Effect of metal accumulation on metallothionein level and condition of the periwinkle Littorina littorea along the Scheldt estuary (the Netherlands)

Metal (i.e. Ag, As, Ca, Cd, Co, Cu, Mn, Pb and Zn) and metallothionein (MT) concentrations in the soft tissue of Littorina littorea were measured along the heavily polluted Western Scheldt (WS) and relatively clean Eastern Scheldt (ES) estuary. Along the WS metal and MT levels in periwinkles reflected the known downstream decreasing pollution gradient. Surprisingly in ES animals As, Mn and Zn concentrations decreased from east to west reflecting past pollution. Compared to the WS metal concentrations of ES periwinkles were significantly lower and both estuaries were maximally discriminated from each other based on their Cd soft tissue concentration using a canonical discriminant analysis. Furthermore, no overall difference was found in MT levels among animals from both estuaries. Using previously obtained condition data (i.e. dry/wet weight ratio and lipid content) the relation between soft tissue metal concentration (i.e. Cd, Cu and Zn) and fitness indicators (i.e. MT and condition data) was examined using a canonical correlation analysis. Periwinkles with a high metal load (i.e. Cd and Zn) also had high MT levels but were in a relatively poor condition.     

Gross fluxes and estuarine behaviour of pesticides in the Scheldt estuary (1995-1997)

As part of the Fluxes of Agrochemicals into the Marine Environment (FAME) project, the gross fluxes of selected pesticides (i.e. the herbicides atrazine, simazine, alachlor and metolachlor, the atrazine degradation product desethylatrazine, the insecticide dichlorvos and the antifouling agent Irgarol 1051) transported by the river Scheldt and the Canal Ghent-Terneuzen were determined from March 1995 through February 1997. In general, the observed temporal trends were related to the application period of the pesticides, except for metolachlor for which elevated concentrations were observed in the winter of 1995-1996. Relatively large gross fluxes were found for desethylatrazine compared with its parent compound. A study on the estuarine behaviour of pesticides showed distinct differences between the compound classes. The mixing plots of the organophosphorus insecticides dichlorvos and diazinon revealed clear evidence of estuarine loss processes which agrees with their low DT50 values reported for water/sediment systems, their relatively high Henry's law constants and, for diazinon, its relatively high Koc value. The mixing plots of the acetanilides alachlor and metolachlor were strongly influenced by an additional direct emission into the estuary, which was evident from a maximum in dissolved concentration near a salinity of 10@1000. An apparent conservative behaviour was observed for the triazine compounds atrazine and Irgarol 1051. This was in contrast to simazine, which showed an apparent non-conservative behaviour. However, the time profiles of the riverine concentrations of simazine did not exclude that the observed curvature was solely caused by estuarine losses; therefore, additional modelling is required. In a follow-up study a suitable hydrological model of the Scheldt estuary was constructed; the results will be presented in a forthcoming paper (Steen, R.J.C.A., Evers, E.H.G., Van Hattum, B., Cofino, W.P. and Brinkman, U.A.Th. Net fluxes of pesticides from the Scheldt estuary into the North Sea: a model approach. Environmental Pollution, submitted.     

Butyltins in shellfish, finfish, water and sediment from the Coos Bay estuary (Oregon, USA)

Butyltin was measured in tissue, water and sediment samples collected throughout Coos Bay estuary between 1986 and 1997. Butyltin-induced shell deformation in commercial oysters prompted this assessment. Butyltins are released from tributyltin oxide (TBTO)-containing boat paint. Clams from three sites contained tributyltin (TBT) levels ranging from 168 to 457 microg/kg in 1992-1994. Consequently, Oregon Health Division (OHD) issued a shellfish consumption advisory in 1995; it was rescinded in 1997 after US Environmental Protection Agency (EPA) revised the TBTO oral reference dose (RfD). The revised RfD changed the tissue screening level from 112 to 1120 microg TBT/kg. Fifty percent of sediment samples collected during 1991-1997 and analyzed for total butyltins (TotBT) exceeded the Puget Sound Dredge Disposal Analysis Screening Level (PSDDA SL) of 73 microg TBT/kg dw. TotBT at three shipyards selected for site assessment by EPA ranged from 24 to 68,613 microg/kg dw. Sediment and tissue butyltins have been decreasing in all but one area of the estuary.     

Conventional and emerging halogenated flame retardants (HFRs) in sediment of Yangtze River Delta (YRD) region,East China

The occurrence and distribution of polybrominated diphenyl ethers (PBDEs) and eleven non-PBDE halogenated flame retardants (HFRs) were investigated through the collection of marine and river sediment from Yangtze River Delta (YRD), East China. Among them, PBDEs, decabromodiphenyl ethane (DBDPE) and 1,2-dibromo-4-(1,2-dibromoethyl)cyclohexane (TBECH) were the three predominant HFRs with the highest detection frequencies in the sediment. Significant correlation between PBDEs and DBDPE indicated that they may have the similar emission sources. The production and use of DBDPE is growing rapidly and comparable concentrations between PBDEs and DBDPE in YRD sediment may suggest that DBDPE will likely become one of the major HFRs emerging in the environment in China. Of the seven detected non-PBDE HFRs, this is the first time that TBECH was reported in the Chinese environment and its predominance and prevalence in the YRD may imply its extensive use in these areas.     

Accumulation of perfluorooctane sulfonate (PFOS) in the food chain of the Western Scheldt estuary: Comparing field measurements with kinetic modeling

The environmentally persistent perfluorooctane sulfonate (PFOS) is a perfluoroalkylated acid (PFA), which has been found to accumulate and biomagnify through food webs all over the world. In the present investigation, the accumulation kinetics of PFOS was explored using the bioaccumulation model OMEGA. As accumulation behavior of PFOS may show similarities to fatty acids as well as to neutral organic compounds, different modeling approaches were used. Accumulation kinetics of PFOS was modeled similar to (1) moderately and (2) highly hydrophobic compounds, (3) metals and (4) as a combination of hydrophobic compounds and metals. Modeled elimination and uptake rate constants were compared to empirical rate constants from literature. Subsequently, model predictions were compared to field-based biota-suspended solids accumulation ratios (BSAF) in the estuarine food chain of the Western Scheldt, The Netherlands. Results show that uptake of PFOS is comparable to moderately hydrophobic compounds and elimination is best described by elimination kinetics of metals. These observations indicate that the accumulation behavior of PFOS is comparable to that of short and medium chained fatty acids.     

PCDD/Fs and dioxin-like PCBs in sediment and biota from the Mondego estuary (Portugal)

The concentrations of 17 polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs), and 12 dioxin-like polychlorinated biphenyls (dl-PCBs) were measured in sediment and key species as an initial investigation on PCDD/Fs and dl-PCBs contamination in the Mondego estuary (Portugal). The results demonstrated that the values of the total PCDD/Fs (∑PCDD/Fs) concentrations were considerably lower than those of the sum of dl-PCBs (∑dl-PCBs) in all the studied samples. Regarding the contribution of individual congeners, OCDD was the predominant PCDD/F and the mono-ortho PCB 118 and PCB 105 were the dominant PCBs in the majority of the samples. Our results suggest that PCDD/Fs and PCBs behave quite differently along the aquatic food web: ∑PCDD/Fs concentrations were lower in higher trophic-level organisms with fish presenting a distinct PCDD/Fs congeners profile; on the contrary, the higher ∑dl-PCBs values were found in upper-level biota, although not exclusively, and quite similar dl-PCBs congener profiles were observed in nearly all the studied species.     

Distribution and ecotoxicity of chlorotriazines in the Scheldt Estuary (B-Nl)

As part of the Endis-Risks project, the current study describes the occurrence of the chlorotriazine pesticides atrazine, simazine and terbutylazine in water, sediment and suspended matter in the Scheldt estuary (B-Nl) from 2002 to 2005 (3 samplings a year, 8 sampling points). Atrazine was found at the highest concentrations, varying from 10 to 736 ng/l in water and from 5 up to 10 ng/g in suspended matter. Simazine and terbutylazine were detected at lower concentrations. Traces of the targeted pesticides were also detected in sediments, but these were below the limit of quantification. As part of an ecotoxicological assessment, we studied the potential effect of atrazine on molting of Neomysis integer (Crustacea:Mysidacea), a resident invertebrate of the Scheldt Estuary and a proposed test organism for the evaluation of endocrine disruption. Following chronic exposure ( approximately 3 weeks), atrazine did not significantly affect mysid molting at environmentally relevant concentrations (up to 1 microg/l).     

The partitioning of alkylphenolic surfactants and polybrominated diphenyl ether flame retardants in activated sludge batch tests

Polybrominated diphenyl ethers and nonylphenol polyethoxylates have been reported to be estrogenic and may enter the aquatic environment through the discharge of treated sewage effluent. Therefore, their fate during wastewater treatment processes is an important factor in determining their environmental impact. Batch tests with activated sludge from a Husmann apparatus were used to determine the effects of physico-chemical properties and sludge characteristics on the partitioning of polybrominated diphenyl ether flame retardants and nonylphenol polyethoxylate surfactants during biological wastewater treatment. Hydrophobic compounds, those with high logK(ow) values, were sorbed more rapidly and to a greater extent to the solid phase than more soluble compounds. For these hydrophobic compounds sorption may become an increasingly important removal mechanism as sludge age and therefore solids content increase. The initial rate of partitioning was greatest for the most hydrophobic compounds but all rates diminished with time as a result of progressive saturation of sorbent binding sites, a reduction of sorbate availability and as a consequence of the system reaching equilibrium. The sorption of polybrominated diphenyl ethers fit Freundlich adsorption isotherms demonstrating generally increasing adsorption capacity and efficiency with increasing hydrophobic nature. A correlation between increasing logK(ow) and increasing organic matter content was also observed for both polybrominated diphenyl ethers and nonylphenol polyethoxylates indicating the organic content of mixed liquor will also be influential in removing compounds during wastewater treatment.     

Organochlorines in different fractions of sediments and in different planktonic compartments of the Belgian continental shelf and the Scheldt estuary

PCB levels in sediments (bulk and fraction <63 microm), suspended matter and zooplankton from the Belgian continental shelf of the North Sea and the Scheldt estuary were evaluated in relation to their organic carbon content, their lipid content and, for sediments, their particle size distribution. PCB accumulation mechanisms are discussed, considering the importance of direct contamination (adsorption onto the cell surfaces, absorption through the cell walls and partitioning into the cell lipids) for suspended matter and sediments, and of indirect contamination through the food for zooplankton. Geographical and seasonal variations are described.     

Distribution of PCDD/Fs and dioxin-like PCBs in sediment and plants from a contaminated salt marsh (Tejo estuary,Portugal)

Concentrations and profiles of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) were investigated in sediment and plants collected from a salt marsh in the Tejo estuary, Portugal. The highest PCDD/F and dl-PCB concentrations were detected in uncolonized sediments, averaging 325.25?±?57.55 pg g^?1 dry weight (dw) and 8,146.33?±?2,142.14 pg g^?1 dw, respectively. The plants Sarcocornia perennis and Halimione portulacoides growing in PCDD/F and dl-PCB contaminated sediments accumulated contaminants in roots, stems, and leaves. It was observed that PCDD/F and dl-PCB concentrations in roots were significantly lower in comparison with stems and leaves. In general, concentration of ΣPCDD/Fs and Σdl-PCBs in H. portulacoides tissues were found to be twofold higher than those in S. perennis, indicating a difference in the accumulation capability of both species. Furthermore, congener profiles changed between sediments and plant tissues, reflecting a selective accumulation of low chlorinated PCDD/Fs and non-ortho dl-PCBs in plants.     

The toxicology of the three commercial polybrominated diphenyl oxide (ether) flame retardants

Three commercial polybrominated diphenyl oxide flame retardants (PBDPO, PBDE) are manufactured: decabromodiphenyl oxide (DBDPO), octabromodiphenyl oxide (OBDPO) and pentabromodiphenyl oxide (PeBDPO). The composition, production volumes, uses and toxicology of the three products differ. In 1999, DBDPO accounted for approximately 82% of the global PBDPO usage. DBDPO has been extensively tested. DBDPO was not acutely toxic, was not irritating to the skin or eye, and did not induce skin sensitization. No evidence of genotoxic effects was detected in the Ames Salmonella, chromosome aberration, mouse lymphoma, or sister chromatid exchange tests. No cytogenic changes were observed in the bone marrow of rats (parents and offspring) undergoing a one-generation reproduction test. DBDPO did not adversely affect development or reproduction in rats. DBDPO's no-adverse-effect-level (NOAEL) in repeated dose studies was > or = 1000 mg/kg body weight. No, equivocal, or some evidence of carcinogenicity, dependent on genus and sex, was found in mice and rats at 2.5% and 5% of the diet administered for 2 years. DBPDO was poorly absorbed from the gastrointestinal tract (< 0.3-2% oral dose), had a short half-life (< 24 h) compared to PCB 153 (only 2% of an oral dose eliminated by rats in 21 days), and was rapidly eliminated via the feces (> 99% in 72 h). In contrast, components of the PeBDPO product were well absorbed and slowly eliminated, OBDPO's effect level in a 90-day study was approximately 100 mg/kg, PeBDPO's no-effect-level (NOEL) in a 30-day study was 1 mg/kg, and OBDPO induced developmental toxicity in the rat. In aquatic species, neither DBDPO nor OBDPO were toxic to aquatic organisms or bioconcentrating. Components of the PeBDPO product bioconcentrated in fish but produced little evidence of adverse effects.     

The recovery of oyster (Saccostrea glomerata) populations in Sydney estuary (Australia)

The current work documented a significant and widespread increase in the abundance of the Sydney rock oyster Saccostrea glomerata, in Sydney estuary (Australia) by undertaking surveys of oyster density in the estuary in 1989 and annually from 1994 to 2006. Oyster density at six control sites located in nearby National Parks unaffected by boating and stormwater discharges were compared to 17 study sites widely distributed within Sydney estuary. No oyster populations were evident in Sydney estuary in 1989; however, by 1994 oysters had colonised areas of the lower and central estuary and by 2002 densities were statistically similar to control sites. The timing of estuary-wide increases in oyster abundance suggests that the partial banning of tributyltin in 1989 for vessels under 25 m long may have played a major role in the increase of S. glomerata in this estuary.     

Characterization of polychlorinated biphenyls and brominated flame retardants in sludge,sediment and fish from municipal dumpsite at Surabaya,Indonesia

We investigated the PCBs, PBDEs and HBCDs contamination in sludge, sediments and fish from various locations including raw leachate pond, leachate treatment plans (LTPs), control wells and reference site at open landfill of municipal dumpsite, Surabaya City, Indonesia. 62 PCBs and 14 PBDEs congeners, and 3 HBCDs isomers were identified and quantified using GC–MS and LC–MS/MS, respectively. Concentration ranges and median (value in parentheses) of PCBs, PBDEs and HBCDs were from not detected (ND) to 60 (3.9) ng g⁻¹ dw, 0.0075 to 45 (4.5) ng g⁻¹ dw and ND to 2.8 (0.052) ng g⁻¹ dw in sludge and sediments, respectively. While in two polled of fish samples were 30–55 ng g⁻¹ lw, 6.6–11 ng g⁻¹ lw and 1.6–3.3 ng g⁻¹ lw, respectively. Among the sampling sites, the highest level of PCBs and PBDEs were detected in sludge from raw leachate pond. However, PCBs and PBDEs levels were showing decreased in LTP-1 that could be due to the bacterial degradation but not in LTP-2, HBCDs were more stable in both LTPs. Levels of PCBs and BFRs in sludge at the present study were lower than those reported in sewage sludge reported from some other countries. PCBs profiles were mainly composed in that order by CB-138, -153, -180, -101, -118 and -28, while by BDE-47, -99, -100, -153, -154 and -28 for PBDEs in sludge, sediments and fish. Profiles of HBCDs were predominantly composed by γ- and α-isomers in sludge and fish, respectively. Debromination, dechlorination, commercial formulations used and congener-specific accumulation of those contaminants are the factors influenced the profiles.     

Measurement of pollution levels of organochlorine and organophosphorus pesticides in water, soil, sediment, and shrimp to identify possible impacts on shrimp production at Jiquilisco Bay

This study aims to identify levels of several organochlorine and organophosphorus compounds in shrimp-raising areas of coastal El Salvador, to assess potential impacts on shrimp growth and survival that hamper the sustainability of aquaculture in the region. The paper reports the current levels of γ-HCH, 4,4'-DDT, 4,4'-DDE, 4,4'-DDD, endrin, dieldrin, heptachlor, parathion, methyl parathion, and etoprophos in soils (depth 20 cm), sediments (depth 5 cm), shrimp (Penaeus sp.), and water of three rearing ponds and also in the sediment (depth 5 cm) and water surrounding those ponds in Jiquilisco Bay. Sampling was carried out during the dry (January-March) and rainy (June-August) seasons of 2008. The presence of pesticides in the samples of water, shrimp, and sediment at shrimp ponds was not detected in either season; however, in soil samples (depth 20 cm) taken from these ponds, heptachlor, endrin, dieldrin, 4,4'-DDD, and 4,4'-DDT were identified at concentrations below the method limit of quantification (LOQ), and 4,4'-DDE was found in a concentration falling in the range from 3.85 to 19.61 ng/g. In samples of water taken at the bay water intakes to the rearing ponds, we observed dieldrin concentrations in the range between 0.085 ng/mL and 0.182 ng/mL during the dry season. In the samples of sediments taken in the surrounding areas of shrimp ponds, we found-for both seasons-that in 60 % of the samples, 4,4'-DDE was present in concentrations ranging from 3.75 ng/g to 30.97 ng/g. Additionally, in the rainy season, we observed heptachlor in sediment at concentrations below the method quantification limit. It was concluded that organochlorine compounds from pesticides are still present in Jiquilisco Bay, trapped in deep sediment, even though they have been banned since the 1980s. These were not detected in shrimp tissue, surface water, and shallow sediment in rearing ponds, and hence, we do not believe their presence has any major impact on shrimp production in sampled areas.     

Tolerance to,and avoidance of,hypoxia by the penaeid shrimp (Metapenaeus ensis)

Aquatic hypoxia caused by eutrophication may lead to mass mortality of valuable living resources such as fish and shrimp. However, there is little information on the hypoxic tolerance of penaeid shrimp, and whether they are able to avoid hypoxia. In laboratory experiments, LC50, LT50 and heart beats per minute were determined for juvenile Metapenaeus ensis at 0.5, 1.0, 2.0 and 6.0 mg O2 l(-1). The 8-h LC50, for DO was 0.77 mg O2 l(-1), while the LT50 at 0.5 mg O2 l(-1) was 399 min. Heart beat rate significantly declined when DO fell below 1.0 mg O2 l(-1). When confronted with a gradient of dissolved oxygen, M. ensis were able to avoid hypoxic areas and move to oxygenated water. M. ensis appeared to be sensitive to hypoxia, and their ability to detect and avoid hypoxia may enhance their survival in habitats where hypoxia may occur.     

Seasonal and spatial distribution of metals in surface sediment of an urban estuary

Aquatic pollution by metals is of concern because of various toxic effects to marine life. The Tolka Estuary, Co. Dublin, Ireland, is a typical Irish urban estuary. It has a significant metal loading originating from the urban environment. Results of a 25month analysis of cadmium, copper, lead and zinc spatial and temporal distribution over 10 sample locations in this estuary are presented in this paper. Metal concentrations were analysed using differential pulse polarography. Significant seasonal and spatial trends in metal distribution were observed over the 25months. Sediment metal concentrations gradually increased (30-120%) in spring to a maximum at the end of summer which was followed by a decrease in winter months (30-60%). Sediment organic matter (OM) concentrations exhibited similar seasonal trends and a positive correlation between OM and metal distributions was observed, implying OM had an influence on metal distributions over time.     

Concentrations of pentachlorophenol (PCP) in fish and shrimp in Jiangsu Province, China

Pentachlorophenol (PCP) concentrations were determined in 55 samples of fish, shrimp, crabs, frogs and turtles collected in Jiangsu Province and 55 freshwater shrimp samples collected from the Huiming Fish Market, Nanjing, China between 2003 and 2004. PCP concentrations ranged from less than the method detection limit (MDL: 0.5 microg/kg ww) to 61 microg/kg ww, with a mean of 5.2 microg/kg ww in 55 samples collected across Jiangsu Province and a mean of 0.5 microg/kg ww for freshwater shrimp collected from the Huiming Fish Market. Concentrations of PCP in common carp (Carassius auratus) were significantly greater than concentrations of PCP in other species from all of the areas studied. Grass carp (Ctenopharyngodon idella) contained the second greatest concentrations and crustacean species contained the least concentrations. Concentrations of PCP were greater in samples collected from Southern Jiangsu than those collected from other areas of Jiangsu Province. Concentrations of PCP in the freshwater shrimp (Macrobrachium nipponense) from the Huiming Fish Market were greater in March and September than those collected in June and December. Based on the allowable daily intake (ADI) set by the US National Academy of Science, current concentrations of PCP measured in aquatic products from Jiangsu Province presented minimus health risks to humans.     

Organochlorinated pesticides, PCBs, dioxins, and PBDEs in grey mullets (Liza ramada) and allis shads (Alosa alosa) from the Vilaine estuary (France)

This study aimed to compare the contamination levels of various organohalogenated compounds in two migratory fish species in the Vilaine River in western France. Organochlorinated pesticides, polychlorinated biphenyls (PCBs), dioxins (polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDDs/Fs)), and polybrominated diphenyl ethers (PBDEs) were analyzed in two diadromous species from the Vilaine estuary, the grey mullet (Liza ramada)—an amphihaline species, and the allis shad (Alosa alosa)—an anadromous species. Fish were collected in spring 2004 and spring 2005, upstream and downstream of the Arzal Dam. PCB contamination varied from 27 to 200 ng?g^?1 dry weight (d.w.). PCDDs/Fs, expressed in toxicity equivalent quantity (TEQ) varied from 0.4 to 2.8 pg?g^?1 d.w. Dioxins and dioxin-like PCBs expressed in total TEQ varied from 1.4 to 18.8 pg?g^?1 d.w. PBDE47 was present at around 2–10 ng?g^?1 d.w. and concentrations of the insecticide dichlorodiphenyltrichloroethane breakdown product p,p′-dichlorodiphenylchloroethylene varied from 1 to 14 ng?g^?1 d.w. For both species, specimens collected upstream were more contaminated. The grey mullet specimens were less contaminated than the allis shad when taken downstream of the dam but were more contaminated upstream. The allis shads presented intermediate contaminant concentrations with a less pronounced difference between upstream and downstream specimens. However, it is thought that shads do not feed when they spawn in the upstream parts of rivers, which should modify the contaminant concentrations. However, measurements in upstream shad samples show an unexpected increase of the contamination, which remains unexplained.     

Maternal transfer of brominated flame retardants in zebrafish (Danio rerio)

In many species reproduction and embryonic development have been shown to be sensitive to environmental contaminants. Understanding embryonic exposure to environmental contaminants is thus highly important. In this study concentrations of brominated flame retardants (BFRs) were measured in zebrafish eggs after parental exposure for 42 days via the diet. Zebrafish were exposed to two doses of eleven structurally-diverse BFRs. Eight BFRs were detected in the female zebrafish and maternal transfer to eggs was evident for all eight compounds. The highest concentrations in eggs were observed for hexabromocyclododecane (HBCD) and 2,4,4'-tribromodiphenyl ether (BDE 28), followed by 2,2',3,4,4',5',6-heptabromodiphenyl ether (BDE 183) and tetrabromobisphenol A 2,3-dibromopropyl ether (TBBPA DBPE). Five potential BFR metabolites were tentatively identified in female fish and maternal transfer was observed also for these compounds. The lipid adjusted concentrations in eggs were significantly higher than the concentrations in female fish for several of the BFRs. Further, the results showed a generally higher transfer in the lower exposure level and also indicated a dependency on the physico-chemical properties of the compounds.     

Temporal-spatial trends in heavy metal contents in sediment-derived soils along the Sea Scheldt river (Belgium)

The aim of this study was to survey the alluvial plains of the Sea Scheldt river in Belgium for the presence of old sediment-derived soils, and to appraise the heavy metal contamination at these sites. Historically, sediments of periodical dredging operations have been disposed in the alluvial plain without concern for the potential presence of contaminants. Up to 96% of the areas that were affected by sediment disposal (ca. 120 ha) was found to be polluted by at least one of the metals Cd, Cr, Zn or Pb. Concentrations of Cd, Cr and Zn were, in 10% of the cases, higher than 14, 1400 and 2200 mg/kg DM, respectively. Based on the Flemish decree on soil sanitation, Cu and Ni concentrations were of less environmental concern on any site. The pollution in the Sea Scheldt alluvial plain nevertheless is lower than for the Upper Scheldt alluvial plain. The sediment-derived soils in the most upstream part near Ghent were used for disposal of sediments from dredging operations elsewhere. Metal concentrations were explored and both spatial and temporal trend were analysed. The pollution levels encountered warrant caution as most of the soils affected by historical dredged sediment disposal are currently in use for pasture.