Occurrence, source and ecological risk assessment of polycyclic aromatic hydrocarbons in offshore sediment of Beibu Gulf

The concentrations of 16 PAHs in surface sediments of Beibu Gulf have been quantitatively analyzed. The potential sources of PAHs were explored, and the ecological risk level was investigated. Results showed that the total PAHs concentrations ranged from 14.30 ng·g−1 to 114.09 ng·g−1 (dry weight) and the 4-ring PAHs accounted for the largest proportion (30%—45%). The concentrations of 16 PAHs declined trend from the northeastern coast to the southwestern offshore zone with a decrease in the proportion of 4—6 rings PAHs decreased and an increase in the proportion of 2—3 rings PAHs. The PAHs pollution in surface sediments of Beibu Gulf was primarily from mix source, combustion source and petroleum source, with contribution rates of 38.2%, 36.5% and 25.3%, respectively. The ecological risk in the research sea area was relatively low. However, the presence of carcinogenic PAHs posed a certain degree of potential risk. This study addressed the shortcomings of existing research by proving a clearer understanding of the actual pollution status of the Beibu Gulf and offering comprehensive data support for PAHs pollution prevention and ecological environmental protection in the Beibu Gulf.