# Assessment and Review of Heavy Metals Pollution in Sediments of the Mediterranean Sea
## 3 Results and Discussion
### Comparing Major Heavy Metals Trap Regions: Connections Evidence  
In the studied Mediterranean regions, slight variations exist in the distribution of heavy metal concentrations. The general trend indicates elevated pollution near discharge points (outfalls or spillways), decreasing towards the open sea. While some samples exhibit lower contaminant concentrations, they remain significantly higher than background values from regional indices. As, Ni, and V show a moderately homogeneous spatial pattern with moderate values, while Cu, Hg, and Pb concentrations are exceptionally high around wastewater discharge points, surpassing background values by several orders of magnitude. The distribution of pollution in the Mediterranean Sea demonstrates high agreement (Figures 5 and 6). This clear correlation is because zones near the coast in densely populated areas are points where poorly purified waters with high concentrations of heavy metals are discharged into the sea. Moreover, because the cause of most pollution appears to be common, some heavy metals seen in higher concentrations are common between these areas. Occasionally, certain regions in southern Italy and northern Greece show anomalously high concentrations in some heavy metals, which are attributed to discharges from the metallurgical or mining industry [24]. Most areas with significant pollution values are linked to poorly treated wastewater discharges near the coast, particularly in regions experiencing seasonal overpopulation during Mediterranean summers. Increased tourist pressure in these areas renders it challenging to treat the water consumed by visitors. As depicted in Figure 5, the distribution and concentration of Cu, Pb, Hg, and Zn in the central-northern Mediterranean reveal a similar spatial pattern, with the highest values near coastal areas where wastewater discharges occur. The current results and the statistical treatment revealed that the marine sediments studied in different areas of the Mediterranean Sea present high concentrations of common metals such as Cu, Pb, Zn or Cd. The analogous enrichment of these heavy metals in southern Italy, eastern and southern Italy, Spain, and Greece indicated the existence of a common and main anthropogenic source of these elements. Other areas of Mediterranean  
Figure 4: PCA loading plot for the studied heavy metals in the southwest of Mallorca. PC1 and PC2 account for 3.76% and 19.72% of the variance, respectively. Sea, or even in other parts the world such as southern China or southwestern Turkey [4; 38], show a similar pattern, with high values of heavy metals in coastal areas of highly populated cities. Although the values of these metals may vary between the areas studied, the sequence, from highest to lowest presence, is usually similar between them. For example, the order in southeast China is Cu, Pb, and Zn. In Turkey, Cu and Pb are among the four most enriched metals. The statistical analyses of different regions confirm results that support the thesis of this article, showing that spatial patterns of concentration and sequences of heavy metals is similar to those mentioned. These aspects show how specifically the high concentrations of metals and metalloids are close to the submarine outfalls. Thus, is important in the possible application of active methods to reduce concentration, since the actions can be carried out in more areas that are limited. On the other hand, it is useful for opening new lines of research into chemical vectors that break the balance of the solution and give rise to the chain precipitation of heavy metals in waters that become supersaturated upon contact with the sea water. The chemical relationship between certain elements is crucial to understanding the wide variety of metals deposited in marine sediments, specifically in sand grain fraction.