title: Determination of carbonyls and their sources in three sites of the metropolitan area of Costa Rica, Central America.
abstract: Ambient levels of carbonyl compounds and their possible sources were studied at three places in the metropolitan area of Costa Rica, including a residential, an industrial, and a commercial downtown area with high vehicular flow, during the periods of April-May and September-December 2009. Fifteen carbonyl compounds were identified in the ambient air, of which acetone was the most abundant carbonyl, followed by formaldehyde and acetaldehyde. Concentrations were highest in rainy season at all sites and lower in dry season. These decreases in concentration are explained by the influences of both photochemical reactions and local meteorological conditions. The strong correlation between C1-C2 and C3 indicated a common origin for these carbonyls. The C1/C2 ratios varied between 0.49 to 1.05, values which can be considered typical of an urban area.
authors.affiliation: Laboratorio de Análisis Ambiental, Escuela de Ciencias Ambientales, Universidad Nacional, Campus Omar Dengo, Heredia, Costa Rica. jherrer@una.ac.cr
authors.forename: Jorge Herrera
authors.initials: JH
authors.lastname: Murillo
authors.forename: José Félix Rojas
authors.initials: JF
authors.lastname: Marín
authors.forename: Susana Rodríguez
authors.initials: SR
authors.lastname: Román
mesh_terms: D002947:Cities; D003364:Costa Rica; D004784:Environmental Monitoring / Q000379:methods*; D004785:Environmental Pollutants / Q000737:chemistry*; D009930:Organic Chemicals / Q000737:chemistry*; D012621:Seasons
chemical_list: D004785:Environmental Pollutants; D009930:Organic Chemicals