Emergency department visits for Asthma Exacerbation after short-term exposure to Particulate Matter: trend assessment in a European industrial city.

Introduction: Rising pollution rates play a fundamental role in developing several respiratory diseases. Particulate Matter (PM)-induced Asthma Exacerbation is one of the most life-threatening events. In order to assess the correlation between progressive PM concentrations and Asthma Exacerbation events, we investigated the role of short-term PM exposure in the increase of Emergency Department (ED) visits for these events in Brescia, an important European industrial city, known for its high yearly levels of pollution. Methods: An analysis of 543 clinical records of ED admissions for Asthma Exacerbation, starting from January 2014 to December 2017, has been conducted. Daily PM levels were collected from the Environmental Protection Regional Agency (ARPA). We performed a time-series study using the Poisson regression model with single and multiple day-lag. Results were expressed as Relative Risk (RR) and Excess of Relative Risk (ER) of Asthma Exacerbation-related ED admissions, over a 10µg/m3 increase in PM10 and PM2.5 concentration. Results and Conclusions: The time-series study revealed an increase of the RR (CI95%) for Asthma Exacerbation-related ED visits of 1.24 with an ER of 24.15% for PM2.5 at lag0-1 (p<0.05). Interestingly for the same pollutant, we also documented a RR (CI95%) of 1.12 with an ER of 12.53% at lag0-5 (p≤0.05). Our analysis documented that short-term PM exposure acts a critical role in inducing Asthma Exacerbation events, especially PM2.5