Arsenic accumulation in intertidal macroalgae exposed to sewage discharges

Arsenic is a widely distributed element in marine ecosystems. The main anthropogenic sources of this contaminant are domestic and industrial wastewaters, and since it can be harmful to humans even at low concentrations, it has been ranked as one of the top hazardous substances. Therefore, the analysis of arsenic is an essential task to assess the potential environmental and human health risk associated with sewage discharges. The accumulation of total arsenic on intertidal rocky shore macroalgae exposed to contaminated sewage discharges was measured in five macroalgae species (Asparagopsis armata, Codium sp., Plocamium cartilagineum, Saccorhiza polyschides and Ulva sp.). Differences in the concentrations of arsenic were examined in the seawater and in the macroalgae species. The results showed significantly higher concentrations of arsenic near the sewage discharges in all the species except S. polyschides. Although the information obtained from total arsenic determination is not enough to assess the toxicological risk in the environment, this paper gives an important contribution on contamination risks and helps in choosing potential good biomonitors.