Determination of background geochemistry of an Amazon estuary: The Cuñaní Estuary - Amapá.

Abstract This study aims to determinate the background geochemistry values for 23 chemical elements on the Amapa coastline. To do so, 8 cores were sampled (≤70 cm) along the Cunani Estuary. The metal concentrations were measured by means of inductively coupled plasma mass spectrometry. In mg.kg-1, the background values for Ba, Sr, Y, Sc, V, Cr2O3, Co, Ni, Cu, Zn, Ga, As, Rb, Nb, Sn, Cs, Ta, W, Hg, Pb, Bi, Th, and U were, respectively, 392.41, 133.29, 29.22, 12.80, 109.13, 0.008, 13.82, 22.69, 19.73, 75.09, 19.50, 14.77, 94.81, 15.62, 3.38, 6.59, 1.05, 1.82, 0.04, 19.02, 0.27, 13.25, and 3.57. The background geochemistry values for the region are an important tool for monitoring the metal concentrations and serve as a baseline for comparison with possible incidents of contamination with these elements on the Amapa coast.