Heavy metals on tidal flats in the Yangtze Estuary, China

Five short cores were used to examine heavy metals on tidal flats in the Yangtze Estuary, China. Statistically insignificant trends in lead-210 and most metals with core depth are primarily due to high sedimentation rates. Metal contents are correlated with percent aluminum, which reflects the clay contents in the sediment, and they are also affected by proximity to sewage outlets and local industry. National standards for copper are exceeded in four cores, zinc in one core, and arsenic in all cores. Heavy metal contents are generally lower on the Yangtze tidal flats compared to most other estuaries because high sediment loads dilute metal inputs.