Infant morbidity caused by respiratory diseases and its relation with the air pollution in Juarez City, Chihuahua, Mexico]

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 respiratory diseases, and c) asthma attacks. This information was stratified by age group (< = 5 years and > 5 years). Daily air pollution data (ozone and PM10) and weather conditions were obtained from the Monitoring Network System in Juarez City. Statistical analysis was carried out using a Generalized-Additive Model assuming a Poisson distribution. Results: Ozone concentrations, but not PM10, were statistically associated with emergency room visits for respiratory diseases, mainly among children 5 years old or younger. In this group, an increase of 20 ppb I-hr maximum for ozone was associated with an increase of 8.3% in the number of emergency 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 the group 6 to 16 years of age was observed for 3-day lag (5.1% for an increase of 20 ppb I-hr maximum for ozone). For the 6 to 16 year old group we did not find a significant effect. Conclusion:The wide range of risk is quite important and might represent a substantial cost for the health system as well as for the society. Our results emphasize the need to implement preventive and control measures for air pollution and avoid the worsening of the present situation.