Oven-dried mosses as tools of trace element detection in polluted waters: a preliminary study under laboratory conditions

The concentration of 11 trace elements, plus Ca, Mg, Na and K was measured in moss bags of living and dead (oven-dried at 105°C) Platyhypnidium riparioides after a 1-week exposure to tap water, and to 0.21, 1.0, 2.5 and 4.0 μM solutions under laboratory conditions, with the aim of (1) observing the accumulation curves and (2) performing a statistical comparison in element concentrations. Uptake occurred both in living and in dead mosses following similar patterns in the two materials: a linear uptake was observed for Cd and Ni, a saturation curve for As, Cu, Hg and Pb, an unclear trend for Al and Mn and a trend leading to a maximum for Cr and Fe. An evident efflux of K indicated alterations in cell membrane permeability in living mosses and cellular damage in dead mosses. Living mosses accumulated higher concentrations of Cr (+4/+49%) and Mn (+124/+216%), while dead mosses accumulated higher concentrations of Cd (+13/+50%), Cu (+26/+51%), Ni (+22/+139%) and Zn (+22/+63%). Dead mosses maintained a considerable uptake efficiency for several trace elements, and sometimes even increased it as compared with living mosses, thus proving to be suitable for standard kits.