Heavy metals in the bottom sediments of the Furo of Laura estuary, Eastern Amazon, Brazil

Universidade Federal Rural da Amaz?nia. Programa de P?s-Gradua??o em Aquicultura e Recursos Aqu?ticos Tropicais. Bel?m, PA, Brazil. Universidade Federal Rural da Amaz?nia. Instituto S?cio Ambiental e dos Recursos H?dricos. Bel?m, PA, Brazil. Minist?rio da Sa?de. Secretaria de Vigil?ncia em Sa?de. Instituto Evandro Chagas. Ananindeua, PA, Brasil. Minist?rio da Sa?de. Secretaria de Vigil?ncia em Sa?de. Instituto Evandro Chagas. Ananindeua, PA, Brasil. Minist?rio da Sa?de. Secretaria de Vigil?ncia em Sa?de. Instituto Evandro Chagas. Ananindeua, PA, Brasil. Universidade Federal do Par?. Faculdade de Engenharia Sanit?ria e Ambiental. Bel?m, PA, Brazil. Universidade Federal Rural da Amaz?nia. Programa de P?s-Gradua??o em Aquicultura e Recursos Aqu?ticos Tropicais. Bel?m, PA, Brazil. The Furo of Laura is an economically important river in the Amazon estuary. Thus, in the present study, we evaluated the metal distribution (Al, Cd, Co, Cu, Cr, Fe, Ni, and Mg) in the bottom sediments of this river. The sediments were sampled at four points every 2 months for a year with an Ekman-Birge sampler. After microwave acid digestion, the metal levels were determined by optical emission spectrometry with inductively coupled plasma. The particle size and organic matter content influenced the concentration of the metals. The sediments were not enriched by the analyzed metals; the estuary therefore retained the characteristics of an uncontaminated environment, thus serving as a reference environment for comparison.