A Chemo-Metric Approach to Assess Heavy Metal Pollution Status in a Human Impacted Coastal System

TRUCHET, DANIELA M.; NEGRO, CARLOS LEANDRO; BUZZI, NATALIA S.; MORA, M. CELESTE; MARCOVECCHIO, JORGE E.

Congreso; SETAC Latin American 14th Biennial Meeting; 2021

Sociedad de Toxicología y Química Ambiental Argentina

Estuaries are among the most threatened coastal environments sincethey receive several pollutants from riverine discharges, large urbansettlements, industries and ports. Human pressures are enhanced indeveloping countries of South America, such as Argentina, where thebiota is at risk due to several pollutants (metals, POPs andmicroplastics), and therefore, biomonitoring of these areas is highlyrecommended. However, few studies have achieved this concern and thescientific tools displayed in an integrative way where abiotic and bioticmatrices are combined using multiple indices were even less studied.The current study compared metal concentrations (Cd, Cu, Pb, Zn, Mn,Ni, Cr, Fe) in sediments and a resident benthic crab species, Neohelicegranulata and the biochemical biomarkers (CAT, GST, H2O2, MT) inthis organisms in a salt marsh (SM) and a mudflat (M) in different stations (autumn and spring) of a SW Atlantic estuary (Bahía Blancaestuary, BBE) in Argentina. This area is currently influenced by severalindustrial and domestic discharges, ports and large scale fisheries.Metals in sediments did not exhibit significant differences between sitesand seasons, except for Mn that was higher in SM during spring. Crabsbioaccumulated more Cu from sediments during autumn than spring forboth sites. Except for Cd in M, Mn, Ni and Fe in SM, metals did notexhibit significant differences between sites, but tended to increase inautumn at both sites. Through geochemical indices, it was observed thatsediments were low to medium polluted with probable adversebiological effects to the biota. Some of the biochemical analyses applied(i.e., IBR) demonstrated high values in the SM during spring with agreat contribution of H2O2 and GST. By multivariate analyses (Pearsoncorrelations and PCA), it was possible to observe that the biomarkersinduction might be due to natural intrinsic factors such as energetic costsfor reproduction and not strictly metallic pollution. But also, it should beconsidered that during spring, the available organic matter in the estuaryis higher and specifically in the SM that also uptakes metals comingfrom plants. These metals are ultimately incorporated into the bodyburden of organisms and some correlated metals like Zn, Cu, Mn andCd can cause biomarkers induction