1,721,105 research outputs found
Risk for human health of some POPs due to fish from Lake Iseo
No full textRisk evaluation for human health was carried out using PCB and PAH concentrations measured in seven fish species from Lake Iseo (Italy) and comparing the experimental data with legal levels and the two new approaches proposed by the US FDA and the US EPA to protect local populations with different food habits. We verified that none of the persistent organic compounds analyzed exceeded the legal limits set by the US FDA, since no specific limit has yet been proposed by the European Union. The two other approaches have pointed out that the acute and chronic effects do not represent any risk for human health, while a possible carcinogenic risk for the local population can arise when 4 and 8 monthly meals are consumed, based on PCB and PAH content in the edible part of fish, respectively
Analysis of the Dreissena polymorpha gill proteome following exposure to dioxin-like PCBs: Mechanism of action and the role of gender
No full textPCBs are a persistent environmental problem due to their high stability and lipophilicity. The non-ortho- and the mono-ortho-substituted PCBs (dioxin-like-PCBs) share a common and well-described toxicity mechanism in vertebrates, initially involving binding to cytosolic AhRs. Invertebrate AhRs, however, show a lack of dioxin binding, and little information is available regarding the mechanism of toxicity of dl-PCBs in invertebrates. In this study, a proteomic approach was applied to analyse the variations in the pattern of the gill proteome of the freshwater mussel Dreissena polymorpha. Mussels were exposed to a mixture of dl-PCBs, and to perform a more in-depth evaluation, we chose to investigate the role of gender in the proteome response by analysing male and female mussels separately. The results revealed significant modulation of the gill tissue proteome: glycolysis and Ca2+ homeostasis appear to be the main pathways targeted by dl-PCBs. In light of the differences between the male and female gill proteome profiles following exposure to dl-PCBs, further in-depth investigations of the role of gender in the protein expression profiles of a selected biological model are required
The PCB pollution of L. Iseo (N. Italy) and the role of biomagnification in the pelagic food web
No full textSeveral models of varying complexity have been used to predict pollutant concentrations in the higher levels of the food web from those in lower levels, but the role of the biomagnification process in aquatic food chains is still controversial. We used the fugacity-based approach to verify the transfer of PCBs through the pelagic food chain of Lake Iseo (N. Italy), sampling several zebra mussel specimens and some fish belonging of different trophic levels.
The zebra mussel seems to be a suitable starting species for modelling the bioaccumulation process through the trophic web, not only because its physiological characteristics and population size do not change much with time (as do algae and zooplankton) but also because it takes up toxicants exclusively from the water, as shown by the application of two predictive trophic models commonly used. The data provided by one of those models were in good agreement with our experimental data on fish in Lake Iseo, that show a not negligible uptake from food for the top predator species (pike and perch) with an increase of about three times in comparison with the PCB levels measured in the zebra mussel specimens
POPs in edible clams from different Italian and European markets and possible human health risk
No full textHuman intake of persistent organic pollutants (POPs) occurs primarily through diet and fish and other seafood represent the principal means of contamination. Despite this, few legal limits have been established to protect human health from the various chemicals that are alleged to be carcinogenic or endocrine disruptor compounds.
Several pools of edible clams (Tapes philippinarum and Venus gallina) bought in different Italian and European markets were examined in order to perform a risk assessment of some of these contaminants and also to identify possible health issues. POP concentrations in the soft tissues of mollusks varied considerably among source farming sites, particularly in the Venice Lagoon. Some POPs (DDTs, HCB and HCHs) showed very low concentrations and no risk for human health, in line with the limits established by European law. In contrast, PAHs could represent a potential hazard for human health and PCB levels in the most contaminated sites reached or even exceed the Minimal Risk Level as set by the ATSDR for human consumption, even if all the samples did not exceed the PCB limits in edible seafood as set by the FDA
Cyto-genotoxic effects induced by three brominated diphenyl ether congeners on the freshwater mussel Dreissena polymorpha
No full textPolybrominated diphenyl ethers (PBDEs) are a group of highly hydrophobic and persistent chemicals that has been used as flame retardants in several industrial applications. They have been detected in various environmental matrices worldwide and an increasing number of studies have recently been carried out to investigate their potential toxicity on ecosystem communities. Although a variety of biological damage has been documented in vertebrates, the effects on invertebrates are largely unknown. The objective of the present study was to determine the cyto-genotoxic effects induced by single exposure to three concentrations of 2,4,2',4'-tetra BDE (BDE 47), 2,2,4,4,6-penta BDE (BDE-100) and 2,2',4,4',5,6-hexa BDE (BDE-154) on the freshwater mussel Dreissena polymorpha by a multi-biomarker approach. We performed on bivalve hemocytes the Single Cell Gel Electrophoresis (SCGE) assay, the DNA Diffusion assay and the Micronucleus test (MN test) to assess genotoxicity, while the Neutral Red Retention Assay (NRRA) was used to evaluate cytotoxic effects. Results showed that BDE-47 did not produce any genetic damage at the tested concentrations (0.1 mu g/L, 0.5 mu g/L and 1 mu g/L), while BDE-100 and BDE-154 can be considered moderately genotoxic, since both primary and fixed DNA injuries were induced. The NRRA indicated a moderate increase in cellular stress in BDEs-treated bivalves. Thus, our data seems to suggest that investigated BDEs may pose a low risk to freshwater mussels at environmental concentrations
DDT is still a problem in developed countries: the heavy pollution of Lake Maggiore
No full textThe Zebra mussel (Dreissena polymorpha), one of the most widely used bioindicators of persistent organic pollutants, trace metals and radionuclides in several worldwide freshwater ecosystems, has been used to monitor DDT contamination trends in Lake Maggiore since 1996, caused by industrial effluents on a tributary of the River Toce, one of the major affluents of the lake. Dreissena specimens were collected at two sampling sites, one within the Baveno Bay, where the River Toce flows, and the other outside (Villa Taranto). Total DDT levels (3119.6 ng/g lipids at Baveno and 1351.2 ng/g lipids at Villa Taranto) in the soft tissues of the Zebra mussel decreased at both stations by about 30-50% in the first year after the closure of the chemical plant reaching an almost steady-state condition. The high concentrations measured in Zebra mussel specimens of Baveno Bay in 2000 (1947 ng/g lipids) and the percentage of pp'DDE in comparison with total DDT concentration, which showed a slight increase in the last years, clearly indicate that a contamination source is still present, deriving probably from the lacustrine sediments and the River Toce. Data show that the environmental risk is very high within the Baveno Bay and the recovery time should be longer than in the other parts of the lake, where DDT levels in Dreissena are presently two times higher than those measured in the other Italian subalpine lakes
Adverse effects induced by ecgonine methyl ester to the zebra mussel: A comparison with the benzoylecgonine
No full textCocaine and its metabolites are the prevalent psychotropic substances in aquatic environment. However, to date the knowledge on their adverse effects to non-target organisms is inadequate. The aims of this study were to investigate sub-lethal effects induced by the ecgonine methyl ester (EME) to the freshwater bivalve Dreissena polymorpha and to compare its toxicity to that by benzoylecgonine (BE), the other main cocaine metabolite. EME sub-lethal effects were investigated by 14 days in-vivo exposures and a multi-biomarker approach. Slight variations in biomarker responses were found at 0.15 μg/L treatment. 0.5 μg/L EME treatment induced destabilization of lysosome membranes, an overall inactivation of defense enzymes, increases in lipid peroxidation, protein carbonylation and DNA fragmentation, but no variations in fixed genetic damage. The use of a biomarker response index (BRI) showed that at 0.5 μg/L both cocaine metabolites had the same toxicity to zebra mussels specimens
Temporal trends of polycyclic aromatic hydrocarbons (PAHs) in Dreissena polymorpha specimens from Lake Maggiore (Northern Italy)
No full textThe Lake Maggiore (Northern Italy) has been recognized as an aquatic environment heavily contaminated by persistent organic pollutants, mainly organochlorine compounds, but to date limited information is available regarding another class of widespread and hazardous pollutants, such as the polycyclic aromatic hydrocarbons (PAHs). The aim of this study was to investigate seasonal and temporal trends of 18 PAHs accumulated in native Dreissena polymorpha specimens during a 5-year biomonitoring program, as well as to identify the possible PAH emission sources by using isomeric diagnostic ratios. Zebra mussels were sampled both in their pre- (May) and post-reproductive (September) stage over the 2008-2012 period in eight sampling stations covering the whole lake shoreline. PAH concentrations were measured through gas chromatography coupled to mass spectrometry. A notable PAH contamination following an increasing temporal trend was noticed in bivalves from all the sampling stations, with the benzo(alpha)anthracene as the predominant compound. An overall increase in PAH levels was found in the post-reproductive surveys, indicating a marked seasonality of this contamination probably due to the increase in touristic activity during spring-summer months
Oxidative and genetic responses induced by Δ-9-tetrahydrocannabinol (Δ-9-THC) to Dreissena polymorpha
No full textCannabis is the most used illicit substance worldwide and its main psychoactive compound, the Δ-9-tetrahydrocannabinol (Δ-9-THC), is detected in aquatic environments at measurable concentrations. Even though its occurrence is well documented, no information is available on its hazard to aquatic organisms. The aim of this study was to assess the adverse effects induced to zebra mussel (Dreissena polymorpha) specimens by 14 day exposures to environmentally relevant Δ-9-THC concentrations (0.05 μg/L and 0.5 μg/L) by means of the application of a biomarker suite. Catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione S-transferase (GST) activities, as well as the lipid peroxidation (LPO) and protein carbonyl content (PCC), were measured as oxidative stress indices. The single cell gel electrophoresis (SCGE) assay, the DNA diffusion assay and the micronucleus test (MN test) were applied to investigate DNA injuries, while the neutral red retention assay (NRRA) was used to assess Δ-9-THC cytotoxicity. The lowest treatment induced negligible adverse effects to bivalves, while 0.5 μg/L Δ-9-THC exposure caused remarkable alterations in D. polymorpha oxidative status, which lead to significant increase of lipid peroxidation, protein carbonylation and DNA damage
Environmental quality of the Po River delta
No full textThe Po River collects the discharges of the most populated and industrialized area of Northern Italy and enters the Adriatic Sea with a mean flow of 1470 m 3 s -1 spreading in nine branches along the final stretch and forming a delta originating about 50 km from the sea. According to the last systematic survey carried out in 1989-1990, the Po delta waters suffer a low-moderate pollution from heavy metals and organic micropollutants. However, the Po River carries a nutrient load high enough to cause a severe marine eutrophication problem south of its delta. Provisional models have shown that even a substantial reduction on civil and industrial waste water discharges coupled with an optimal use of fertilizers in agriculture would not be sufficient to solve the problem. The Po River represents an important source also, for heavy metals and marine sediments collected at the river mouth are more polluted than are those offshore, especially for Cu, Zn and Hg. On the basis of the European guidelines the delta sediments have a medium to high contamination as far as the concentration of Ni and DDT are concerned, while data on persistent organic compounds indicate a moderate ecological risk for the biota living in the delta. These same conclusions can be obtained using the "sediment quality benchmark" procedure proposed by the NOAA in the United States
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