Sediment pollution: An assessment of anthropogenic and geogenic trace element contributions along the central Algerian coast.

Sediment cores from the central Algerian coast were collected to investigate the distribution, sources and risk of trace metals. The local geochemical background of metals was defined from the core S collected in an uncontaminated area of the coast. The anthropogenic inputs in Algiers Bay elevated Ag, Cd, Pb and Zn concentrations as their maximum were 3.

Occurrence, contamination level and ecological risk assessment of dissolved and particulate trace elements in rivers entering the southwestern Mediterranean Sea.

Metal pollution in rivers should not be overlooked before their entry into the sea. However, there are few studies for estimating such contamination in rivers entering the Algerian coastal waters. Semimonthly quantification of dissolved and particulate metals, near the mouths of two industrial-tainted rivers, El Harrach and Mazafran rivers, was carried out during a period of one year.

Concentrations and transportation of metal and organochlorine pollutants in vegetables and risk assessment of human exposure in rural, urban and industrial environments (Bouches-du-Rhône, France).

The bioaccumulation of metals (As, Cd, Co, Cr, Cu, Ni, Pb, Sb, V, Zn, Al, Fe) and organochlorine compounds (PCDD-Fs and PCBs) was assessed in soils and vegetables of 3 sites of contrasted anthropogenic influence (rural and industrial-urban areas). Cultivated soils in industrial areas exhibited diffuse pollution in organochlorine pollutants (PCBs and PCDD-Fs). The pollutant levels encountered in vegetables were always lower than the EU regulatory or recommended values.

Effects of increasing concentrations of unamended and gypsum modified bauxite residues on soil microbial community functions and structure - A mesocosm study.

Bauxite residues (BR), commonly named red muds, are the saline-sodic waste produced during the extraction of alumina from bauxite. In this study, four kinds of BR were mixed at increasing concentrations with two soils in a mesososm experiment. Unamended BR from Provence (PRO) and Guinea (GUI) bauxite were selected, and Modified Bauxite Residues from PRO and GUI (MBR-PRO and MBR-GUI) were obtained by gypsum application and repeated leaching, in order to reduce their pH, electrical conductivity (EC) and exchangeable sodium percentage (ESP).

Modelling geochemical and kinetic processes involved in lead (Pb) remobilization during resuspension events of contaminated sediments.

The objective of this paper is to present a model simulating and predicting the exchange kinetics of lead (Pb) between contaminated sediments and water during resuspension events potentially occurring in reservoirs. We developed an innovative model that combines thermodynamic speciation of particulate surfaces (oxides and Particulate Organic Carbon (POC)), thermodynamic Pb speciation in water, and kinetic modelling of exchanges between free Pb and particulate sites (i.e.

Differences in bulk and microscale yttrium speciation in coal combustion fly ash.

Coal combustion ash is a promising alternative source of rare earth elements (REE; herein defined as the 14 stable lanthanides, yttrium, and scandium). Efforts to extract REE from coal ash will depend heavily on the location and speciation of these elements in the ash. This study sought to identify the major chemical forms of yttrium (Y), as a representative REE in coal fly ash samples selected from major coal sources in the United States.

Pollution and ecological risk assessment of heavy metals in the soil-plant system and the sediment-water column around a former Pb/Zn-mining area in NE Morocco.

This study discussed the environmental fate and ecological hazards of heavy metals in the soil-plant system and sediment-water column around the former Pb-Zn mining Zeïda district, in Northeastern Morocco. Spatial distribution, pollution indices, and cluster analysis were applied for assessing Pb, Zn, As, Cu and Cd pollution levels and risks. The geo-accumulation index (I) was determined using two different geochemical backgrounds: i) the commonly used upper crust values, ii) local geochemical background calculated with exploratory data analysis.

Diurnal evolution of the temperature sensitivity of CO efflux in permafrost soils under control and warm conditions.

Cryosols contain ~33% of the global soil organic carbon. Cryosol warming and permafrost degradation may enhance the CO release to the atmosphere through the microbial decomposition. Despite the large carbon pool, the permafrost carbon feedback on the climate remains uncertain.

Investigating palygorskite's role in the development of mesothelioma in southern Nevada: Insights into fiber-induced carcinogenicity.

Similar to asbestos fibers, nonregulated mineral fibers can cause malignant mesothelioma (MM). Recently, increased proportions of women and young individuals with MM were identified in southern Nevada, suggesting that environmental exposure to carcinogenic fibers was causing the development of MM. Palygorskite, a fibrous silicate mineral with a history of possible carcinogenicity, is abundant in southern Nevada.

Pleural mesothelioma in New Caledonia: associations with environmental risk factors.

Background: High incidences of malignant mesothelioma (MM) have been observed in New Caledonia. Previous work has shown an association between MM and soil containing serpentinite.

Objectives: We studied the spatial and temporal variation of MM and its association with environmental factors.

XANES evidence for oxidation of Cr(III) to Cr(VI) by Mn-oxides in a lateritic regolith developed on serpentinized ultramafic rocks of New Caledonia.

Although several laboratory studies showed that Mn-oxides are capable of oxidizing Cr(II) to Cr(VI), very few have reported evidence for such a reaction in natural systems. This study presents new evidence for this redox reaction between Cr(III) and Mn-oxides in a lateritic regolith developed on ultramafic rocks in New Caledonia. The studied lateritic regolith presents several units with contrasting amounts of major (Fe, Al, Si, and Mg) and trace (Mn, Cr, Ni, Co) elements, which are related to varying mineralogical compositions.