title: Effects of urban air pollutants on emergency visits for childhood asthma in Mexico City.
abstract: The metropolitan area of Mexico City, Mexico, has serious air pollution problems. Although air contaminants may contribute to clinical asthma, there are at present no data on the relation between air pollution exposure and childhood asthma in Mexico City. The authors reviewed data on emergency visits from January to June 1990 at one major pediatric hospital in Mexico City. They used a Poisson regression model to study the relation between the number of daily emergency visits for asthma and air pollutant levels. The levels of ozone and sulfur dioxide-exposure were significantly associated with the number of emergency visits for asthma. After adjustment for potential confounding factors, the multivariate regression model predicted that an increase of 50 ppb in the 1-hour maximum ozone level would lead to a 43% increase in the number of emergency visits for asthma on the following day. Exposure to high ozone levels (> 110 ppb) for 2 consecutive days increased the number of asthma-related emergency visits by 68 percent. The results of this study suggest that ozone exposure is positively associated with the number of children's emergency visits for asthma in Mexico City.
authors.affiliation: Centro Panamericano de Ecologia Humana y Salud, Organizacion Panamericana de la Salud, Mexico City.
authors.forename: I
authors.initials: I
authors.lastname: Romieu
authors.forename: F
authors.initials: F
authors.lastname: Meneses
authors.forename: J J
authors.initials: JJ
authors.lastname: Sienra-Monge
authors.forename: J
authors.initials: J
authors.lastname: Huerta
authors.forename: S
authors.initials: S
authors.lastname: Ruiz Velasco
authors.forename: M C
authors.initials: MC
authors.lastname: White
authors.forename: R A
authors.initials: RA
authors.lastname: Etzel
authors.forename: M
authors.initials: M
authors.lastname: Hernandez-Avila
mesh_terms: D000293:Adolescent; D000393:Air Pollutants / Q000009:adverse effects*; D001249:Asthma / Q000139:chemically induced* / Q000453:epidemiology; D001988:Bronchiolitis / Q000139:chemically induced* / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D016013:Likelihood Functions; D008297:Male; D008800:Mexico / Q000453:epidemiology; D010126:Ozone / Q000009:adverse effects / Q000032:analysis; D016012:Poisson Distribution; D013458:Sulfur Dioxide / Q000009:adverse effects / Q000032:analysis; D013997:Time Factors; D014505:Urban Population
chemical_list: D000393:Air Pollutants; D013458:Sulfur Dioxide; D010126:Ozone