Metals in a Marine Sediment Core from Near Ma Wan, Hong Kong

Abstract

The profiles of eight major and trace metals in a 5 m sediment core, from Ma Wan, Hong Kong, exhibit an irregular decrease down to 1.2 m, followed by more horizontal profiles. On normalization of the concentrations with respect to iron, to correct particle-size changes, the profiles are flatter over the initial 1.5 m depth. The profile for Cu shows thesharpest initial decline with depth, down to0.10–0.15 m, due to pollution from waste effluentsfrom West Kowloon since the 1950's. The extractionefficiency of dilute HCl varies considerably for themetals in the core. Correlations are presented whichinvolve the extraction efficiencies, or extracted ionconcentrations, but an underlying reason for thestatistical significance of these correlations is theparticle-size dependence of metal concentrations alongthe core depth.