Cellular compartmentalization and heavy metal load in the moss <i>barbula lambarenensis</i> around a mega cement factory in southwest Nigeria

Abstract

Natural populations of ectohydric moss Barbula lambarenensis growing in a cement polluted environment  were collected and subjected to Sequential Elution Technique using 0.2M EDTA as the extracting agent, in order to quantify the Pb, Cu, Cr, Cd and Zn contents of the extracellular, intracellular and particulate fractions. The selected heavy metal concentrations in the B. lambarenensis extracts were read using Atomic Absorption Spectrophotometry (Buck Scientific 210 VGP). The data obtained were subjected to one-way  Analysis of Variance and Duncan Multiple Range Test to separate means that were statistically the same. Results showed that Pb, Cu and Zn had higher concentrations in the intracellular compartment while Cr and Cd were found to be more concentrated in the extracellular compartment of B. lambarenensis. In term of their solubility across the cell membrane, Cu (41%), Cr (43%) and Cd (43%) were more soluble; hence high bioavailability and toxicity potential to the moss. Solubility of Pb (49%) and Zn (54%) were relatively low compared to Cu, Cr  and Cd and these results into low toxicity to B. lambarenensis. It was concluded that moss can be effectively used  as biomonitors/bioindicator of environmental pollution due to dust particles from cement factories.

Keywords: Bioconcentration, Toxicity, Bioavailability, Biomonitor, transmembrane, Solubility