Baseline Study of Trace Element Concentrations in Sediments of the Intertidal Zone of Amazonian Oceanic Beaches

Analyzing the presence and quantifying trace elements is of paramount importance to understand natural environmental processes monitor degree anthropogenic disturbance mitigate impacts already caused. Here, we aimed establish a baseline profile concentrations in sandy sediments intertidal areas three Amazonian beaches (Brazil). For each beach, were collected from different sectors (south, center, north) five shoreline distance levels (from high- low-water mark), totalizing 15 samples per beach. The concentration (Mg, Al, P, S, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Br, Rb, Sr, Y, Zr, Cd, Sn, I, Hg, Pb) was determined by Total reflection X-ray Fluorescence spectrometry. Sediment also characterized for its grain size, organic matter, pH. To assess possible enrichment due activities compared element with values Earth’s crust calculated pollution indexes: geoaccumulation index (Igeo), ecological risk (RI), contamination factor (CF), load (PLI), sediment quality guideline (SQG), threshold effects level (TEL) probable (PEL). Individual metal did not vary significantly between beaches, sectors, or sample levels, evidencing homogeneity composition across this environment. Igeo indicated 62.2% sampling stations uncontaminated, 20.0% uncontaminated moderately contaminated, 4.44% (two stations) strongly same two classified as high RI. Most points presented low CF. Cadmium Hg only that showed moderate very According SQGs, 77.7 8.8% above effect (SQG-TEL) (SQG-PEL), respectively. All non-polluted according PLI. Our results show present safe almost demonstrating good state preservation. indexes non-polluted, except Cd few specific points.