Levels of trace metals and effect of body size on metal content of the landsnail Levantina hierosylima from the West Bank-Palestine

Abstract

Levels of four trace metals (Cu, Zn, Cd and Pb) were determined in the landsnail Levantina hierosylima from four locations in the West Bank. Average concentration of the metals was 126.9, 42, 20.2 and 19.4 ppm for Cu, Zn, Pb and Cd, respectively. Significant differences in metal concentrations were observed between snails from the four sampling sites (Jerusalem, Abu-Dies, Qarawa, and Taibeh). Differences are most probably due to atmospheric fallout of metals from traffic roads and industrial facilities. Effect of snail size (weight and shell width) on metal content was investigated for the four metals. Plotting metal content against soft tissue weight resulted in significant relationships. Small snails were found to be richer in Zn, Cd and Pb than larger ones. Regression coefficients for the relationships were 0.75, 0.76 and 0.81 for Pb, Cd and Zn, respectively. Copper content was directly related to body weight (regression coefficient = 0.96) indicating that Cu concentration is independent of body weight. Plotting metal content against shell width indicated similar results but with less strong correlation coefficients. L. hierosylima is a promising bioindicator for metal pollution and further laboratory investigations are needed in order to know more about the uptake and release of metals by this organism.