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Physical and chemical properties and the total content of potentially toxic metals (PTMs) in waters and soils were studied from the High Moulouya Valley (Morocco) in order to assess the impact of the past mining activity on their quality and to lay the foundations of a potential reclamation of the area. Surface water and groundwater samples were collected from the Moulouya River and mine pit lakes; tailings and soils were sampled inside and outside the mine sites of Ze < da, Mibladen, and Aouli. Both waters and soils were alkaline, due to the limestone environment, and contained Pb and Zn as main metallic contaminants. Pollution levels were highest within the Mibladen mining site, and soil pollution was mainly restricted to the areas where activities of metal concentration were carried out. Tailings and soils from these areas besides Pb and Zn were also polluted by As, Cd, and Cu showing clay fraction highly enriched in metal contaminants. At the time of study, all soils and wastes (including the highly polluted tailings) were in advanced stage of spontaneous herbaceous and arbustive revegetation. It is concluded that, in the High Moulouya Valley, the processes governing PTM transfer from the element-rich sites to the nearby environment are strongly influenced by pH, carbonate content, and semi-arid climate reducing metal mobility from the mining waste impoundments by dissolution. The transfer by wind and water erosion of metal-enriched fine waste particles is likely to be a much more important vector for metal dispersion. In this perspective, among a range of land remediation techniques available, natural and oriented revegetation could represent a low-cost and possible permanent solution

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The Sarno river basin covers an area of 500 km(2) collecting the waters of Solofrana and Cavaiola tributaries. Originally it manly represents a source of livelihood for inhabitants by fishing and transporting goods; currently, the Sarno river, still partially used for irrigation, is affected by an extreme environmental degradation as a result of uncontrolled outflow of industrial waste. Within the framework of a wider geochemical prospecting project aiming at characterizing the whole territory of the Campania region, 89 stream sediment samples with a sampling density of 1 sample per 5 km(2) were collected in the river basin and analyzed by means of inductively coupled plasma-mass spectrometry in order to assess the environmental conditions at a regional scale. A GIS-aided technique, based on both the actual distribution of potentially harmful elements and their regional background values, was used to generate the maps of the contamination factors and of the contamination degrees for As, Cd, Cr, Cu, Hg, Pb and Zn. Furthermore, a factor analysis was performed to assess the nature and the extent of contamination sources for the river sediments. Results showed that the Sarno river basin could be divided in two "environmental status" units: one, low contaminated, corresponding to the hilly and mountain areas, and the second, from moderately to very highly contaminated, corresponding to the economically developed areas of the valley floor characterized by a high population density. This work was developed within a project that aims to investigate the relationships between environmental pollution and human health by analyzing environmental media (stream sediments, water, soil and vegetation) together with human hair of resident population. In this context, the spatial correlation between the extremely compromised environmental conditions of developed areas and the incidence rate of liver cancer in the same area was also explored posing the need of a careful costs/benefits analysis to assess whether the deterioration of the environment, that could adversely affect the conditions of public health, is worth the economic development.

The interface between biological and geochemical components in the surface crust of a saline soil was investigated using X-ray diffraction, and variable pressure scanning electron microscopy in combination with energy dispersive X-ray spectrometry. Mineral compounds such as halite and gypsum were identified crystallized around filaments of cyanobacteria. A total of 92 genera were identified from the bacterial community based on 16S gene pyrosequencing analysis. The occurrence of the gypsum crystals, their shapes and compartmentalization suggested that they separated NaCl from the immediate microenvironment of the cyanobacteria, and that some cyanobacteria and communities of sulfur bacteria may had a physical control over the distinctive halite and gypsum structures produced. This suggests that cyanobacteria might directly or indirectly promote the formation of a protective envelope made of calcium and sulfur-based compounds.

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