Spatial and seasonal variability of trace-element concentrations in sediments from the Santos-Cubatão estuarine system, São Paulo, Brazil

Quimica nova

Matos, Rosa Helena Ribeiro¹  Kristosch, Giane Chaves¹  Luiz-Silva, Wanilson²  Machado, Wilson³ 

[1] Universidade Estadual Paulista, Rio Claro;Universidade Estadual de Campinas, Campinas;Universidade Federal Fluminense, Niterói

关键词: heavy metals;    sediment geochemistry;    contamination.;   

DOI  :  10.1590/S0100-40422006000200016

学科分类：化学（综合）

来源: Sociedade Brasileira de Quimica

【 摘 要 】

Multi-elementanalyses of sediment samples from the Santos-Cubatão Estuarine Systemwere carried out to investigate the spatial and seasonal variability of trace-elementconcentrations. The study area contains a rich mangrove ecosystem that is ahabitat for tens of thousands of resident and migratory birds, some of themendangered globally. Enrichments of metals in fine-grained surface sedimentsare, in decreasing order, Hg, Mn, La, Ca, Sr, Cd, Zn, Pb, Ba, Cu, Cr, Fe, Nb,Y, Ni and Ga, relative to pre-industrial background levels. The maximum enrichmentranged from 49 (Hg) to 3.1 (Ga). Mercury concentrations were greater in theCubatão river than in other sites, while the other elements showed greaterconcentrations in the Morrão river. Concentrations of Mn were significantlygreater in winter and autumn than in summer and spring. However, other elements(e.g. Cd and Pb) showed the opposite, with greater concentrations in summerand spring. This study suggests that seasonal changes in physical and chemicalconditions may affect the degree of sediment enrichment and therefore make theassessment of contamination difficult. Consequently, these processes need tobe considered when assessing water quality and the potential contamination ofbiota.

【 授权许可】

CC BY