Spatial Distribution and Potential Toxicity of PAHs in Contaminated Sediments in Korea Using a Passive Sampler-Based Approach

Due to the bioaccumulation and adverse health effects of polycyclic aromatic hydrocarbons (PAHs) on aquatic organisms, evaluating their potential toxicity in sediments is essential. Particularly, as industrial activities and urbanization expand, PAHs are increasingly being introduced into marine ecosystems. Passive samplers (PS) have been widely used to measure the concentration of freely dissolved (C_free) PAHs and assess their potential toxicity in sediment porewater. In this study, C_free was measured using passive samplers to assess the potential toxicity of contaminated sediments near industrial facilities in Korea. The maximum C_free levels in OS, JS, and OP were 201 ng/L, 70 ng/L, and 77 ng/L, respectively, indicating relatively high levels compared to other areas in Korea. Additionally, the spatial distribution of C_free was influenced by regional characteristics and sediment properties. The potential toxicity was evaluated using four key factors: C_free, biota-sediment accumulation factor (BSAF), interstitial water toxicity units (IWTUs), and chemical activity (a). Although the sedimentary PAH levels in these three harbors may not currently exhibit adverse effects on organisms based on these factors, inner sites could pose potential toxicity risks in the future. The findings of this study suggest the necessity for further research using PS techniques at potentially contaminated sites to enhance understanding of ongoing contamination, ecological risks, and strategies for improving sediment management.