Influence of anthropogenic activities on trace metal accumulation in Brazilian mangrove sediments

Autores

  • Christian J. Sanders Universidade Federal Fluminense

Palavras-chave:

Enrichment factors, heavy metal, metal flux, urban development, mining activity, Hg, Zn, Pb, Ni, Co, Mn, Cu

Resumo

Two sediment cores were collected at the margins of well-developed mangrove forests to study the effects of anthropogenic activities in the Paranagua region of Brazil. Calculations of sediment trace metal content, flux, and enrichment factors (EF) were performed. Trace metal (Hg, Zn, Pb, Ni, Co, Mn and Cu) contents showed differing values down core and amongst sites, which were not indicative of metal accumulation rates or EF. Slight enrichments of these metals were observed congruent with mining activities in the area occurring prior to 1900. Multiple rapid increases of flux rates were observed, one congruent with pre-industrial mining activity which was observed in both sediment cores. The other flux spike was only detected in one sediment core, occurring post 1990, and was not accompanied by any enrichment. This increase in flux is believed to be due to upstream urban development causing increased fine grain particle deposition in the mangroves of Laranjeiras Bay. Beyond assessing impacts of anthropogenic activities on mangroves of this area, an additional focal point of this work is to show the significance of content flux and EF in studies concerning coastal sediment pollution research. The validity of using flux and EF data, in addition to metals contents, to discern contamination trends in mangrove sediments is discussed.

Downloads

Publicado

08-11-2017