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The concentrations of lead, copper, cadmium, zinc, nickel and chromium were measured in road dust and roadside soils from a French major highway. The profiles of total levels in the soil as a function of distance from the road edge and as a function of depth were investigated. Lead, zinc, copper and, to a lesser extent, cadmium contamination were found in samples taken on the surface and in the immediate vicinity of the road. The observed concentrations decreased rapidly with distance and depth. Soil samples appeared to exhibit little nickel and chromium pollution. The geochemical phases on which heavy metals (lead, copper, zinc, cadmium and chromium) were fixed preferentially, as well as the potential mobility of the different metals under certain physical and chemical conditions were evaluated. Sequential extractions and single extractions with different reagents were performed. Chromium, which was present mostly in residual form, was mainly of natural origin in the studied samples and was not highly mobilisable. Cadmium was the most easily exchangeable element in case of variations in the physical and chemical conditions but the quantities involved remained small. Lead and copper did not appear to be highly mobile. Only drastic conditions, such as those that may be produced by accidental spillage of a chemical product (acid or complexing agent), mobilised them quantitatively. A significant risk of mobilisation was to be feared only in the case of zinc, which is very sensitive to acid pH.

Abstract. The influence of car transport on the sanitary state of the soils is the subject of numerous investigations, carried out in various regions of the world, including Poland. The purpose of the study here presented was to determine the content of the heavy metals (Ni, Pb, Cu, Zn, Cd, and Cr) in the soils of the areas situated along the roads, characterised by different intensities of traffic, different throughput capacities and smoothness of car traffic flow, as well as different road qualities. Investigations have been carried out in various regions of Poland, in the vicinity of the national roads, expressways, as well as motorways. The samples were collected along the transects, located perpendicularly to the road edge, at distances of 1, 3, 5, 10, 20, 50, and 100 metres from the road edge. The analysis of the results obtained allowed for the formulation of the following conclusions: the differences as to the heavy metal content in the soils between the particular segments analysed reach the ratio of over 100 times; the decrease of heavy metal content in the soils follows the distance away from the road towards the open space, and is characterized by a more regular distribution in the case of the areas along the national roads and less regular in the case of areas along the motorways; with similar intensities of traffic, the impact of the motorways on the environment is decidedly lower than of the national roads.

Cyanobacteria are known to produce a wide array of metabolites, including various classes of toxins. Among these, hepatotoxins (Microcystins), neurotoxins (Anatoxin-A and PSP toxins) or cytotoxins (Cylindrospermopsins) have been subjected to numerous, individual studies during the past twenty years. Reports of toxins co-occurrences, however, remain scarce in the literature. The present work is an inventory of cyanobacteria with a particular focus on Nostocales and their associated toxin classes from 2007 to 2010 in ten lakes used for drinking water production in France. The results show that potential multiple toxin producing species are commonly encountered in cyanobacteria populations. Individual toxin classes were detected in 75% of all samples. Toxin co-occurrences appeared in 40% of samples as two- or three-toxin combinations (with 35% for the microcystins–anatoxin combination), whereas four-toxin class combinations only appeared in 1% of samples. Toxin co-occurrences could be partially correlated to species composition and water temperature. Peak concentrations however could never be observed simultaneously and followed distinct, asymmetrical distribution patterns. As observations are the key for preventive management and risk assessment, these results indicate that water monitoring should search for all four toxin classes simultaneously instead of focusing on the most frequent toxins, i.e., microcystins.