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EVA study E misiones V ehiculares y A sma. Centers for Disease Control Air Pollution Respiratory Branch Instituto Nacional de Salud Pública Emory University School of Medicine Division of Pulmonary and Critical Care Medicine. Background.
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EVA studyEmisiones Vehiculares y Asma Centers for Disease Control Air Pollution Respiratory Branch Instituto Nacional de Salud Pública Emory University School of Medicine Division of Pulmonary and Critical Care Medicine
Background • In Ciudad Juarez 93% of the truck industry and 61.8% of the buses use diesel fuel • Outdated vehicular fleet • Vehicular sources: largest contributor to the emissions inventory • Ciudad Juarez – El Paso is one of the busiest land ports in the US borders (4th) • Trucks must circulate through the city before reaching the border
Environmental Health Perspectives. 108(7):A308-15, 2000 Jul.
Question • What are the health effects associated with traffic related emissions among asthmatic children in Ciudad Juarez? • Health effects associated with traffic related to the border crossing • Differential health effects in asthmatic and non-asthmatic children • Is exposure associated with airway inflammation? • Does atopy (allergic status) modify the risk?
Methods • Longitudinal study of school asthmatic and non-asthmatic children aged 6 –12 years from low to medium SES • Schools located in close proximity to main roads that contribute traffic flow to border crossings • Asthmatics: Medical diagnosis of asthma with at least two asthma-related ER visits in the last year (from IMSS) • Gender and age matched non-asthmatics: selected from same schools
n = 100 (50 asthmatics and 50 healthy) n = 100 (50 asthmatics and 50 healthy) Study Design 100 asthmatic children 100 healthy children 38Schools winter summer winter Follow-up for 16 weeks Follow-up for 16 weeks • Activities: • General questionnaire • Daily record • Medical/hospital visits • Exhaled NO (8 times) • Spirometry (8 times) • Exhaled Breath analysis x1 • Nasal lavage x 1 • Urine for PAH x 1 • Skin testing • Ambient data: • Local PM2.5 monitoring (48 h average) • Elemental Carbon (Quartz) • Passive samplers for NO2 monitoring (1 week) • Traffic counts • Geocoding of schools and houses • Meteorological data
Methods • Analysis • Mixed effects model, adjusting for age, gender, ETS, day of week, seasonality, school, BMI. • GIS variables • Road density, average traffic counts, distance to main roads • Buffers 50m, 100m, 200m, 300m • Exposure • School-level (air pollutants, GIS variables) • Subject or house-level (GIS variables)
Study population IDR: avg # of questionnaire positive responses/100 question-entries
13% 8% 1% Intermittent Mild persistent Moderate persistent Severe 78% Asthma Severity
Schools Houses
Air monitoring Results
Approx: 3904 Monitoring Days
Approx: 1807 Monitoring Days * Note that monitoring occurs generally in consecutive two-day periods and, therefore, appear in this plot to be two-week averages.
Levels of pollutants measured at participating schools in Ciudad Juarez, 2002 - 2003 ppb
Association between NO2 at schools and exhaled NO * β (± S.E.) : adjusted for age, sex, BMI, ETS, day of wk, and season * : p < 0.05
Association of exhaled NO with PM2.5, EC, and NO2 at schools PM2.5 EC NO2 PM2.5 EC NO2 β (± S.E.) : adjusted for age, sex, BMI, ETS, day of wk, and season * : p < 0.05
Road length exposure (<50m) • Length of road within 50 meters of a subject’s home was significantly associated with eNO levels in the asthmatics
Subject level length of road (all roads) within 50 meters against Log-eNO
Subject level roads within 50 meters by asthma/no-asthma status No asthma Asthma
Subject level length of roads in 100 m by asthma/no-asthma status No asthma Asthma
Association between the subject-level 50m buffer and exhaled NO * * β (± S.E.) : adjusted for age, sex, BMI, ETS, day of wk and season * : p < 0.05
Traffic counts within the 200m buffer and log-eNO by case/control status No asthma Asthma
Traffic counts within the 300m buffer and log-eNO by case/control status No asthma Asthma
Traffic counts within the 400m buffer and log-eNO by case/control status No asthma Asthma
Traffic counts within the 500m buffer and log-eNO by case/control status No asthma Asthma
Symptoms • Road length in the 50m buffer had a marginal significant association (p=0.06) with cough episodes in asthmatics, but not in non-asthmatics. • No significant associations with eNO and/or respiratory symptoms with distance to roads at schools
Conclusions • In ciudad Juarez, NO2 exposure in schools is associated with increased exhaled NO • Road-length (density) exposure within a 50 m buffer (home-level) is associated with increased exhaled NO and possibly cough only in asthmatics children • No significant associations with PM2.5, or EC
EPA Border 2012 US EPA4 97686501-0 USC, Department of Preventive Medicine Mike Jerret Kiros Berhane Zev Ross, Zev Ross Spatial Anlaysis. Salúd Publica, Cuernavaca Isabelle Romieu, Silvia Flores, Marlene Cortez. Rafael Santibañez, Mauricio Hernandez CDC, NCEH Stephen C. Redd, Allison Stock, Larry Needham, Andreas Sjodin, Mike Mcgeehin MIT & US Mexico foundation for the Science Mario Molina, Luisa Molina Environmental Defense Fund Carlos Rincón UACJ Rafael Granados and GIS lab team