Assessment of Heavy Metal Distributions in Sand Beaches in the Maltese Islands

Abstract

This study focuses on the quantification of heavy metals present in 18 sand beaches on the islands of Malta and Gozo. A total of 134 samples were collected, digested using Aqua Regia, and analysed using flame AAS to find the concentration of six heavy metals. Concentrations obtained in descending order are: Sr > Fe > Mn > Pb > Zn > Cu. Using PCA, Fe and Mn resulted as homogenous distributions with a probable prevalent lithogenic origin. Pb is possibly dominantly anthropogenic, while Cu and Zn are of a mixed nature. Cluster analysis was used to prove the interaction between concentrations and different bays from where the samples were gathered. This showed that Ballut Reserve Bay and Rinella Bay in Malta and Marsalforn Bay in Gozo are amongst the bays most affected by heavy metal content. It has been observed that bays with higher heavy metal content lie in the same zones with the highest geological wear rate induced by sea waves. Health risk assessment undertaken for adults and children shows negligible effects of non-carcinogenic risk and cancer risk indices. Potential ecological risk computed for the concentrations obtained showed considerable Cu risk and a moderate Pb risk at the bays analysed, none of which are contaminated with these elements.