title: [Evaluation of the indoor and outdoor air quality in a nursery school in Mexico City].
abstract: OBJECTIVE
  To evaluate the differences between indoor and outdoor ozone (O3) and nitrogen dioxide (NO2) levels at a school located in southwest Mexico City.
  
  
  METHODS
  Indoor and outdoor O3 and NO2 levels were measured daily between January and April 1990 by manual monitoring.
  
  
  RESULTS
  Indoor and outdoor concentrations of nitrogen dioxide did not surpass the Mexican standard (0.21 ppm). The correlation coefficient between maximum NO2 concentrations measured by the city's local monitoring station and those measured outside the classroom was 0.82 (p < 0.001). Regarding ozone, its maximum outdoor concentration was 0.29 ppm and indoor concentrations were on average below 0.06 ppm (maximum = 0.17 ppm). The indoor/outdoor correlation coefficient was 0.72, and for every 1.7 ppm outside, there was 1.0 ppm inside (p < 0.05).
  
  
  CONCLUSIONS
  Since the highest outdoors O3 concentrations were observed between 11:00 and 14:00 hrs, it is recommendable to have recess before this time.
authors.affiliation: Centro de Investigación en Salud Poblacional (CISP), Instituto Nacional de Salud Pública (INSP), México.
authors.forename: M
authors.initials: M
authors.lastname: Cortez-Lugo
authors.forename: A
authors.initials: A
authors.lastname: Mercado-García
authors.forename: M
authors.initials: M
authors.lastname: Hernández-Avila
authors.forename: F
authors.initials: F
authors.lastname: Meneses-González
authors.forename: E
authors.initials: E
authors.lastname: Palazuelos-Rendón
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D016902:Air Pollution, Indoor / Q000032:analysis*; D008800:Mexico; D009569:Nitric Oxide / Q000032:analysis; D010126:Ozone / Q000032:analysis; D012578:Schools, Nursery / Q000592:standards*
chemical_list: D000393:Air Pollutants; D009569:Nitric Oxide; D010126:Ozone
vernacular_title: Evaluación de la calidad del aire interior y exterior en un jardín de niños de la Ciudad de México.