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Despite the key role that areas close to the rivers Cầu and Ngũ Huyện Khê (Bắc Giang Province, Northern Vietnam) play in the socio-economic development of Vietnam, poor information is available on the level of contaminants and their natural backgrounds in local soils and sediments. To partially fill this gap and to take into account for pressures and impacts on different zones and environment types (river sediments, crop fields, family wells, industrial and urban soils), the samples were collected and analyzed for fifteen trace elements at thirty sites distributed over the province. To overcome the lack of information on natural background and to identify the extent of the deviation from natural conditions, we coupled statistical analysis to contamination indices. The multivariate analysis was used to relate sediment chemical composition with a possible alteration from secondary inputs and to highlight those samples that most deviate from the distribution by category and are potentially more problematic. Geoaccumulation indexes and enrichment factors were calculated to discriminate between natural backgrounds and anthropic sources, SQGs were used for a screening evaluation of environmental risk in the study area. Results showed relatively high concentrations, sometimes exceeding international and national guidelines, and local sources could prevail over geogenic origins. Despite its significant natural contribution all over the study area, As evidenced some cases of anthropogenic contamination, similarly to that observed for Cd, Hg, and Zn. Their high concentrations may be a problem for public health, especially when found in family wells.

In order to study the role of sediment re-suspension and deposition versus the role of organic complexation, we investigated the speciation of cadmium (Cd), copper (Cu) and lead (Pb) in samples collected in the Venice Lagoon during several campaigns from 1992 to 2006. The increment in Cd and Pb concentration in the dissolved phases, observed in the central and northern basins, can be linked to important alterations inside the lagoon caused by industrial and urban factors. The study focuses on metal partition between dissolved and particulate phases. The analyses carried out in different sites illustrate the complex role of organic matter in the sedimentation process. While Cd concentration in sediments can be correlated with organic matter, no such correlation can be established in the case of Pb, whose particulate concentration is related only to the dissolved concentration. In the case of Cu, the role of organic complexation remains unclear., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Recently our findings have shown that the integration of the gene coding for the rat gluco-corticoid receptor (GR receptor) in Nicotiana langsdorffii plants induced morphophysiological effects in transgenic plants through the modification of their hormonal pattern. Phytohormones play a key role in plant responses to many different biotic and abiotic stresses since a modified hormonal profile up-regulates the activation of secondary metabolites involved in the response to stress. In this work transgenic GR plants and isogenic wild type genotypes were exposed to metal stress by treating them with 30ppm cadmium(II) or 50ppm chromium(VI). Hormonal patterns along with changes in key response related metabolites were then monitored and compared. Heavy metal up-take was found to be lower in the GR plants. The transgenic plants exhibited higher values of S-abscisic acid (S-ABA) and 3-indole acetic acid (IAA), salicylic acid and total polyphenols, chlorogenic acid and antiradical activity, compared to the untransformed wild type plants. Both Cd and Cr treatments led to an increase in hormone concentrations and secondary metabolites only in wild type plants. Analysis of the results suggests that the stress responses due to changes in the plant's hormonal system may derive from the interaction between the GR receptor and phytosteroids, which are known to play a key role in plant physiology and development., (Copyright © 2013 Elsevier GmbH. All rights reserved.)

Lead (Pb), cadmium (Cd), copper (Cu) and zinc (Zn) have been measured by electrothermal atomic absorption spectrometry in various sections of the 3623 m deep ice core drilled at Vostok, in central East Antarctica. The sections were dated from 240 to 410 kyear BP (Marine Isotopic Stages (MIS) 7.5 to 11.3), which corresponds to the 3rd and 4th glacial-interglacial cycles before present. Concentrations are found to have varied greatly during this 170 kyear time period, with high concentration values during the coldest climatic stages such as MIS 8.4 and 10.2 and much lower concentration values during warmer periods, such as the interglacials MIS 7.5, 9.3 and 11.3. Rock and soil dust were the dominant sources for Pb, whatever the period, and for Zn and Cu and possibly Cd during cold climatic stages. The contribution from volcanic emissions was important for Cd during all periods and might have been significant for Cu and Zn during warm periods.

The more important water masses generated by the interaction of Circumpolar Deep Water and the shelf waters in the western sector of the Ross Sea are characterized for trace element contents. The distribution of cadmium, lead, copper, zinc, iron, manganese and chromium during the austral summer is analysed and discussed according to the physical, chemical and biological processes which affect the composition of the water masses. The Cd concentration is found to have a relative high variability that can be related to biological activity and the water mass age, MCDW presents a mean dissolved concentration (SD) of 0.77 (0.07) nmol kg(-1), while the HSSW and AASW have a mean concentration of 0.63 (0.06) and 0.61 (0.16) nmol kg(-1), respectively. Lead features the typical distribution of a scavenged element with a surface maximum ranging between 22 and 130 pmol kg(-1) decreasing to 11 pmol kg(-1) in deep waters. However, the vertical distribution in the shelf area features a maximum concentration in intermediate/deep waters and we can hypothesize that the distribution may be influenced by more than one source. The surface dissolved concentration of zinc and copper were un-homogeneously distributed, the mean (SD) values were 5.25 (2.92) and 1.99 (1.49) nmol kg(-1) for zinc and copper, respectively and increased with depth for both the elements. We may therefore hypothesize enrichment in the dissolved phase deriving from recycling in deep waters. 95% of the chromium was in dissolved form and showed a superficial depletion; the mean concentrations were 1.6 +/- 0.2 and 2.6 +/- 0.8 nmol kg(-1) for surface and deep waters respectively. The vertical distribution of dissolved manganese was quite homogeneous with a mean concentration 0.96 +/- 0.7 nmol kg(-1). The particulate iron and manganese concentration trends are similar and feature a significant bottom increase implying a significant input from resuspension; the mean concentration of particulate ranged between 1.4 and 7.4 nmol kg(-1) for iron and ranged between 0.072 and 0.29 nmol kg(-1) for manganese.