Metals and metalloids in a first order stream of the Atlantic rainforest: abiotic matrices, bioaccumulation in fishes and human health risk assessment

Abstract

Background and aim: Metals and metalloids have been found in several streams and rivers from the Atlantic Rainforest (ARF), one of the world´s leading biodiversity hotspot, which may represent a risk for environmental and human health. The aims of this study were: 1) to evaluate the accumulation and distribution of 24 trace elements in water, sediments and fish tissues (muscle and gills) of sixteen species from the Atlantic Rainforest, 2) to explore bioaccumulation patterns in fish tissues and abiotic matrices, and 3) to assess the impact of metal and metalloids on the human health from water and fish consumption. Methods: Water, sediments and fish samples were collected from Ramos Stream (Misiones Province, Argentina). The concentrations of Ag, Al, As, Ba, Be, Cd, Co, Cr, Cs, Cu, Fe, Ga, Hg, Li, Mg, Mn, Ni, Pb, Se, Sr, Ti, U, V and Zn were determined by Quadrupole Inductively Coupled Plasma Mass Spectrometry. Bioaccumulation factors (BAFs) were used to evaluate bioaccumulation of metals and metalloids in relation to water and sediment. The Hazard Quotient (HQ), Hazard Index (HI) and Target Hazard Quotient (THQ, general and fisherman populations) were calculated to assess the non-carcinogenic human health risk from water and fish consumption. Results: The concentrations of several elements in water and sediment were higher than the international guidelines for aquatic biota protection. Levels of As, Pb and Zn in muscle and gills were above national and international guidelines for human consumption. The bioaccumulation factors ranged from 749 to 13,029 being higher in gills than in muscle. The HQ and HI ranged from 0.001 to 0.015. The THQ for each element and total THQ values were lower than 0.1. Conclusion: Bioaccumulation factor suggests that several species have a moderate capacity to incorporate some metals and metalloids from the abiotic matrices. According to the HI and THQ values found, there is no risk to human health from consumption of water and fish.