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Metal(loid) contamination of soil, resulting from the mining activities, is a major issue worldwide, due to its negative effects on the environment and health. Therefore, these contaminated soils need to be remediated. One realistic method is the assisted phytostabilization, which aims at establishing a vegetation cover on the soil that will reduce metal(loid) bioavailability and spreading through the prevention of wind erosion and water leaching. In addition, amendments are applied to improve soil conditions and ameliorate plant growth. In this goal, biochar and compost showed good results in terms of amelioration of soil fertility and reduction in lead bioavailability. However, they usually have a negative effect on arsenic. On the contrary, iron sulfate showed capacity to reduce arsenic mobility through interaction with its iron hydroxides. Finally, the choice of the appropriate plant species is crucial for the success of assisted phytostabilization. One good option is to use endemic species, adapted to the metal(loid) stress, with a fast growth and large shoot and root systems. The aims of this study were to (1) evaluate the effects of applying biochar, compost and iron sulfate, alone or combined, to a former mine soil on the soil properties and Agrostis capillaris growth, and (2) assess the difference between two Agrostis capillaris ecotypes, an endemic metallicolous ecotype and a non-metallicolous ecotype. Results of the mesocosm experiment showed that amendment application improved soil properties, i.e., reduced soil acidity, increased nutrient availability and lower metal(loid) stress, the best being the combination biochar-compost-iron sulfate. These ameliorations allowed a better plant growth. Finally, the metallicolous ecotype performed better in terms of growth than the non-metallicolous one and could thus be used in an assisted phytostabilization process on the former mine site.

The assimilation efficiency of Pb was measured in the candidate sentinel Cantareus aspersus, to assess its capacity to consistently represent the bioavailability of Pb. Three populations were compared from habitats with different levels of toxic and essential metals. For each, 36 snails were fed a laboratory diet with known concentrations of Pb, Ca and Mg over 64 days. Lead bioavailability was measured as the percentage assimilation by the soft tissues (mass in tissues as a fraction of that consumed), and its variation was assessed between populations, exposure periods, dietary Mg and replicates. The indicated bioavailability was consistent over time and Pb consumed, but differed between populations and diets. Population differences were due, in part, to their different growth rates: soft tissue growth was positively correlated with Pb mass and, in the most rapidly growing populations, this accounted for more than 40% of the variation in soft tissue Pb. Populations did not differ in their consumption of Pb, but the highest Mg diet induced higher food consumption and a reduced assimilation of Pb. Tissue growth determines retention and contributes to the variation in the bioavailability indicated by these populations, as do essential metals in the diet. Such variability has important implications for monitoring programmes using resident populations of sentinels to map the bioavailability of toxic metals or integrate a pollution signal over time., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Ingestion of dust or soil particles could pose a potential health risk due to long-term metal trace element (MTE) exposure. Twenty-seven urban topsoil samples (kitchen garden and lawn) were collected and analyzed for Cd, Pb and Zn using the unified Bioaccessibility Research Group of Europe (BARGE) method (UBM) test to estimate the human bioaccessibility of these elements. The quantities of Cd, Pb and Zn extracted from soils indicated, on average, 68, 62 and 47% bioaccessibility, respectively, in the gastric phase and 31, 32 and 23% bioaccessibility, respectively, in the gastro-intestinal phase. Significant positive correlations were observed between concentrations extracted with UBM and total MTE contents. Stepwise multiple regression analysis showed that human bioaccessibility was also affected by some physico-chemical soil parameters (i.e. total nitrogen, carbonates, clay contents and pH). The unified test presents some valuable data for risk assessment. Indeed, the incorporation of oral bioaccessible concentrations into risk estimations could give more realistic information for health risk assessment.

The bioavailability of Cd, Cu, Pb and Zn was assessed in different harbours of the Atlantic coast (France). The responses of the two dominant meiobenthic groups (nematodes and copepods) to a heavy metal contamination gradient measured in similar subtidal sediments were observed in field surveys. Heavy metal concentrations were measured in nematodes and copepods. Nematodes have higher Cd, Cu, Pb and Zn transfer factors than copepods or other benthic species. The flux of heavy metal through nematodes was estimated and appears to be important compared to plankton in the process of heavy metal transfer to benthic or pelagic food webs.

Fungi sampled in three areas in France were analyzed by gamma-spectrometry for their concentrations of 134Cs, 137Cs, 210Pb and 226Ra. In most of the samples radioactive cesium was detected with a maximum of 2860 Bq kg-1 (dry wt.). Activity concentrations of 210Pb were in the range < 1.76-36.5 Bq kg-1 (dry wt.). Activity concentrations of 226Ra were consistently lower, often by one order of magnitude. Models are developed to estimate the contributions of atmospheric 210Pb deposited onto the fruit bodies to the measured 210Pb concentrations and of the uptake of 222Rn soluted in soil pore water which subsequently decays into 210Pb. It is shown that both pathways are of only minor importance. Comparison with the soil-mushroom concentration ratios of stable lead, which were determined for some of the samples, confirmed that 210Pb in mushrooms mainly originates from direct uptake of 210Pb present in the soil. Despite of the high concentrations of 137Cs detected in most of the mushrooms, radiation doses to individuals due to mushroom consumption are dominated by 210Pb for the majority of the edible mushrooms sampled.

This study investigates the relationship among lead exposure (shot ingestion), current lead impregnation (liver lead values), current and previous lead impregnation (bone lead values), and lead excretion (feather lead) in nine species of waterbird from the Camargue (Rhone river delta), France. Results indicate that for individuals there is no readily predictable relationship between ingested shot and liver or bone lead concentrations. However, at the "population" level, and interspecifically, significant positive relationships exist between the susceptibility to shot ingestion and the degree of lead impregnation. Shoveler (Anas clypeata) proved to be an exception, with a high level of shot ingestion and no elevated tissue lead values. This is probably related to dietary factors. Species with a high degree of current lead contamination tended to be those that had also previously absorbed elevated levels of lead. Feather lead concentrations were not clearly related to the vulnerability of a species to shot ingestion or lead poisoning. There was no significant absorption of arsenic and antimony from gunshot associated with lead absorption.