Bioaccumulation and trophic transfer of metals, As and Se through a freshwater food web affected by antrophic pollution in Córdoba, Argentina.

The concentration of metals (Al, Cr, Mn, Fe, Ni, Cu, Zn, Ag, Cd, Hg, Pb, U), As and Se in different ecosystem components (water, sediment, plankton, shrimp, and fish muscle) has been determined in a eutrophic reservoir in the Province of Córdoba (Argentina). Los Molinos Lake (LML) was sampled during the dry (DS) and wet seasons (WS) in order to examine the bioaccumulation and transfer of these inorganic elements through the food web. Stable nitrogen isotope (δ15N) was used to investigate trophic interactions. According to this, samples were divided into three categories: plankton, shrimp (Palaemonetes argentinus) and fish (Silverside, Odontesthes bonariensis). The bioaccumulation factor (BAF) was calculated for the organisms, and it was determined that the elements analyzed undergo bioaccumulation, especially in organisms such as plankton. The invertebrates were characterized by the highest BAF for Cu and Zn in both seasons, As (DS), and Cd and Hg (WS). The fish muscle was characterized by the highest BAF for Se (WS), Ag and Hg (DS). On the other hand, a significant decrease in Al, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Cd and U concentrations through the analyzed trophic web during both seasons was observed. Moreover, a significant increase in Hg levels was observed with increasing trophic levels in the DS, indicating its biomagnification. Despite the increasing impact of metals, As and Se pollution in the studied area due to urban growth and agricultural and livestock activities, no previous study has focused on the behavior and relationships of these pollutants with the biotic and abiotic components of this aquatic reservoir. We expect that these findings may be used for providing directions or guidance for future monitoring and environmental protection policies.

Assessment of exposure to metals, As and Se in water and sediment of a freshwater reservoir and their bioaccumulation in fish species of different feeding and habitat preferences.

The concentrations of metals (Ag, Al, Ba, B, Be, Bi, Cd, Co, Cr, Cu, Fe, Ga, Hg, Li, Mn, Mo, Ni, Pb, Rb, Sr, Tl, U, V, Zn), As and Se were analyzed in water and sediments from three sites of Río Tercero Reservoir (Córdoba, Argentina) during the wet and the dry season. The dynamics of metals in six fish species (Hoplias malabaricus, Oligosarcus jenynsii, Rhamdia quelen, Bryconamericus iheringii, Astyanax fasciatus and Odontesthes bonariensis) from the reservoir were investigated to discover the possible differential influence of habitat and diet on metal accumulation in the fish. In the abiotic matrix, the highest heavy metal concentrations were observed in sediment. The concentrations of Al, Cu and Pb in water exceeded the limits considered as hazardous for aquatic life. Potential ecological risk analysis of metal concentrations in sediment indicated a low ecological risk in Río Tercero Reservoir in all sampling periods. The enrichment factor indicated that Cu, Pb, Zn and Hg come from anthropogenic sources. Among five different organs, the highest metal levels were found in gills and intestine. Rhamdia quelen and Oligosarcus jenynsii were the species with the highest values of metal accumulation in the whole body. Our study showed that the accumulation pattern of these multi-elements in the different fish species did not respond to diet or habitat, but seemed to be related to the detoxification mechanisms and the metabolism of each organism.

Phytofiltration of As3+, As5+, and Hg by the aquatic macrophyte Potamogeton pusillus L, and its potential use in the treatment of wastewater.

The aim of this paper was to investigate the capacity of the aquatic macrophyte Potamogeton pusillus to remove As3+, As5+, and Hg from aqueous solutions. The plants were exposed to 0 mg.L-1, 0.1 mg.L-1, 0.5 mg.L-1, 1 mg.L-1, or 2 mg.L-1 of As3+, As5+, and Hg for 20 days. The results obtained for the individual removal of As3+, As5+, and Hg from water solutions, together with their accumulation in P. pusillus, indicate that this plant can be effectively used for the removal of Hg and of moderate concentrations of As3+ or As5+ (0.1 mg.L-1) from aquatic systems. Roots and leaves accumulated the highest amount of As when the plant was exposed to As5+, but when it was exposed to As3+, the root accumulated the highest amount of As, and the leaves, the highest amount of Hg. When compared to other aquatic plants species, the results showed that P. pusillus demonstrated a higher Hg accumulation (2465 ± 293 µg.g-1) when the transfer coefficient was 40,580 ± 3762 L.kg -1, showing the great potential of this macrophyte for phytoremediation of water contaminated with Hg. To the extent of our knowledge, this is the first report on bioaccumulation of As3+, As5+, and Hg by P. pusillus.

Oxidative stress response induced by atrazine in Palaemonetes argentinus: the protective effect of vitamin E.

The widespread contamination and persistence of the herbicide atrazine residues in the environment resulted in the exposure of non-target organisms. The present study was undertaken to investigate the effect of atrazine in the response of oxidative stress biomarkers in the freshwater shrimp Palaemonetes argentinus and the protective effect of vitamin-E against atrazine-induced toxicity. Therefore, two batches of P. argentinus were fed for 21 days with a commercial food enriched in proteins (D1) or with D2, composed of D1 enriched with vitamin-E (6.8 and 16.0mg% of vitamin-E, respectively). Subsequently, half of the individuals of each group were exposed to atrazine (0.4mgL(-1)) for 24h and the others remained as controls. Atrazine promoted oxidative stress response in P. argentinus fed with D1 as indicated by enhanced H2O2 content and induction of superoxide dismutase, glutathione-S-transferases and glutathione reductase. This antioxidant activity would prevent the increment of thiobarbituric acid reactive substances in the shrimp tissues. P. argentinus fed with D2 reversed the response of the biomarkers measured. However, the activation of antioxidants response had an energetic cost, which was revealed by a decrease in lipids storage in shrimps. These results show the modulatory effect of vit-E on oxidative stress and its potential use as an effective antioxidant to be applied in chemoprotection strategies during aquaculture.

Single and combined phytoextraction of lead and cadmium on submerged plants Potamogeton pusillus L.: removal, bioaccumulation pattern, and phytotoxicity.

Under the present investigation, the submerged plant Potamogeton pusillus has been tested for the removal of lead (Pb) and cadmium (Cd). P. pusillus removal efficiency and accumulation capacity were examined in separated Pb and Cd solutions, at 0.5, 1.0, and 2 mg L-1, and in solutions where both metals were present at the same concentration (0.5, 1.0, and 2 mg L-1), under laboratory conditions for 3, 7, and 10 days. Also, we examined the removal efficiency and accumulation capacity when a set of plants were exposed to 0.5 mg L-1 of Pb (or Cd) and increasing concentrations (0.5, 1, and 2 mg L-1) of Cd (or Pb) for 10 days. The effect of Cd and Pb was assessed by measuring changes in the chlorophylls, carotenoids, and malondialdehyde contents. Results showed that P. pusillus could accumulate Cd and Pb from individual solutions. Roots and leaves accumulated the highest amount of Cd and Pb followed by the stems. Some phytotoxic effects were observed, especially at individual Cd exposures, but these effects were not observed in the two-metal system. The removal and accumulation of Pb by P. pusillus were significantly enhanced in the presence of Cd under certain conditions, presenting a good alternative for the removal of these metals from polluted aquifers. To the extent of our knowledge, this is the first report on both enhanced phytoextraction of Pb in the presence of Cd and bioaccumulation of these heavy metals by P. pusillus.

Metal/metalloid bioconcentration dynamics in fish and the risk to human health due to water contamination with atmospheric particulate matter from a metallurgical industrial area.

Settleable atmospheric particulate matter (SeAPM) containing a mixture of metals, including metallic nanoparticles, has increased throughout the world, and caused environmental and biota contamination. The metal bioconcentration pattern in Nile tilapia (Oreochromis niloticus) was evaluated during a 30-day exposure to 1 g L-1 SeAPM and assessed the human health risk from consuming fish fillets (muscle) based on the estimated daily intake (EDI). SeAPM was collected surrounding an iron ore processing and steel industrial complex in Vitória city (Espírito Santo, Brazil) area. Water samples were collected daily for physicochemical analyses, and every 3 days for multi-elemental analyses. Metal bioconcentrations were determined in the viscera and fillet of fish every 3 days. The elements B, Al, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Rb, Sr, Ag, Cd, Pb, Hg, Ba, Bi, W, Ti, Zr, Y, La, Nb, and Ce were analyzed in SeAPM, water, and fish using inductively coupled plasma mass spectrometry. The metal concentration in SeAPM-contaminated water was higher than in control water. Most metals bioconcentrated preferentially in the fish viscera, except for the Hg and Rb, which bioconcentrated mostly in the fillet. The bioconcentration pattern was Fe > Al > Mn > Pb > V > La > Ce > Y > Ni > Se > As > W > Bi in the viscera; it was higher than the controls throughout the 30-day exposure. Ti, Zr, Nb, Rb, Cd, Hg, B, and Cr showed different bioconcentration patterns. The Zn, Cu, Sr, Sn, Ag, and Ta did not differ from controls. The differences in metal bioconcentration were attributed to diverse metal bioavailability in water and the dissimilar ways fish can cope with each metal, including inefficient excretion mechanisms. The EDI calculation indicated that the consumption of the studied fish is not safe for children, because the concentrations of As, La, Zr, and Hg exceed the World Health Organization's acceptable daily intake for these elements.

Integrating chemical and biological data by chemometrics to evaluate detoxification responses of a neotropical bivalve to metal and metalloid contamination.

Mangroves represent a challenge in monitoring studies due to their physical and chemical conditions under constant marine and anthropogenic influences. This study investigated metals/metalloids whole-body bioaccumulation (soft tissues) and the risk associated with their uptake, biochemical and morphological detoxification processes in gills and metals/metalloids immobilisation in shells of the neotropical sentinel oyster Crassostrea rhizophorae from two Brazilian estuarine sites. Biochemical and morphological responses indicated three main mechanisms: (1) catalase, superoxide dismutase and glutathione played important roles as the first defence against reactive oxygen species; (2) antioxidant capacity against peroxyl radicals, glutathione S-transferase, metallothionein prevent protein damage and (3) metals/metalloids sequestration into oyster shells as a mechanism of oyster detoxification. However, the estimated daily intake, target hazard quotient, and hazard index showed that the human consumption of oysters would not represent a human health risk. Among 14 analysed metals/metalloids, chemometrics indicate that Mn, As, Pb, Zn and Fe overload the antioxidant system leading to morphological alterations in gills. Overall, results indicated cellular vacuolization and increases in mucous cell density as defence mechanisms to prevent metals/metalloids accumulation and the reduction in gill cilia; these have long-term implications in respiration and feeding and, consequently, for growth and development. The integration of data from different sites and environmental conditions using chemometrics highlights the main biological patterns of detoxification from a neotropical estuarine bivalve, indicating the way in which species can cope with metals/metalloids contamination and its ecological consequences.

Uptake and accumulation of Cr in edible parts of Eruca sativa from irrigation water. Effects on polyphenol profile and antioxidant capacity.

Metals in the environment have been an increasing research topic over the past decade, since they can be found in both natural and drinking water, including irrigation of crops and edible plants with contaminated water. The aim of this study was to investigate the uptake of Cr by arugula (Eruca sativa) in a greenhouse experiment, simulating the open field irrigation conditions. We also evaluate the toxic effects of Cr on oxidative stress by measuring the antioxidant capacity and polyphenol profile in the plant. The study examines the irrigation of arugula, during 15 and 21 days, with four Cr (VI) concentrations, ranging from 0 (control) to 250 µg. L-1. Arugula plants were able to accumulate Cr when irrigated during 15 and 21 days in all the Cr concentrations evaluated. The estimated daily intake (EDI) shows that the amount of Cr accumulated by arugula plants does not represent a threat to human health. Application of Cr levels induced some changes in content, profile and capacity of antioxidants depending on Cr concentration and time of exposure. Taking into account that E. sativa is consumed due to its polyphenol-related health benefits, the allowable Cr limits in irrigation water should be reviewed, in order to maximize health benefits associated with its consumption, and also to improve vegetable quality. Arugula is a valuable and nutritious food, that should not be excluded from a balanced diet. Chromium concentration in irrigation water as well as the speciation forms present in vegetables should be controlled.

Different antibiotic profiles in wild and farmed Chilean salmonids. Which is the main source for antibiotic in fish?

Fish from both aquaculture and wild capture are exposed to veterinary and medicinal antibiotics (ABs). This study explored the occurrence and probable source of 46 antibiotic residues in muscle of farmed salmon and wild trout from Chile. Results showed that at least one AB was detected in all studied samples. Diverse patterns were observed between farmed and wild specimens, with higher ABs concentrations in wild fish. Considering antimicrobial resistance, detected ABs corresponded to the categories B (Restrict), C (Caution) and D (Prudence) established by Antimicrobial Advice Ad Hoc Expert Group (European Medicines Agency). Multivariate statistic was used to verify differences between farmed and wild populations, looking for the probable source of ABs as well. Principal components analysis (PCA) revealed that ciprofloxacin, moxifloxacin, enrofloxacin, amoxicillin, penicillin G, oxolinic acid, sulfamethoxazole, trimethoprim and clarithromycin were associated with wild samples, collected during the cold season. Conversely, norfloxacin, sulfaquinoxaline, sulfadimethoxine, nitrofurantoin, nalidixic acid, penicillin V, doxycycline, flumequine, oxacillin, pipemidic acid and sulfamethizole were associated with wild samples collected during the warm season. All farmed salmon samples were associated with ofloxacin, tetracycline, cephalexin, erythromycin, azithromycin, roxithromycin, sulfabenzamide, sulfamethazine, sulfapyridine, sulfisomidin, and sulfaguanidine. In addition, linear discriminant analysis showed that the AB profile in wild fish differ from farmed ones. Most samples showed ABs levels below the EU regulatory limit for edible fish, except for sulfaquinoxaline in one sample. Additionally, nitrofurantoin (banned in EU) was detected in one aquaculture sample. The differences observed between farmed and wild fish raise questions on the probable source of ABs, either aquaculture or urban anthropic activities. Further research is necessary for linking the ABs profile in wild fish with the anthropic source. However, to our knowledge, this is the first report showing differences in the ABs profile between wild and aquaculture salmonids, which could have both environmental and health consequences.

Seasonal variations on trace element bioaccumulation and trophic transfer along a freshwater food chain in Argentina.

Río Tercero Reservoir (RTR) is the largest artificial reservoir in the province of Córdoba (Argentina). Water, sediment, plankton, shrimp (Palaemonetes argentinus), and fish (Odontesthes bonariensis) were collected during the wet season (WS) and dry season (DS) from this reservoir. Concentrations of Ag, Al, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, P, Pb, Se, U, and Zn were determined to investigate their respective bioaccumulation pattern and trophic transfer in the food chain. Results showed that their concentrations in water were rather low except Pb, which exceed the limits considered as hazardous for aquatic life. The enrichment factor (EF) in sediments showed that most of the element were derived from anthropogenic sources. Furthermore, the bioaccumulation factor (BAF) determined that the elements undergo bioaccumulation, especially in organisms such as plankton. The invertebrates were characterized by the highest BAF for Cu, P, and Zn in both seasons; Ag, As, and Hg during WS; and Se during DS. Fish muscle registered the highest BAF for Hg (DS) and Se (WS). A significant decrease in Al, As, Cd, Cr, Cu (DS) Fe, Mn, Ni, Pb, Se, U, and Zn (DS) concentrations through the trophic chain was observed, indicating biodilution. Some notable exceptions were found as Cu (WS), Hg (DS), and P (both season) that showed biomagnification. Further studies are needed to establish differential behavior with different species and pollutant, particularly when the potential transfer is to edible organisms.

Multiantibiotic residues in commercial fish from Argentina. The presence of mixtures of antibiotics in edible fish, a challenge to health risk assessment.

The occurrence of 46 antibiotics (amphenicols, cephalosporins, dihydrofolate reductase inhibitors, fluroquinolones, macrolides, nitrofurans, penicillins, quinolones, sulfamides and tetracyclines) in Argentinean market fish were investigated by UPLC-MS/MS. Veterinary and human antimicrobials enrofloxacin, clarithromycin, roxithromycin, doxycycline and oxytetracycline were detected in 100% of the samples, being to our knowledge the first report of clarithromycin in edible fish muscle. Maximum Residual Limits were exceeded for at least one antibiotic in 82% of pacú, 57% of shad, 57% of trout and 50% of salmon samples. Chloramphenicol, furazolidone and nitrofurantoin (banned compounds in food items) were detected in 41%, 22% and 4% of the samples, respectively. Based on the estimated daily intake calculation, samples do not pose a serious risk to public health. Further investigation on the chronic impact and risk calculation of the mixture of antibiotics on the aquatic environment and human health is urgently needed.

Multielemental + isotopic fingerprint enables linking soil, water, forage and milk composition, assessing the geographical origin of Argentinean milk.

The aim of this work was to verify the usefulness of multielemental and isotopic fingerprint to differentiate the origin of milk samples from different areas, linking milk fingerprint with those corresponding to soil, water, and forage. Samples from four production areas in Argentina were analysed: 26 elements, δ2H, δ13C, δ15N and δ18O. Milk provenance was assessed using 16 variables (Na, Mg, Al, V, Co, Ni, As, Se, Rb, Sr, Mo, Hg, δ2H, δ18O, δ13C and K/Rb). Generalized Procrustes Analysis (GPA) demonstrated the consensus between soil, water, forage and milk, in addition to differences between studied areas. Canonical Correlation Analysis (CCA) demonstrated significant correlations between the milk-drinking water, milk-forage, and milk-soil. So far, we report a feasible method to establish the milk provenance, assessing the follow up from environmental matrixes (soil + water) to dairy products through the food web (forage) by a combined chemical-isotopic fingerprint.

Development of a method for the elemental analysis of milk powders using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) and its potential use in geographic sourcing.

Milk has been reported as one of the most adulterated foodstuffs in the developed and developing world. One way to detect adulteration is to determine whether the country of origin on the label could be the actual country of origin. Such profiling may be accomplished through the use of elemental analysis techniques, however this is a preliminary study and this goal is not yet met. In this study, a laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) method was developed for the analysis of solid milk powder and compared to k0-instrumental neutron activation analysis (k0-INAA) for a reference milk material (IAEA-153) as well as several milk samples from different countries. The analytical figures of merit for both the LA-ICP-MS and the k0-INAA analysis are reported. Precision of ~ 10% RSD or better was achieved for most elements for both techniques and bias of ~ 10% was achieved for both techniques for most elements with LA-ICP-MS producing lower limits of detection (~ 1 mg/kg) for Sr. The comparison of LA-ICP-MS to k0-INAA showed overlap of the 95% confidence intervals for all comparison samples. A total of 68 authentic milk powder samples representing 5 different countries (Argentina, Russia, Singapore, Slovenia, and the United States) were analyzed to determine whether multivariate elemental differences between the countries were sufficiently larger than within country differences in order to visualize groupings by country. Principle component analysis (PCA) using Na, Mg, Ca, Rb, and Sr show different groups for the United States, Argentina, Singapore, and Slovenia samples of limited representation for each country. However the large number and geographic distribution of samples from Russia were not able to be distinguished from the samples from the United States and Slovenia.