Polycyclic aromatic hydrocarbons (PAHs) in the polychaete Sabella spallanzanii, as a reliable bioindicator, by GCMS

Abstract

Every year 230.000 tons of PAHs enter the marine environment, resulting ubiquitously distributed worldwide. These compounds are aromatic molecules of special concern because of their toxic and carcinogenic properties. As a consequence of their hydrophobic nature, in aquatic environments, PAHs rapidly tend to associate with particulate matter and sediments represent the most important reservoir. In the present study the level of PAHs in the sessile filter-feeder polychaete Sabella spallanzanii was assessed. In particular, the concentration of PAHs was determined in polychaetes (body and tube) collected from three Sicilian areas, subject to different anthropic pressure. A transplanting experiment was also performed. Organisms were transplanted from less contaminated to more contaminated site and viceversa. The sample of body and tubes worms was extracted in Automatic Soxhlet with dichloromethane:pentane 1:1 (v/v) following Soxhlet warm mode. At the start and at the conclusion of the experiment all organisms were analysed for PAHs concentrations using a GC-MS. The total concentration of compounds investigated in the tubes of S. spallanzanii expressed as the sum of concentrations varies from 501 to 20304 μg/Kg of dry matrix, while in the bodies, PAHs concentrations ranged from 428 to 3661 μg/Kg of dry matrix.The results showed differences in concentration of PAHs between transplanted and control organisms. Different enzyme response was observed in the organisms transplanted in the most contaminated site, probably as a consequence of different contamination exposures. We conclude that AChE and GST can be used in this species as an early warning system for pollution. These results have implications for the role and possible use of this polychaete as a bioindicator.