 1.12 with an ERR of 12.5% at lag0–5 (p ≤ 0.05). Again, for PM2.5, an increase of the RR (CI95%) for asthma exacerbation-related hospitalizations of 1.31 with an ERR of 30.7% at lag0–1 (p < 0.05) has been documented. These findings were confirmed and even reinforced considering only the population living in the city.

Conclusions

Short-term PM exposure, especially for PM2.5, plays a critical role in inducing asthma exacerbation events leading to ED admission or hospitalization.

Keywords:

• Particulate matter
• asthma
• PM10
• PM2.5
• emergency department
• hospitalization
• airborne pollutants
• asthma exacerbation

Authors contribution

Study design: LP. Data collection: JG and CC. Data analysis: EZ and JG. Interpretation of results: All authors. Initial draft: LP. Manuscript revision: All authors.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.