Occurrence of organochlorine insecticides, PCBs and PCB congeners in waters and sediments of the Ebro River (Spain)

Complex mixtures extracted from air filters exposed for 24 h in two sessions (27 July and 02 August 1991) and at two locations (Merced, downtown, and Pedregal de San Angel, south-west) in Mexico City were analysed. The organic extracts were from airborne particles equal or smaller than 10 microns (PM10), and from total suspended particles (TSP). These organic extracts were assayed in the somatic mutation and recombination test (SMART) in wings of Drosophila melanogaster using two different crosses as well as in the Salmonella/microsome assay using strain TA98 with and without S9 fraction. The presence of polycyclic aromatic hydrocarbons (PAH) in the extracts was determined by gas chromatography. The genotoxic activities observed in the two test systems were comparable with the indirect mutagens producing greater response than the direct mutagens. The quantities of particulate matter as well as the genotoxic activities were higher on 02 August than on 27 July 1991 for both locations. The amounts of airborne particles and the resulting genotoxic activities were higher at Merced than at Pedregal. In both biological systems, PM10 were more genotoxic than TSP. These results demonstrate the sensitivity of the Drosophila wing SMART-which is an in vivo eukaryotic genotoxicity assay-as a biological monitor of environmental pollution related to airborne particles.     

Distribution and biological impact of dioxin-like compounds in risk zones along the Ebro River basin (Spain)

The aim of this investigation was to evaluate the environmental impact associated to PCDDs/Fs and dioxin-like PCBs in the Ebro River basin. Sediments and fish from several species were sampled at three sites with different historical pollution records, including the Barbastro area with different industrial activities, and the Flix and Monzón sites, associated to heavy organochlorine compound pollution. Seventeen toxic PCDDs/Fs and 12 dioxin-like PCBs were analyzed by GC-MS. The results obtained indicated significant accumulation of dioxin-like PCBs, but not PCDDs/Fs, in sediments and fish at the Flix site compared to the other sites. Concomitantly, cytochrome p450 1A (CYP1A) expression, a known indicator for pollution by dioxins and dioxin-like PCBs, was significantly elevated in barbel (Barbus graellsii) from the Flix site, compared to the population from the Barbastro site. CYP1A expression correlated with the concentration of dioxin-like PCBs in the fish fat, whereas no significant correlation was found with PCDDs/Fs concentrations. Our data suggest a significant biological impact at the Flix site, closely related to the presence of dioxin-like PCBs, whereas the PCDDs/Fs contribution to this impact appears to be non-significant, at least in the studied sites.     

Pilot survey of a broad range of priority pollutants in sediment and fish from the Ebro river basin (NE Spain)

Priority organic pollutants were investigated in sediments and fish collected along the Ebro river basin (NE Spain) to evaluate their occurrence, transport and bioavailability. Sediments were collected in 18 sites and two species of fish were captured in nine sites according to the availability in each area. The sampling sites covered industrial, urban and agricultural areas. Four methods were used to detect 20 organochlorine compounds (OCs), 8 polycyclic aromatic hydrocarbons, 3 organotin compounds, 2 alkylphenols and 40 polybrominated diphenyl ethers (PBDEs) from purified extracts. The contamination pattern was site specific and no downstream increase in concentration of pollutants was observed but rather a generalized low level diffuse pollution. Target compounds were detected in sediments at 0.01 to 2331 microg/kg dry weight, and only OCs and PBDEs were accumulated in benthopelagic fish. Toxicological assessment was performed according to predicted environmental levels and revealed sites where adverse effects could occur.     

Spatial variation of DDT and its metabolites in fish and sediment from Cinca River, a tributary of Ebro River (Spain)

The Cinca River is a tributary of Ebro River in the NE of Spain which receives input from different activities. One of the most important is related to an industry where DDT is used as an intermediate in the production of dicofol. This study evaluated the DDT contamination along the Cinca River. Sampling sites were selected up- and downstream from this industry. Sediments and fishes (59 bleaks (Alburnus alburnus) and 23 barbels (Barbus graellsi)) were collected in 2002 and analyzed using a new and rapid selective pressurized liquid extraction (SPLE) method. DDT and its metabolites were found in sediments and fishes at levels ranging from 9 to 94microg kg(-1) dry weight (d.w.) and from not detected to 2098microg kg(-1) wet weight (w.w.), respectively. The highest values corresponded to samples collected just downstream the industry. Thirty kilometers downstream from the factory, levels were clearly lower, showing a weakening of the impact. p,p'-DDE isomer comprised up to 50% and 70% of total DDT measured in sediment and fish, respectively. When compared with values obtained in a previous study in 1999, a generalized drop of the levels in all matrixes (77-97%), was observed. No meaningful differences were found between the two fish species studied neither between the two tissues (muscle and liver) analyzed.     

First evidence of polybrominated diphenyl ether (flame retardants) effects in feral barbel from the Ebro River basin (NE, Spain)

Polybrominated diphenyl ethers (PBDEs) are chemicals of environmental concern due to their lipophilic, persistent and bioaccumulable characteristics as well as for their potential endocrine disrupting role. Former studies carried out in a tributary of the Cinca river (Ebro basin, NE Spain) revealed high levels of PBDEs in fish due to the discharges of effluents rich in PBDEs coming from a nearby industrial park in Barbastro. In this study, several biomarkers of pollutants exposure were measured in barbel, Barbus graellsii, before (upstream) and after (downstream) the main industrial site (Barbastro) in the Vero river. The results evidenced an enhanced hepatic phase I and II metabolism (measured as reductases, glutathione S transferase and uridinediphospho-glucuronosyltransferase), and of the antioxidant enzyme glutathione peroxidase. Conversely, fishes collected from downstream reaches had their phase I CYP1A dependent ethoxyresorufin O-deethylase, antioxidant diaphorase and brain cholinesterase activities depleted. In addition, the histological study of the liver and kidney of these fish evidenced an increase of the number and size of macrophage aggregates in most individuals collected downstream. Bivariate correlated analyses showed that the above mentioned biomarkers were correlated to measured PBDE congeners, thus indicating that the observed biological effects were unlikely to be related to other environmental factors than PBDEs. Overall, the measured biochemical and histological markers provide new evidence that in field exposed fish, PBDEs levels were associated with high activities of phase I and II metabolic enzymes, oxidative stress in liver, neurotoxicity in brain and histopathological effects in both liver and kidney.     

Patterns of mercury and methylmercury bioaccumulation in fish species downstream of a long-term mercury-contaminated site in the lower Ebro River (NE Spain)

Since the 19th century, large amounts of industrial waste were dumped in a reservoir adjacent to a chlor-alkali plant in the lower Ebro River (NE Spain). Previous toxicological analysis of carp populations inhabiting the surveyed area have shown that the highest biological impact attributable to mercury pollution occurred downstream of the discharge site. However, mercury speciation in fish from this polluted area has not been addressed yet. Thus, in the present study, piscivorous European catfish (Silurus glanis) and non-piscivorous common carp (Cyprinus carpio) were selected, to investigate the bioavailability and bioaccumulation capacities of both total mercury (THg) and methylmercury (MeHg) at the discharge site and downstream points. Multiple Correspondence Analysis (MCA) was applied to reduce the dimensionality of the data set, and Multiple Linear Regression (MLR) models were fitted in order to assess the relationship between both Hg species in fish and different variables of interest. Mercury levels in fish inhabiting the dam at the discharge site were found to be approximately 2-fold higher than those from an upstream site; while mercury pollution progressively increased downstream of the hot spot. In fact, both THg and MeHg levels at the farthest downstream point were 3 times greater than those close to the waste dump. This result clearly indicates downstream transport and increased mercury bioavailability as a function of distance downstream from the contamination source. A number of factors may affect both the downstream transport and increased Hg bioavailability associated with suspended particulate matter (SPM) and dissolved organic carbon (DOC).     

Estimating the environmental impact of micro-pollutants in the low Ebro River (Spain): an approach based on screening toxicity with Vibrio fischeri

The aim of this study was to assess the likely impacts on the ecosystems due to agricultural, human, and industrial activities carried out in an ecologically important area of the Ebro River (Spain). For it, a screening site specific ecological risk assessment was conducted. Considering the presence of high levels of potentially toxic substances, such as metals and chlorinated organic compounds, aqueous and organic extracts were used to assess toxicity in sediments by using the photo-luminescent bacteria Vibrio fischeri (Microtox) as screening response variable. Sediment samples collected during 2005-2006 in the last course of the Ebro River and its Delta have been analyzed. Toxic responses have shown strong relationships to the levels of pollutants in the area. Moreover, various sites presented some toxicity level, probably because of other factors associated with reducing environments into the sediments. Results indicate that Microtox bioassay is an appropriate tool to perform risk assessment studies at screening level.     

Polychlorinated dibenzo-p-dioxins,dibenzofurans, biphenyls,paraffins and polybrominated diphenyl ethers in marine fish species from Ebro River Delta (Spain)

The results of a surveillance programme on the determination of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and short chain chlorinated paraffins (SCCPs) in marine fish and shellfish species which are fished, commercialised and consumed in the Ebro River Delta area (NE, Spain) are presented. The study included the analysis of five marine fish species (sardine, gilthead sea bream, conger, eel and flounder) and three shellfish species (murex, carpet shell and mussel) collected in 2012 in five fishing harbours near to this area. WHO-TEQ concentrations for PCDD/Fs and dioxin like PCBs (dl-PCBs) ranged from 0.03 to 0.31 pg WHO-TEQ_2005PCDD/F g⁻¹ wet weight (ww) and from 0.02 to 3.15 pg WHO-TEQ_2005PCB g⁻¹ ww, respectively. All levels were below the maximum concentrations established by the EU Regulation. The PCBs and PCDD/Fs accumulation pattern found in the samples analysed showed a distribution typically reported for marine samples. For marker PCBs and PBDEs, concentration levels ranging from 929 to 57 494 pg g⁻¹ ww and from 36.2 to 827 pg g⁻¹ ww were obtained, respectively, meanwhile for SCCPs levels were between 3.1 and 141 ng g⁻¹ ww. Finally, the trends in the levels of PCDD/F and dl-PCBs found from 2006 to 2012 in fish and shellfish species were studied. A slight decrease of PCDD/F and dl-PCB concentrations was found since 2006.     

Emerging pollutants in sewage, surface and drinking water in Galicia (NW Spain)

A monitoring programme was carried out on wastewater, surface and drinking water on the NW area of Spain during the four seasons of a year period (November 2007-September 2008). This study covered a series of emerging pollutants of different classes, including pharmaceuticals, neutral and acidic organophosphorus flame retardant/plasticizers (OPs), triclosan, phenoxy-herbicides, insect repellents and UV filters. From the total set of 53 compounds, 19 were found in raw wastewater with median concentrations higher than 0.1 μg L⁻¹. Among them, salicylic acid, ibuprofen and the UV filter benzophenone-4 (BP-4) were the most concentrated, exceeding the 1 μg L⁻¹ median value. Subsequently, 11 of these contaminants are not efficiently enough removed in the small WWTPs tested and their median concentrations in effluents still surpassed the 0.1 μg L⁻¹, so that they can spread through surface water. These chemicals are the pharmaceuticals naproxen, diclofenac and atenolol; the OPs tri(2-chloroethyl) phosphate (TCEP), tri(chloropropyl) phosphate (TCPP), tri-n-butyl phosphate (TnBP), diphenyl phosphate (DPhP) and diethylhexyl phosphate (DEHP); and the sulphonate UV filters BP-4 and 2-phenylbenzimidazole-5-sulphonic acid (PBSA). These OPs were then the dominant emerging pollutants occurring in surface and drinking water, where they are detected in the 20-200 ng L⁻¹ range. Pharmaceuticals and UV filters are typically below the 10 ng L⁻¹ level. Finally, herbicides were only detected in the last sampling campaign under the 100 ng L⁻¹ drinking water European Union limit.     

Factors affecting the organochlorine pollutant load in biota of a rice field ecosystem (Ebro Delta, NE Spain)

The concentrations of PCBs, DDTs, HCHs, HCB and OCS were determined in sediments and associated biota, both invertebrates (Physella acuta, Hirudo medicinalis, chironomid larvae, Hydrous pistaceus, Helochares lividus) and vertebrates (Rana perezi), in a temporary aquatic system, a rice field in the Ebro Delta (NE Spain). The qualitative and quantitative distribution of organochlorine compounds in sediments and aquatic biota has been explained by two mechanisms: equilibrium partitioning and/or biomagnification through the trophic web. Nevertheless, bioaccumulation processes are by far more complex, since several biotic and abiotic factors contribute to the observed pollutant loads in the organisms. In this respect, the biological characteristics of the organisms considered (e.g. species, age, lipid contents, feeding habits, etc.), as well as ecological factors (e.g. the habitat of the species and vertical distribution), have been shown to account for the organochlorine levels observed.     

Blood biomarkers and contaminant levels in feathers and eggs to assess environmental hazards in heron nestlings from impacted sites in Ebro basin (NE Spain)

Blood biomarkers and levels of major pollutants in eggs and feathers were used to determine pollution effects in nestlings of the Purple Heron Ardea purpurea and the Little Egret Egretta garzetta, sampled on three Ebro River (NE Spain) areas: a reference site, a site affected by the effluents of a chlor-alkali industry and the river Delta. The two impacted heron populations showed mutually different pollutant and response patterns, suggesting different sources of contamination. In the population nesting near the chlor-alkali plant, elevated levels of hexachlorobenzene (HCB) and polychlorobiphenyls (PCBs) in eggs, and mercury in feathers in A. purpurea chicks were related with reduced blood antioxidant defenses and increased levels of micronuclei. In Ebro Delta, high levels of plasmatic lactate dehydrogenase in A. purpurea chicks and high frequency of micronuclei in blood of both species were tentatively associated with intensive agricultural activities taking place in the area. These results provide the first evidence of a biological response in heron chicks to the release of pollutants at a chlor-alkali plant.     

Analysis of micronucleated erythrocytes in heron nestlings from reference and impacted sites in the Ebro basin (N.E. Spain)

The frequency of micronuclei (MN) in peripheral erythrocytes was tested for 59 heron nestlings (Ardea purpurea, Egretta garzetta and Bubulcus ibis) sampled at two areas (polluted and reference) on the River Ebro (NE Spain) and at its Delta during Spring 2006. Flow-cytometry analysis revealed higher (three- to six-fold) MN counts in samples from the most polluted site relative to samples from the reference area. Samples from the Delta showed intermediate values. Age, morphometric parameters (weight, tarsus size and bill-head length) and maturation status showed no significant differences among the different populations for each species; nor were they correlated with MN levels. The data suggest that elevated levels of MN in chicks in impacted areas reflected the chemical pollution of their nesting sites. The use of nestlings for this assay appears to be a convenient, non-destructive method to assess the impact of pollution in natural bird populations.     

Colloidal mobilization from soil and transport of uranium in (sub)-surface waters

An analytical methodology was developed to characterize the colloidal distribution of trace elements of interest in environmental waters sampled in a same site and enables the different colloidal distributions from waters to be compared. The purpose was to provide consistent information related to the origin and nature of colloids responsible for the transport of trace element(s). The work was motivated by the observed enhanced mobility of uranium in soil. The colloidal size continuum was investigated by a multi-technique approach involving asymmetric flow field-flow fractionation (AF4) coupled with ultraviolet spectroscopy (UV), multi angle light scattering (MALS), and atomic mass spectrometry (ICPMS). To take into consideration the size and shape variability specific to each sample, the size distributions were established from the gyration radii measured from MALS, also considering the size information from standard nanospheres fractionated by AF4. A new parameter called “shape index” was proposed. It expresses the difference in hydrodynamic behavior between analytes and spherical particles taken as reference. Under AF4 diffusion conditions, it can be considered as an evaluator of the deviation from the sphericity of the fractionated analytes. AF4-UV-MALS-ICPMS enabled the dimensional and chemical characteristics of the colloidal size continuum to be obtained. As a “proof of concept”, the developed methodology was applied at a field scale, in a reference study site. In order to have a “dynamic understanding”, the investigation was based on the joint characterization of colloids from surface waters and soil leachates from static and dynamic processes. In the water samples of the study site, the continuum of gyration radius ranged from a few nanometers up to 200 nm. Colloids containing iron, aluminum, and organic carbon were involved in the uranium transport in the soil column and surface waters. The colloidal uranium concentration in the surface water increased from the upstream location (approximately 13 ng (U) L^?1) to the downstream location (approximately 60 ng (U) L^?1).

     

Brominated flame retardants in Alburnus alburnus from Cinca River Basin (Spain)

Thirty-two bleak fish (Alburnus alburnus) from three places along the Spanish River Cinca, a tributary of Ebro River, were collected for polybrominated diphenyl ether (PBDE) and hexabromocyclododecane (HBCD) determinations. Sampling sites corresponded to up- and downstream from Monzon, a heavily industrialized town draining to the river. Four different PBDE congeners (BDE-47, -153, -154 and -183) and HBCD were found at levels ranging from not detected (nd) to 573 ng/g wet weight for total PBDEs and from nd to 1643 ng/g wet weight for HBCD. The lowest values were found upstream of the industrialized area. Concentrations in fish were compared with previous data in sediment samples collected at the same sampling sites, and large fish to sediment ratios for these brominated compounds indicate that they are highly bioavailable. Moreover, PBDE and HBCD concentrations are correlated with fish length and weight indicating the bioaccumulation of these contaminants.     

Organochlorine compounds in common dolphins (Delphinus delphis) from the Atlantic and Mediterranean waters of Spain

Blubber of free-ranging common dolphins (Delphinus delphis) from the northwestern coast of Spain (Atlantic), sampled in 1984 and 1996, and of common dolphins entangled in fishing nets in the southwestern Mediterranean, sampled during 1992 1994, was analysed for organochlorine pollutants. In the Atlantic, concentration of all pollutants was significantly higher in males than in females. The overall tPCB/tDDT ratio in this area was 3.35, which indicates a predominance of industrial inputs over those associated with agriculture. Individuals sampled in 1996 showed significantly lower DDT concentrations but a higher ppDDE/tDDT ratio than those sampled in 1984, which reflects the aging of the environmental load. In the same period, tPCB concentration remained constant and, as a consequence, the tPCB/tDDT ratio more than doubled. In the Mediterranean, the reduced sample size of adult individuals precluded proper statistical investigation of sex-related variation. The overall tPCB/tDDT ratio was 1.12, suggesting a higher contribution of pollutants of agricultural origin. Individuals had significantly higher levels of all DDT forms and a higher ppDDE/tDDT ratio than their counterparts from the Atlantic, but similar PCB concentrations. However, the relative frequency of the different congeners in relation to the total PCB load was different in the two areas. This indicates that the two populations do not mix, at least in the short- or medium-term. Organochlorine levels in both areas are at the mid to low end of the range of concentrations detected in other common dolphin populations and in that of other Delphinidae species from the same region. Although the impact of the organochlorine concentrations on the common dolphin populations surveyed cannot be assessed, it is considered unlikely that they have played a significant role in the decline that the species has suffered in recent decades in the western Mediterranean.     

Spatial distribution and sources of perfluorochemicals in the NW Mediterranean coastal waters (Catalonia, Spain)

This study provides the first evidence of the sources and loads of perfluorochemicals (PFCs) to the NW Mediterranean Sea. Five PFCs were analyzed in 45 seawater samples collected along the Catalan coast. Total PFCs ranged from 0.07 to 13.0 ng/l, being the levels higher in ports than in coastal waters. To determine the sources of PFCs, 8 wastewater treatment plants (WWTPs) effluents and 6 rivers discharging to the sea were also analyzed. WWTP effluents contained total PFCs levels ranging from 3.47 to 132 ng/l but due to the relatively low discharge flows, they contributed to 34.7 g/d to the sea. Total PFCs in rivers ranged from 2.24 to 21.9 ng/l and were the principal PFCs contributors to the sea. Overall, a total load of 190 g/d of PFCs are discharged to the NW Mediterranean coast. The effects and risk of PFCs discharges to the Mediterranean basin are discussed.     

Heavy metals contents in agricultural topsoils in the Ebro basin (Spain). Application of the multivariate geoestatistical methods to study spatial variations

In this work the content of seven heavy metals (Cd, Cr, Cu, Hg, Ni, Pb and Zn) and other parameters (the pH, organic matter, carbonates and granulometric fraction) in agricultural topsoil in the Ebro basin are quantified, based on 624 samples collected according to an 8 by 8 km square mesh. The average concentrations (mg/kg) obtained were: Cd 0.415+/-0.163, Cr 20.27+/-13.21, Cu 17.33+/-14.97, Ni 20.50+/-22.71, Pb 17.54+/-10.41, Zn 17.53+/-24.19 and Hg 35.6+/-42.05 microg/kg. The concentration levels are relatively low in areas of high pH and low organic matter content concentration. The results of factor analysis group Cd, Cu, Hg, Pb and Zn in F1 and Cr y Ni in F2. The spatial heavy metals component maps based on geostatistical analysis, show definite association of these factors with the soil parent material. The local anomalies (found in Cu, Zn and Pb) are attributed to anthropogenic influence.     

Differential accumulation of mercury and other trace metals in the food web components of a reservoir impacted by a chlor-alkali plant (Flix, Ebro River, Spain): Implications for biomonitoring

Comparative studies of biomonitors of trace metal contamination are relatively scarce. We took advantage of a point source pollution in a reservoir (Flix, Spain) to compare trace metal (Hg, Pb, Cd, Se, As, Zn, Cu, Cr) bioaccumulation patterns among 16 food web components. Our results indicate that most organisms are suitable for Hg biomonitoring, whereas other metals are better monitored by only some of them. Biofilms and zebra mussel were the organisms with larger and more diverse biomonitoring capacity. However, we show that using groups of biomonitors increase the scope and strengths of the conclusions and specific goals can be better addressed. We conclude providing an overview of the strengths and weaknesses of the main organisms considered for biomonitoring trace metals in rivers and reservoirs.     

Occurrence and fate of alkylphenols and alkylphenol ethoxylates in sewage treatment plants and impact on receiving waters along the Ter River (Catalonia, NE Spain)

The partitioning of alkylphenols in the dissolved and particulate matter of influents, effluents, accumulation onto sludge and the impact of sewage treatment plant upon receiving waters was studied along the Ter River basin (Catalonia, NE Spain). A solid-phase extraction or pressurized liquid extraction followed by liquid chromatography-mass spectrometry was developed and permitted to determine target compounds with high efficiency in waters, particulate material and sludge. Nonylphenol mono- and diethoxylate, nonylphenol and octylphenol partitioned preferably upon particulate matter and sludge, whereas long chain NPE(3-15)O prevailed in the dissolved phase and was released by effluents. Within the treatment process, a net accumulation of alkylphenols in sludge was found, producing up to 148g/t/month. The removal efficiency of alkylphenols was of 37-90% and depended on the treatment. Assessment on the fate of these contaminants within STPs is discussed in terms of flow rates, biological oxygen demand and tons of sludge produced.     

Distribution of endocrine disruptors in the Llobregat River basin (Catalonia,NE Spain)

The Llobregat basin is a Mediterranean fluvial system with major agricultural, urban and industrial impacts. We combined chemical quantification by liquid chromatography–mass spectrometry with electrospray interface (LC-ESI-MS) and the recombinant yeast assay (RYA) assays to estimate the loads of endocrine disrupting compounds (EDCs) along the basin. Chemical analysis revealed maximum concentrations (at μg l⁻¹ level) of alkylphenols at the lower course of the Llobregat River, which correlated with high levels of estrogenic activity detected by RYA. Analysis by RYA and LC-ESI-MS of influent and effluent waters from four sewage treatment plants (STP) discharging into the basin showed the removal of 80–95% of EDCs by STP treatment. Chemical analysis data and RYA data showed a quasi-linear correlation, demonstrating the complementariness of both methods. Our data suggest that the concentrations of the analysed compounds were enough to explain the total estrogenicity of water and STP samples from the Llobregat basin.