Polycyclic aromatic hydrocarbons (PAHs) in marine sediments of the Hellenic coastal zone, eastern Mediterranean: levels, sources and toxicological significance

Abstract

Purpose Polycyclic aromatic hydrocarbons (PAHs) are widespread in sediments, particularly near areas of intense human activities. Due to their mutagenic and carcinogenic behaviour, PAHs are classified as priority contaminants to be monitored in environmental quality control schemes. The purpose of this study was to determine the levels of PAHs in major coastal areas of Greece that receive various pressures, investigate their sources and evaluate their potential toxicity by comparison against effects-based Sediment Quality Guidelines (SQG). Materials and methods Forty-one sediment samples were collected from four areas of the Hellenic coastline. PAH concentrations were determined by GC-MS, after Soxhlet extraction and fractionation by silica column chromatography. Source apportionment was conducted by isomeric ratio diagnostic criteria. The mean quotient Effects RangeMedian (m-ERM) was used to evaluate the potential of adverse effects posed to benthic organisms. Results and discussion The levels of PAHs were found to vary widely from 100 to more than 26,000 ng g −1 . The highest levels were found in the close vicinity of an alumina production plant in the Gulf of Corinth. High levels of PAHs were also found at a few sites in each of the areas studied, close to a nickel production plant (North Evoikos Gulf), at the rainwater and wastewater outfalls of the great urban areas of Athens and Thessaloniki and at the industrialized area of Elefsis Bay (Saronikos Gulf). At the most contaminated sites PAH had a pyrolytic origin. Comparison of PAH levels to the SQG indicated that less than 15% of the sites studied have an intermediate probability (24-49%) of being toxic. Conclusions In general, discrete point sources were identified as the major contributors of PAH contamination in the Hellenic coastal zone. Therefore, source control measures should be considered for protecting, or restoring, sediment quality, particularly in areas that support a diversity of anthropogenic activities (e.g. fishing, tourism, industry).

Modelling dolphin distribution within an Important Marine Mammal Area in Greece to support spatial management planning

“…Colossal volumes of hazardous industrial waste have been disposed off into the Gulf for over half a century (Bearzi et al, ; Issaris et al, ). Although the disposal of red mud at sea stopped in 2011 (Issaris et al, ; http://www.alhellas.com), contamination through the food web may expose dolphins to the immunotoxic and other detrimental effects of persistent environmental pollutants (Botsou & Hatzianestis, ; Desforges et al, ; Jepson et al, ; Malea, Haritonidis, & Kevrekidis, ; Tsangaris et al, ). Preferred dolphin habitat overlaps with areas of red mud disposal and dolphins show no avoidance of red mud areas (Bearzi et al, ), as further documented in this study.…”

Occurrence, sources and transport pathways of natural and anthropogenic hydrocarbons in deep-sea sediments of the eastern Mediterranean Sea

“…Aliphatic hydrocarbons and PAHs have been investigated over the last decades in surficial sediments of the EMS, primarily in coastal or shallow basin sites in the Aegean Sea, southern Italy, the coast of Egypt and the Adriatic Sea (Aboul-Kassim and Simoneit, 1995;Alebic-Juretic, 2011;Botsou and Hatzianestis, 2012;Cardellicchio et al, 2007;Gogou et al, 2000;Gonul and Kucuksezgin, 2012;Guzzella and De Paolis, 1994;Marcomini et al, 1986;Nemr et al, 2007;Sklivagou et al, 2008;Yilmaz et al, 1998). However, there is an important lack of data regarding their occurrence in deep basins, which might represent a long-term sink for hydrocarbons.…”

Total thiol redox status as a potent biomarker of PAH-mediated effects on mussels

“…Although Botsou and Hatzianestis (2012) reported that the current site receives the impact of human activities, the fish-mussel farm is located to a close gulf (Gulf of Kontinova) which is far away from any human activities and is characterized by negligible levels of inorganic and organic pollution (Banakou and Dailianis, 2010;Chatziargyriou and Dailianis, 2010;Giannapas et al, 2012;Kalpaxis et al, 2004). The collected mussels were transferred to the laboratory and maintained for 7 days in static tanks, containing re-circulated UV-sterilized and filtered artificial seawater (ASW; pH 7.9 AE 0.4, salinity 36 AE 1&, temperature 15 AE 1 C, dissolved oxygen 7 AE 0.5 mg L À1 ), with a 14:10 h light: dark photoperiod, in order to be acclimated in laboratory conditions.…”