Time-Dependent Relationship Between Particulate Matter Exposure and COPD Exacerbations

Abstract

Rationale This study aims to determine a relationship between short-term exposure to Particulate Matter and Fine Particulate Matter (PM10 and PM2.54) and the Emergency Department (ED) visit's trend for COPD Exacerbation. Visits' outcomes were also evaluated. The analysis has been conducted in Brescia, a city recognized for being one of the most important European industrial realities and one with the most complex environmental issues. Methods For this study, a dedicated database with data exclusively focused on COPD Exacerbation-related ED admissions has been created. Starting from January 1 st , 2014, to January 2016, 431 ED admission records for COPD Exacerbation have been collected. Data for the Particulate Matter daily mean concentrations were collected from the Environmental Protection Regional Agency (ARPA) and added to the database. Finally, a timeseries analysis with distributed day-lag has been conducted, and the results have been expressed in terms of Relative Risk (RR) and Relative Risk Increase (ER) for COPD Exacerbation-related ED visits and/or hospitalizations, over a 10µg/m3 increase in PM10 or PM2.5 concentration. Results A significant association for both PM10 and PM2.5 with the risk of ED visits and/or hospitalization for COPD Exacerbation. In lag0-1, increases of 10µg/m3 in PM10 concentration corresponded to a RR(IC95%) for ED visit of 1.06, while, for PM2.5, corresponded to 1.08 (p<0.05). At lag0-5, the RR(IC95%) corresponded to 1.06 and 1.09 for PM10 and PM2.5 respectively (p<0.05). Considering the hospitalizations, similar results have been found, with a RR of 1.07 and 1.10 in lag0-1; 1.07 and 1.11 in lag0-5. Conclusions Our findings increase the knowledge regarding the shortterm effects of exposure to Particulate Matter on the respiratory system. This study could also provide reliable data to monitor ED visits and outcomes over time.