Assessment of Bioconcentration Factor of Chromium by Instrumental Neutron Activation Analysis in Argyrodiaptomus falcifer Daday, a Subtropical Freshwater Copepod

Abstract

The objectives of this study were to determine the capacity of the freshwater calanoid copepod Argyrodiaptomus falcifer (Daday, 1905) to accumulate Cr from water, to know the bioconcentration factors in order to evaluate its potential as a biomonitor, and to compare this with data previously obtained with Daphnia magna Straus under identical conditions. By static bioassays using triplicates and a control, a pool of A. falcifer was exposed to three concentrations of Cr (VI): 150 μg/L (T1), 280 μg/L (T2), and 350 μg/L (T3) for 48 h to later determine by Instrumental Neutron Activation Analysis the amount of Cr accumulated. A. falcifer accumulated Cr in all the three concentrations tested. The comparison of T1, T2, and T3 and the control showed significant differences (p<0.05) but not between the treatments (p>0.05). On the other hand, A. falcifer accumulated more Cr than D. magna, but these differences were not significant (p>0.05). Almost no information is available about metal toxicity in freshwater copepods so the reported results are of high importance in order to detect good biomonitors of freshwater Cr-polluted environments.