Hydrocarbon pollution in the sediment from the Jarzouna-Bizerte coastal area of Tunisia (Mediterranean Sea).

This study investigated the presence and origin of hydrocarbon pollution in industrial waste water sediments found near the Jarzouna (Bizerte, Tunisia) oil refinery. Analyses of surface sediments (layer 1) and deep sediments (layer 2) showed that Total Hydrocarbon (TH) concentrations ranged from 602 +/- 7.638 microg/g in layer-1 to 1270 +/- 2.176 microg/g in layer-2. The results suggest that the deeper the sediment, the higher the level of total hydrocarbon found. The sedimentary Non Aromatic Hydrocarbon (NAH) and Aromatic Hydrocarbon (AH) concentrations ranged from 66.22 +/- 1.516 to 211.82 +/- 10.670 microg/g for NAH, and from 13.84 +/- 0.180 to 115.60 +/- 2.479 microg/g for AH. The high variability of these concentrations was associated with the location of the sediment collection sites. Aliphatic biomarker analysis revealed petroleum contamination close to the refinery rejection site, and biogenic sources further away. Petroleum contamination may be associated with increased industrial activity in the area of Jarzouna-Bizerte in the Mediterranean Sea.

New insights into the genetic history of Tunisians: data from Alu insertion and apolipoprotein E gene polymorphisms.

BACKGROUND: Among polymorphisms of non-transcribed DNA sequences and functional genes, those of Alu insertions and that of the APOE gene have been widely used to clarify the degree of genetic relationships between human populations. AIM: APOE gene and eight Alu insertion polymorphisms were investigated in Tunisians and compared with data from neighbour populations in order to gain new insights into the genetic position of Tunisia in the Mediterranean region. SUBJECTS AND METHODS: A total of 121 individuals from the North and Centre-South regions were sampled. RESULTS: No significant genetic differences were found between Tunisians and North Africans when samples representative of wide areas were considered. APOE gene variation seemed slightly less powerful than the Alu polymorphisms in detecting North-South Mediterranean differences. CONCLUSION: North African populations show a substantial degree of genetic homogeneity, which may reflect the similarity of their origins, mainly when samples from large geographical areas are compared. The relative genetic homogeneity of the whole Mediterranean region probably reflects a common origin and/or remarkable levels of gene flow. However, this gene flow has not yet erased the differentiation between the two Mediterranean shores, as revealed by Alu insertion polymorphisms.