Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants with strong hydrophobicity that tend to accumulate in sediments, requiring long-term management in aquatic environments. This study investigated the distribution characteristics...
Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants with strong hydrophobicity that tend to accumulate in sediments, requiring long-term management in aquatic environments. This study investigated the distribution characteristics, source structure, and management oriented potential risk features of PAHs in surface sediments of Daecheong Lake by integrating long-term time-series data with sedimentary environmental characteristics. Surface sediment samples were collected from six sites in Daecheong Lake over a ten year period from 2015 to 2024.
The analysis of spatial and temporal distributions showed that total PAH concentrations exhibited site and year specific variations, with accumulation patterns differing according to sediment grain size composition and organic matter characteristics. Correlation analyses indicated that PAH distributions were not governed by a single sedimentary factor but rather reflected the combined influence of combustion derived inputs and sedimentary processes. Temporal variations also differed among sites and individual compounds. Source identification using molecular diagnostic ratios and multivariate statistical analyses revealed that combustion-related sources predominated across the study area, with high molecular weight PAHs exhibiting selective accumulation depending on sedimentary conditions.
To support management oriented prioritization, a screening framework based on predicted no effect concentration (PNEC) values was applied using a STE (Spatial, Temporal, and Extent factor) approach focused on identifying priority control substances. The STE evaluation integrated the spatial extent of occurrence, temporal persistence, and relative magnitude of concentration exceedance compared to reference levels to derive compound specific priority scores. As a result, Naphthalene was identified as the highest-priority control substance due to its persistent and repeated relative exceedance across all sites. Anthracene, Benzo[k]fluoranthene, and Benzo[a]pyrene were also identified as priority substances based on their long-term and spatially extensive exceedance characteristics, whereas other PAHs exhibited relatively limited exceedance patterns.
This study provides a comprehensive interpretation of PAH distribution and source characteristics in the sediments of Daecheong Lake using long-term monitoring data and proposes a management oriented framework for identifying priority control substances based on risk-related information. The STE approach applied in this study is not intended to perform a quantitative ecological risk assessment but rather serves as a decision-support tool for establishing management priorities based on relative exceedance characteristics. The proposed framework can be applied to sediment management strategies for other artificial and natural lakes in freshwater environments.