Control of the distribution of persistent organic pollutants in the Gulf of Biscay and Galicia: Polycyclic Aromatic Hydrocarbons (PAHs).

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are produced as a result of fires or combustion processes and are also natural components of coal and oil. Due to their persistence, potential to bioaccumulate and toxicity, the analysis of PAHs in sediment and shellfish is required for the MSFD and Regional Sea Conventions; including, at least, the determination of the concentrations of phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, chrysene, benzo[a]pyrene, benzo[g,h,i]perylene and indeno[123-c,d]pyrene.

In order to control the level of PAHs in the Iberian Northern platform, a sampling campaign (from the Portugal border to the border with France) was performed in which 69 marine surficial sediment samples were collected in 2016. Organic carbon and particle size analysis were performed to complete the sediments characterization and facilitate data interpretation. The PAH analysis included a first step of PLE Pressurized Liquid Extraction (PLE), followed by a cleaning up of the extract and the quantification of 35 parent and alkylated PAHs was performed by gas chromatography-mass spectrometry.

The obtained results revealed a higher presence of PAHs in the Eastern stations. In the absence of other sediment quality guidelines (SQG) polycyclic aromatic hydrocarbon concentrations in sediment were assessed against Effects Range-Low values, developed by the United States Environmental Protection Agency to assess the ecological significance of PAH concentrations in sediment. The determined concentrations indicated a presence of some stations with concentrations that exceeded the respective ERL indicating the possible biological toxicity of some sediments.