Use of the light absorption coefficient to monitor elemental carbon and PM2.5 - Example of Santiago de Chile

Gramsch, E; Ormeno, I; Palma, G; Cereceda-Balic, F; Oyola, P

Abstract

The optical absorption coefficient, particulate matter with an aerodynamic diameter 2.5 mum, and elemental carbon (EC) have been measured simultaneously during winter and spring of 2000 in the western part of Santiago, Chile (Pudahuel district). The optical measurements were carried out with a low-cost instrument recently developed at the University of Santiago. From the data, a site-specific mass absorption coefficient of 4.45 +/- 0.01 m(2)/g has been found for EC. In addition, a mass absorption coefficient of 1.02 +/- 0.03 m(2)/g has been obtained for PM2.5. These coefficients can be used during the colder months (May-August) to obtain EC concentration or PM2.5 from a measurement of the light absorption coefficient (sigma(a)). The high correlation that has been found between these variables indicates that a. is a good indicator of the degree of contamination of urbanized areas. The data also show an increase in PM2.5 and EC concentration during winter and an increase in the ratio of EC to PM2.5. When the EC/PM2.5 ratio is calculated during rush hour (7:00 a.m.-11:00 a.m.) and during part of the night (9:00 p.m.-2:00 a.m.), it is found that the increase is caused by higher concentration levels of EC at night. These results suggest that the rise in the EC concentration is caused by emissions from heating and air mass transport of pollution from other parts of the city, while traffic contribution remains approximately constant.

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Título según WOS: Use of the light absorption coefficient to monitor elemental carbon and PM2.5 - Example of Santiago de Chile
Título de la Revista: JOURNAL OF THE AIR WASTE MANAGEMENT ASSOCIATION
Volumen: 54
Número: 7
Editorial: AIR & WASTE MANAGEMENT ASSOC
Fecha de publicación: 2004
Página de inicio: 799
Página final: 808
DOI:

10.1080/10473289.2004.10470956

Notas: ISI