Spatial Distribution and Contamination Assessment of Heavy Metals in Coastal Wetland Sediments

This study assessed heavy metal distribution and ecological risks across 28 surface sediment sites (0–20 cm) in the Tianjin Binhai New Area. Average concentrations met Class I marine standards. Independent t-tests showed no significant differences (p > 0.05) between riverine and coastal wetlands . However, Cd, Hg, and Pb exhibited high variability, linked to intensive shipping and industrial runoff from the Port of Tianjin, Lingang, and Dagang zones . While integrated risk was low, Hg posed localized moderate risk. Seasonal discharge and redox variations may further influence metal dynamics . These findings provide a refined baseline for port-industrial bays.