Polybrominated diphenyl ethers in Mendoza river basin and El Carrizal reservoir: levels, distribution and correlation with physico-chemical variables

ALTAMIRANO, J C; LANA, N B; D`ANGELO, JOSÉ A; CIOCCO, N

Kyoto, Japón

Simposio; 5th International Symposium on Brominated Flame Retardants, BFR 2010; 2010

Little information is found in the open literature on polybrominated diphenyl ethers (PBDEs) in abiotic systems of South America, especially in Argentina. In this work, four PBDE congeners were determined in sediment samples of Mendoza River basin and El Carrizal reservoir from Mendoza province, Argentina.  Additional physicochemical analysis of the sediment samples, including sample pH, electrical conductivity (EC), and total organic carbon (TOC) were carried out. Semi-quantitative determinations of functional groups of the organic matter (OM) were conducted by Fourier transform infrared (FT-IR) spectrometry. The results were analyzed using principal component analysis (PCA) in order to identify potential correlation between these variables and PBDEs concentration.The most abundant PBDEs congeners found in sediment samples of Mendoza River basin were BDE-100, BDE-47 and BDE-99, which were within a concentration range of 47.1-1338.1, 12.3-1122.9, 39.8-1112.2 pg g-1, respectively. The geographical sites where PBDEs have been found were associated with urban and industrialized area. The most abundant PBDEs congeners found in sediment samples of El Carrizal reservoir were within a concentration range of 16.1-163 pg g-1  for BDE-47, not detected (n.d.) - 15.3 pg g-1  for BDE-99 and n.d.-9.8 pg g-1 for BDE-153.PCA results lead to data groupings suggesting a relationship between presence of PBDEs and content of oxidized organic matter (lower Al/Ox ratio). More importantly, the results indicate that the presence of hydrophobic organic contaminants, such us PBDEs congeners, is related to organic matter characterized by lower values of CH2/CH3 ratios. The latter suggests enhanced carbon-carbon bond breaking of the organic material during oxidation, resulting in comparatively more branched or shorter hydrocarbon side chains linked to the macromolecular structure.The results of this study suggest that transport and accumulation of PBDEs in sediment samples is correlated with degradation level of the organic matter present in it.