Cadmium, manganese, nickel and lead contents in surface sediments of the lower Ulla River and its estuary (northwest Spain)

The authors determined the total contents of cadmium, manganese, nickel and lead in 16 surface sediment samples along the last 7 km of the Ulla River and in its estuary. Prior to chemical analysis, the grain-size fractions below 500, 63 and 2 μm were separated. The metal concentrations were analysed in the fraction below 63 μm, and in selected samples from the clay fraction ( 2 μm). The soil samples were digested with a HF + HNO₃ + HCl mixture and the total concentrations of Cd, Mn, Ni and Pb were analysed with the AAS method. The highest contents of metals were found in the riverine sediments, near the town of Padrón, and in the estuary. The enrichment of metals in the sediments was mainly related to the proximity of the industrial sources, and to the fine particles transported and deposited in the sediments. The Ni and Mn contents found are considered very high, at some points reaching values of up to 357 mg kg⁻¹ and 2 110 mg kg⁻¹, respectively. Lead and Cd were mainly found within the range considered as natural background levels in the sediments of the Galician rias, with concentrations of 25-68 mg kg⁻¹ for Pb and 0.01-0.92 mg kg⁻¹ for Cd. The lower part of the Ulla River and its estuary present: l) moderate to high contamination levels of Mn and Ni; 2) moderate Pb pollution levels; and 3) no Cd contamination. The highest concentrations of metals were obtained in the river, near the wastewater discharges, and in the estuary, associated with fine particles.El contenido total de cadmio, manganeso, níquel y plomo se determinó en 16 muestras de sedimentos superficiales a lo largo de los últimos 7 km del río Ulla y en su estuario. Previamente a los análisis químicos, se realizó la separación granulométrica de los sedimentos en las fracciones inferiores a 500, 63 y 2 μm. La concentración de metales se determinó en la fracción inferior a 63 μm y, para algunas muestras, en la fracción arcilla ( 2 μm). La digestión del sedimento se realizó en una mezcla ácida de HF + HNO₃ + HCl y se analizó la concentración total de Cd, Mn, Ni y Pb por espectroscopia de absorción atómica. Los contenidos más altos en metales se encontraron en los sedimentos del río, en las inmediaciones de Padrón y en los del estuario. El enriquecimiento de los sedimentos en metales se ha relacionado con la proximidad a las zonas industriales y con el material fino transportado y depositado en los sedimentos. Se han encontrado contenidos muy altos de Ni y Mn con valores de 357 mg kg⁻¹ y 2 110 mg kg⁻¹, respectivamente. Las concentraciones de Cd y Pb son comparables a los valores establecidos como niveles naturales en los sedimentos de las rías gallegas: 25-68 mg kg⁻¹ para el Pb y 0.01-0.92 mg kg⁻¹ para el Cd. El sedimento de la parte baja del río Ulla y su estuario presentan niveles moderados-altos de contaminación para Mn y Ni, moderados para Pb y nulos para Cd. Las mayores concentraciones de estos metales en el sedimento fueron medidas asociadas con las fracciones finas ( 63 μm): cerca de Padrón, zona de influencia fluvial y, también, aunque con valores más bajos, en la desembocadura del Ulla, zona de influencia marina.Instituto Español de Oceanografí

Concurrent sampling of transitional and coastal waters by Diffusive Gradient in Thin-films (DGT) and spot sampling for trace metals analysis

This protocol was developed based on the knowledge acquired in the framework of the Interreg MONITOOL project (EAPA_565/2016) where extensive sampling campaigns were performed in transitional and coastal waters covering eight European countries. It provides detailed procedures and guidelines for the sampling of these waterbodies by concurrent collection of discrete water samples and the deployment of Diffusive Gradient in Thin-films (DGT) passive samplers for the measurement of trace metal concentrations. In order to facilitate the application of this protocol by end-users, it presents steps to follow in the laboratory prior to sampling campaigns, explains the procedures for field campaigns (including in situ measurement of supporting parameters) and subsequent sample processing in the laboratory in preparation for trace metal analyze by inductively coupled plasma-mass spectrometry (ICP-MS) and voltammetry. The protocol provides a systematic, coherent field sampling and sample preparation strategy that was developed in order to ensure comparability and reproducibility of the data obtained from each project Partner in different regions. • Standardization of the concurrent sampling of transitional and coastal waters by DGT passive samplers and spot sampling. • Robust procedures and tips based on existing international standards and comprehensive practical experience. • Links to demonstration videos produced within the MONITOOL project

Assessing variability in the ratio of metal concentrations measured by DGT-type passive samplers and spot sampling in European seawaters

The current study evaluates the effect of seawater physico-chemical characteristics on the relationship between the concentration of metals measured by Diffusive Gradients in Thin films (DGT) passive samplers (i.e., DGT-labile concentration) and the concentrations measured in discrete water samples. Accordingly, Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used to measure the total dissolved metal concentrations in the discrete water samples and the labile metal concentrations obtained by DGT samplers; additionally, lead and cadmium conditional labile fractions were determined by Anodic Stripping Voltammetry (ASV) and total dissolved nickel was measured by Cathodic Stripping Voltammetry (CSV). It can be concluded that, in general, the median ratios of DGT/ICP and DGT/ASV(CSV) were lower than 1, except for Ni (median ratio close to 1) and Zn (higher than 1). This indicates the importance of speciation and time-integrated concentrations measured using passive sampling techniques, which is in line with the WFD suggestions for improving the chemical assessment of waterbodies. It is the variability in metal content in waters rather than environmental conditions to which the variability of the ratios can be attributed. The ratios were not significantly affected by the temperature, salinity, pH, oxygen, DOC or SPM, giving a great confidence for all the techniques used. Within a regulatory context such as the EU Water Framework Directive this is a great advantage, since the simplicity of not needing to use corrections to minimize the effects of environmental variables could help in implementing DGTs within monitoring networks

Harmful Elements in Estuarine and Coastal Systems

Estuaries and coastal zones are dynamic transitional systems which provide many economic and ecological benefits to humans, but also are an ideal habitat for other organisms as well. These areas are becoming contaminated by various anthropogenic activities due to a quick economic growth and urbanization. This chapter explores the sources, chemical speciation, sediment accumulation and removal mechanisms of the harmful elements in estuarine and coastal seawaters. It also describes the effects of toxic elements on aquatic flora and fauna. Finally, the toxic element pollution of the Venice Lagoon, a transitional water body located in the northeastern part of Italy, is discussed as a case study, by presenting the procedures adopted to measure the extent of the pollution, the impacts on organisms and the restoration activities

Chemical forms of heavy metals in surface sediments of the San Simón inlet, Ría de Vigo, Galicia

The surface sediments of the San Simon inlet of the Ria de Vigo in Galitia, north‐west Spain contain heavy metal concentrations largely within the range to be expected if these metals were derived from detrital inputs from soils and weathered granitic rocks. Thus, Cu ranged from 24–48 μg g−1 Cr from 37–69 μg g−1, Cr from 0.1–0.5 μg g−1, Ni from 12–29 μg g−1 and Zn from 71–151 μg g−1 of sediment. For Pb, however, the range was 84–394 μg g−1 of sediment which is well above the level which would be expected as background, indicating the likelihood of anthropogenic inputs. Sequential fractionation indicates that relatively high proportions (40%) of this Pb are associated with the oxide and carbonate fractions and may, therefore, be potentially mobile. In contrast, Cr and Ni are found largely in the residual fractions (72 and 65%), whereas Cu is mainly associated with the organic/sulphide fraction (58%). The distribution of Zn is somewhat similar to that of Pb. There is little evidence that diagenetic processes have significantly affected the various metal forms in the sediments with the possible exception of the sites closest to the sea.21 páginasPeer reviewe

Distribution of mercury and other trace metals in the cockle Cerastoderma glaucum from the Mediterranean Lagoon Etang de Thau

8 páginas, 7 figuras, 2 tablasThe concentrations of Ag, Cd, Co, Cr, Cu, Ni, Pb, Zn, Mn, and Fe in the soft tissue of the cockle Cerastoderma glaucum from six sites along the Mediterranean Lagoon Etang de Thau were determined by AAS; Hg was determined by the cold-vapor technique. Significant spatial variations in metal concentrations within the lagoon were recorded. Elevated levels of tissue Pb, Cr, and Hg in the Etang des Eaux Blanches, an area adjacent to the harbor and highly industrialized region, are likely of anthropogenic origin. Seasonally dependent variations in the tissue concentrations of trace elements at Crique de l’Angle were observed. The highest levels of Cr and Pb in the tissue were identified in March 1992, of Hg, Co, and Fe in period August 1990–January 1991, of Mn in August 1992, and Ag in January 1991. The gills contained the maximum amounts of Co and Ni, the mantle the most Fe and Hg, and the digestive gland (hepatopancreas) had most Cu.One of the authors (P.S.) wishes to thank the Embassy of France, which founded his scientific stay in France (IFREMER). This work was carried out within the framework of the Polish-French cooperation program (ATP E01) and was supported by French Government Postdoctoral Fellowship (to M.W.) and by a grant (to P.S.) from the Polish National Committee of Scientific Research (Komitet Badan Naukowych) in Warsaw as part of the LOICZ Programme: grant no. 6 P202 034 06.Peer reviewe

Surveillance des métaux dans les eaux de surface : exercice d'intercomparaison in-situ sur les échantillonneurs passifs

[Departement_IRSTEA]Eaux [TR1_IRSTEA]BELCAIn the context of the Marine Strategy Framework Directive and the Water Frame Work Directive, the chemical monitoring of marine and fresh waters has become a crucial point. Thus, there is a need to apply monitoring methods in surface waters taking into account temporal and spatial aspects with a limited cost and a relatively ease of use by non-expert routine laboratories. Since the 1990’s, passive samplers (PSs) have been widely developed to measure contaminants in surface waters. These tools present many advantages since they allow to (i) give an integrated measure of the contamination over the period of deployment, (ii) avoid problems of contamination linked to sampling procedure via bottles and/or pre-treatment of the sample, (iii) preconcentrate pollutants inducing a decrease of limit of quantification and (iv) avoid complex matrix such as saline waters representing problems for analysis. Nevertheless, there is still a lack of quality assurance and control procedures to improve the reliability and the comparability of results obtained by passive sampling (PS). Indeed, very few in situ intercomparison exercises on PSs have been performed until now. In 2010, an AQUAREF in situ intercomparison exercise that included several types of passive samplers for priority pollutants (PAH, pesticides and metals) was conducted in French surface and coastal waters. This first trial allowed to evaluate the representativeness of different tools for in situ monitoring and showed that despite various strategies and various tools, global uncertainties were generally low and satisfying (Miege et al., 2012). This presentation focuses on the results obtained for the monitoring of metals via PSs during this intercomparison exercise. Two trials were conducted over 7 days periods in the Rhône River at Ternay and in the Thau Lagoon. Ten and six laboratories participated to the trials at Ternay and Thau sites, respectively. Results were reported for eight metals (Cd, Cr, Cu, Ni, Pb, Zn, Mn and Co). Mainly DGT open pores, as well as DGT restricted pores and Chemcatcher® were exposed. We studied more precisely the interlaboratory variability at each step of the DGT deployment and analysis for the determination of a time weight average concentration (TWAC). Thus, results of laboratory and field blanks, reference solutions, and calculation methods were explored to identify parameters influencing the variability of metal TWAC measurements. This enables us to define the main recommendations for the use of PSs by routine laboratories

Surveillance des métaux dans les eaux de surface : exercice d'intercomparaison in-situ sur les échantillonneurs passifs

[Departement_IRSTEA]Eaux [TR1_IRSTEA]BELCAIn the context of the Marine Strategy Framework Directive and the Water Frame Work Directive, the chemical monitoring of marine and fresh waters has become a crucial point. Thus, there is a need to apply monitoring methods in surface waters taking into account temporal and spatial aspects with a limited cost and a relatively ease of use by non-expert routine laboratories. Since the 1990’s, passive samplers (PSs) have been widely developed to measure contaminants in surface waters. These tools present many advantages since they allow to (i) give an integrated measure of the contamination over the period of deployment, (ii) avoid problems of contamination linked to sampling procedure via bottles and/or pre-treatment of the sample, (iii) preconcentrate pollutants inducing a decrease of limit of quantification and (iv) avoid complex matrix such as saline waters representing problems for analysis. Nevertheless, there is still a lack of quality assurance and control procedures to improve the reliability and the comparability of results obtained by passive sampling (PS). Indeed, very few in situ intercomparison exercises on PSs have been performed until now. In 2010, an AQUAREF in situ intercomparison exercise that included several types of passive samplers for priority pollutants (PAH, pesticides and metals) was conducted in French surface and coastal waters. This first trial allowed to evaluate the representativeness of different tools for in situ monitoring and showed that despite various strategies and various tools, global uncertainties were generally low and satisfying (Miege et al., 2012). This presentation focuses on the results obtained for the monitoring of metals via PSs during this intercomparison exercise. Two trials were conducted over 7 days periods in the Rhône River at Ternay and in the Thau Lagoon. Ten and six laboratories participated to the trials at Ternay and Thau sites, respectively. Results were reported for eight metals (Cd, Cr, Cu, Ni, Pb, Zn, Mn and Co). Mainly DGT open pores, as well as DGT restricted pores and Chemcatcher® were exposed. We studied more precisely the interlaboratory variability at each step of the DGT deployment and analysis for the determination of a time weight average concentration (TWAC). Thus, results of laboratory and field blanks, reference solutions, and calculation methods were explored to identify parameters influencing the variability of metal TWAC measurements. This enables us to define the main recommendations for the use of PSs by routine laboratories