Effects on Morbidity and Mortality of Critical Episodes of PM2.5 in the City of Medellin, 2015

Abstract

Two critical episodes of PM2.5 were observed in Medellin (level over 75 mg/m3 for three days or more) on March 15-18 and March 25-28, 2015. The association between acute exposure to PM2.5 during episodes and daily cases of mortality and morbidity and emergency room visits in population under 5 years and adults aged 65 and over was examined in the quarter between February and April 2015. Statistical analyzes of interrupted time series and generalized additive models of Poisson regression were performed.During the episodes, the increase of 10 mg/m3 in the daily average of PM2.5 was associated with the increase of 4.6% and 6.1% in emergency room visits of children under 5 years of age due to respiratory infection and pneumonia in the same day of the increase, and variations of 6.2% and 4.6% for the cumulative exposure of seven days, respectively. For this age group increases in 3.3% for incident cases of respiratory infection and 5.5% for pneumonia were reported in the same day of exposure and in 6.7% in the distributed delay of 0-7 for both.For all ages and adults 65 and older, the cumulative effects of mortality from respiratory caused increased 2.4% and 4.5%, respectively, per 10 mg/m3 in the daily average of PM2.5 after 7-day exposure.Compared with the days of the February-April quarter in which the atmospheric episode did not appear on the days of critical episodes, children under 5 years of age presented an excess of 39.4% in emergency room visits due to pneumonia and 22.7% due to respiratory infection. In the same age group, incident cases of pneumonia and respiratory infection increased by 20.9% and 16.15%, respectively, there was also an excess of 13.2% in the asthma crisis.This study report excesses of morbidity and emergency room visits in children under 5 years old during critical episodes in Medellin.