Arsenic, antimony, gold, and mercury levels in the soft tissues of intertidal and terrestrial molluscs and trace element composition of their shells.

The concentration levels of As, Au, Hg, and Sb in the fleshy tissues of the giant African land snails (Archachatina Marginata) and periwinkles (Littorina littorea) have been measured by neutron activation analysis (NAA). Post-irradiation separation of 76As, 198Au, 197Hg, and 122Sb as bromides after wet-ashing the samples in a concentrated H2SO4-HBr medium was employed. The concentration ranges of 0.015 approximately 2.48, 0.037 approximately 0.091, 0.018 approximately 0.072, and less than 0.01 approximately 0.25 microgram/g wet weight were determined for As, Au, Hg, and Sb, respectively. The periwinkles showed higher concentrations of As, Au, and Hg than the snails. The concentrations of 16 elements, Al, Br, Ca, Cl, Co, Eu, Fe, K, La, Mn, S, Sc, Si, Sm, Sr, and Zn also have been determined in the calcareous shells of these molluscs.