Morbilidad infantil por causas respiratorias y su relación con la contaminación atmosférica en Ciudad Juárez, Chihuahua, México

Objective: To assess the impact of atmospheric pollutants on the respiratory health of children of different age groups in Juarez City, Chihuahua, Mexico. Material and Methods: Data on emergency room visits between 1997 and 2001 for respiratory diseases in children less than 17 years old were obtained from hospitals in the Juarez City belonging to the Mexican Social Security Institute (IMSS). Diseases were classified into three groups according to ICD 9th and 10th codes: a) upper respiratory diseases, b) lower respira- tory diseases, and c) asthma attacks. This information was stratified by age group (<=5 years and >5 years). Daily air pollution data (ozone and PM 10 ) and weather conditions were obtained from the Monitoring Network System in Jua- rez City. Statistical analysis was carried out using a General- ized Additive Model assuming a Poisson distribution. Results: Ozone concentrations, but not PM 10 , were statistically as- sociated with emergency room visits for respiratory dis- eases, mainly among children 5 years old or younger. In this group, an increase of 20 ppb 1-hr maximum for ozone was associated with an increase of 8.3% in the number of emer- gency room visits for upper respiratory diseases, with a 3- day exposure lag; and an increase of 12.7% in the number of emergency room visits for lower respiratory diseases when considering a 4-day exposure lag in a maximum 8-hr mobile average. The largest effect for the complete sample and for