HR: 0800h
AN: A11A-0860    [Abstracts]
TI: Deposition of Carbonaceous Particles on the Historical Building "Ruinas de Caparra" in Puerto Rico
AU: * Caro-Gautier, H A
EM: hcaro@adam.uprr.pr
AF: Institute for Tropical Ecosystem Studies and Department of Chemistry, University of Puerto Rico, San Juan, Puerto Rico, University of Puerto Rico PO Box 21910, San Juan, PR 00931-1910 Puerto Rico
AU: Lugo-Vega, J
EM: johnny.lugo@gmail.com
AF: Institute for Tropical Ecosystem Studies and Department of Chemistry, University of Puerto Rico, San Juan, Puerto Rico, University of Puerto Rico PO Box 21910, San Juan, PR 00931-1910 Puerto Rico
AU: Lugo-Vega, J
EM: johnny.lugo@gmail.com
AF: Graduate School of Public Health, Department of Environmental Health, Medical Sciences Campus, University of Puerto Rico, San Juan, Puerto Rico, San Juan, PR 00918 Puerto Rico
AU: Mayol-Bracero, O L
EM: omayol@adam.uprr.pr
AF: Institute for Tropical Ecosystem Studies and Department of Chemistry, University of Puerto Rico, San Juan, Puerto Rico, University of Puerto Rico PO Box 21910, San Juan, PR 00931-1910 Puerto Rico
AU: Rios-Davila, R
A11A-0860 AF: Graduate School of Public Health, Department of Environmental Health, Medical Sciences Campus, University of Puerto Rico, San Juan, Puerto Rico, San Juan, PR 00918 Puerto Rico
AB: The deposition of atmospheric pollutants on historic buildings can damage the outer layers of the substrate. One of the main components of these layers, particularly, in areas exposed to combustion-derived air pollution, is carbonaceous particles embedded in gypsum. Our study was conducted at "Ruinas de Caparra", the remaining foundations of the first Spanish settlement in Puerto Rico (1508-1511). Two types of samples were collected: direct samples from the substrate surface layers and aerosol samples from the air to which the ruins are exposed. The direct samples were taken from both damaged (black) and undamaged (white) layers of the stone surfaces and the elemental and mineralogical properties were determined. Scanning electron microscopy/energy dispersive spectrometry analyses of the black layers showed the presence of carbonaceous particles and gypsum crystals typical from fossil fuel combustion. X-ray diffraction analyses also confirmed the presence of gypsum in the black layers; this was not observed in the white layers. Thermogravimetric analysis results for a black sample show a possible weight loss of organic compounds at 317°C and inorganic compounds at 687°C. On the other hand, the white sample only showed a weight loss due to inorganics compounds at 710°C. Results from aerosol sampling showed that the mean concentrations of both particle number and black carbon were typical of urban polluted areas (10000 to 20000 particles cm^-3 and 800 to 1500 ng m^-3, respectively), with maximum concentrations of 59000 particles cm^-3 and 3380 ng m^-3 , respectively. These maxima values corresponded to the early traffic hours between 6am and 10am, local time. Additional results, including the concentrations of elemental carbon and organic carbon to which the ruins are exposed on a daily basis, will be presented.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 4801 Aerosols (0305, 4906)
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005