ACCUMULATION OF CADMIUM, CHROMIUM, AND ZINC BY THE MOSS SPHAGNUM-PAPILLOSUM LINDLE

In a series of laboratory experiments employing radiotracer methodolog y, the uptake of Cd, Cr, and Zn by Sphagnum papillosum Lindle moss fro m solutions of deionized water and bog water was investigated. Bioaccu mulation of the metals was a passive process, since living and dead mo ss accumulated metal equally. No significant differences were found in metal uptake rates from single metal solutions and mixed metal soluti ons, suggesting insignificant competition between the metals occurred at the low concentration range used (10(-10) to 10(-7) M). Metal uptak e conformed with Freundlich adsorption isotherms. Concentration factor s of metals in Sphagnum papillosum in bog water (10(3) for Cd and Zn, 10(2) for Cr) were lower than in deionized water (10(4) for Cd and Zn, 10(3) for Cr), possibly due to metal complexation by dissolved organi c matter, competition by other major cations present in the bog water (Na+, K+, Mg2+, Ca2+) or complexation by chlorides in the bog water. W hile earlier studies have demonstrated the potential of using sphagnum mosses for monitoring environmental metal contamination, these experi ments are the first to assess metal uptake in moss using low, environm entally realistic metal concentrations. The results confirm that mosse s would be very effective bioindicators of environmental metal concent rations because the concentration of metal in the moss rapidly and dir ectly reflects the metal concentrations in the ambient water.