Southern Mediterranean coast pollution: Long-term assessment and evolution of PAH pollutants in Monastir Bay (Tunisia)

In order to evaluate the long-term pollution level(s) of Monastir Bay (Tunisian-Mediterranean coastal area), four sediment cores were collected from the meeting points between the main local streams and the marine environment and investigated. Macroscopic observations and granulometric and chemical compositions showed that this Bay received heterogeneous materials. The distribution of 15 total PAH (priority pollutants) concentrations in different levels of core sediments ranged from 222 to 2992 mu g kg-1. Thus, the Bay had been polluted for a long time, and sediments and pollutants had varied anthropogenic sources. After that, local hydrodynamism controlled their distributions. Molecular-weight Polycyclic Aromatic Hydrocarbons (PAHs) and calculated LMW/ HMW ratios showed that pollutants were principally a mixture of pyrolytic and petrogenic sources. One part of these pollutants had local origins, and the most important amounts were of distant origins. Monastir Bay was considered a moderate to highly polluted area, and sediments had an ecosystem risk.

Automated summary

The study on sediment cores from Monastir Bay revealed a long-term pollution with diverse anthropogenic sources. Local hydrodynamics played a role in controlling the distribution of pollutants, predominantly a mixture of pyrolytic and petrogenic sources. The Bay was considered to be a moderately to highly polluted area with potential ecosystem risks.