Geochemical Characteristics of Surface Sediments in the Intertidal of Hallyeohaesang National Park, South Korea

To evaluate the characteristics of sediments and the degree of heavy metal pollution in Hallyeohaesang National Park, sediment samples were analyzed for grain size, total organic carbon (TOC), and heavy metals (Fe, Li, Mn, Cr, Ni, Pb, Cu, Zn, As, Cd, Hg). The sediments were primarily composed of gravel and sand, but certain areas exhibited a high proportion of silt and clay. The TOC content was relatively higher in areas with finer sediment fractions, indicating a strong relationship between grain size and or- ganic matter. The distribution of heavy metals was influenced by environmental factors such as grain size, organic matter, and redox conditions. Cr and Ni were primarily associated with natural origins, while Hg, Cd, and Cu were significantly affected by localized pol- lution sources. The pollution assessment revealed the presence of both polluted and unpolluted conditions within the study area. In specific areas, a high risk level for benthic organisms was identified, indicating severe ecological implications.