Lead concentration in different trophic levels: experimental analysis

Abstract

This study aimed to experimentally evaluate the capacity of lead (Pb) accumulation and passage at different trophic levels. To do so, the aquatic macrophyte M. linifera, grasshoppers of the T. surinama species, and Theraphosa sp. spiders were collected and subjected to experiments 1, 2, and 3 with 1 g.L-1, 0.1 g.L-1 of Pb, and without lead, respectively. After analyzing the results using a flame atomic absorption spectrometer, the presence of Pb was detected in the analyzed trophic levels. The highest concentration of Pb was found in the aninga root in experiment 2 (219,705.6 mg.Kg-1), and the lowest concentration was found in the leaf of experiment 1 (79.4 mg.Kg-1). The grasshoppers in experiment 1 and 2 did not show traces of Pb, only in their feces, the highest being 201.98 mg.Kg-1 and the lowest being 8.74 mg.Kg-1.Traces of Pb were also found in the spiders, with the highest concentration detected in experiment 1 (7.42 mg.Kg-1). The study revealed an increase in Pb concentration in the experimental food chain across the three trophic levels. T. surinama acted as a lead desconcentrator in the food chain, returning the ingested lead to the environment, creating a cycle in the aquatic environment where lead can be reabsorbed by the plant.