Breakdown of polycyclic aromatic hydrocarbons in different size fractions of marine sediments

Contamination of marine sediments is becoming increasingly important in defining environmental acceptability thresholds when planning remediation and restoration measures, as well as in assessing the quality of marine ecosystems and the contamination impact on their functionality. Bottom sediments naturally accumulate high concentrations of persistent organic pollutants that exceed the limits set by the Sediment Quality Guidelines (SQGs). This poses an ecotoxicological risk to marine organisms and, indirectly, to the human health. A comprehensive assessment of sediment quality is therefore important, especially when considering the spatial and vertical distribution of the most toxic contaminants in the different particle size fractions. Finer sediments are often considered important vectors of pollution due to their greater surface area and ability to absorb and retain pollutants. They are more prone than coarser grains to accumulate toxic substances and often become secondary pollution sources during resuspension phenomena, which can potentially harm organisms that come into contact with the contaminated sediments. This study aimed to determine the distribution of 17 polycyclic aromatic hydrocarbons (PAHs) in different particle size fractions of sediments sampled from a heavily contaminated area in the Gulf of Taranto, an area under high anthropic pressure. The data discussed in this paper are of great interest for predicting resuspension phenomena of contaminated sediments and for developing possible ex situ decontamination processes for dredged sediments.