THE DIFFERENT IMPACTS OF HUMAN SOURCES ON THE SPATIAL DISTRIBUTION OF PAHs AND PCBs IN SURFACE SEDIMENTS IN THE NAKDONG RIVER ESTUARY, SOUTH KOREA

Abstract

The Nakdong River in South Korea is about 510 km long and is exposed to various potential sources of human pollution, such as urban dumping, industrial complexes, and input from many cities. The Noksan Dam, built in 1934, blocks the flow of the West Nakdong River, while the NRE Dam was completed in 1987 to regulate flow from the East Nakdong River. This study assessed the concentrations and trends of persistent contaminants in surface sediments, including 16 polycyclic aromatic hydrocarbons (PAHs) and 19 polychlorinated biphenyls (PCBs), and examined their origins. Eighteen surface sediment samples were collected on and around the barrier islands (Eulsukdo, Jinwoodo, and Sinjado) and near the Nakdonggang Estuary Bank from May 2015 to August 2016. The concentrations of PAHs (10.8&#8211 1,079.6 ng·g-1) and PCBs (197.0&#8211 1,131.0 pg·g-1) in the surface sediments revealed different spatial patterns for these compounds, suggesting that they partially originated from the use of commercial PCB products in adjacent industrial complexes. The analysis determined that PAHs originated from the combustion of fossil fuels and biomass, and the overall concentrations due to anthropogenic activity were related to the contributions of individual PAHs in most of the sediment samples. Compared to the sediment quality guidelines of the National Oceanic and Atmospheric Administration (NOAA) for PAHs and PCBs, they were less enriched the West Nakdong River, while the NRE Dam was completed in 1987 to regulate flow from the East Nakdong River. This study assessed the concentrations and trends of persistent contaminants in surface sediments, including 16 polycyclic aromatic hydrocarbons (PAHs) and 19 polychlorinated biphenyls (PCBs), and examined their origins. Eighteen surface sediment samples were collected on and around the barrier islands (Eulsukdo, Jinwoodo, and Sinjado) and near the Nakdonggang Estuary Bank from May 2015 to August 2016. The concentrations of PAHs (10.8&#8211 1,079.6 ng·g-1) and PCBs (197.0&#8211 1,131.0 pg·g-1) in the surface sediments revealed different spatial patterns for these compounds, suggesting that they partially originated from the use of commercial PCB products in adjacent industrial complexes. The analysis determined that PAHs originated from the combustion of fossil fuels and biomass, and the overall concentrations due to anthropogenic activity were related to the contributions of individual PAHs in most of the sediment samples. Compared to the sediment quality guidelines of the National Oceanic and Atmospheric Administration (NOAA) for PAHs and PCBs, they were less enriched