Evaluation of metal exposure through the composition of essential and toxic micro-minerals in freshwater turtles (Phrynops geoffroanus) from a Brazilian river

Abstract

This study aimed to evaluate the metal exposure through the concentration of essential and toxic micro-minerals in biological samples of Phrynops geoffroanus from an anthropized river. The work was carried out in four areas with different flow characteristics and uses of the river, where individuals of both sexes were captured during the dry and rainy seasons. The elements Al, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, and Zn, were quantified in samples of serum (168), muscle (62), liver (61), and kidney (61) by Inductively Coupled Plasma Optical Emission Spectrometry. The concentration of the elements varied according to the sample type, being higher in the liver and the kidney. In the serum, many elements were below the limit of quantification, but it was possible to determine Al, Cu, Fe, Mn, Pb, and Zn. The liver showed high levels of Cu, Fe, and Pb, and muscle for Ni, Pb, and Zn, with most of the elements accumulated in the kidney tissue (Al, Cd, Co, Cr, Mn, Mo, and Ni). There was no significant difference between sex in the accumulation of elements. Between seasons, Cu was higher in serum and Mn in muscle and liver in the dry period, while in the kidney, almost all the elements were higher in the rainy period. The concentrations of the elements in the samples indicated a high degree of environmental contamination, representing risk in the use of the river and consumption of food from local fisheries.