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Particle deposition in a peri-urban Mediterranean forest
2016
Urban and peri-urban forests provide a multitude of Ecosystem Services to the citizens. While the capacity of removing carbon dioxide and gaseous compounds from the atmosphere has been tested, their capacity to sequestrate particles (PM) has been poorly investigated. Mediterranean forest ecosystems are often located nearby or inside large urban areas. This is the case of the city of Rome, Italy, which hosts several urban parks and is surrounded by forested areas. In particular, the Presidential Estate of Castelporziano is a 6000 ha forested area located between the Tyrrhenian coast and the city (25 km downtown of Rome). Under the hypothesis that forests can ameliorate air quality thanks to particle deposition, we measured fluxes of PM1, 2.5 and 10 with fast optical sensors and eddy covariance technique. We found that PM1 is mainly deposited during the central hours of the day, while negligible fluxes were observed for PM 2.5 and 10. A Hybrid Single–Particle Lagrangian Integrated Trajectory model (HYSPLIT v4) simulated PM emission from traffic areas in the city of Rome and showed that a significant portion of PM is removed by vegetation in the days when the plume trajectory meets the urban forest.
显示更多 [+] 显示较少 [-]TBBPA exposure during a sensitive developmental window produces neurobehavioral changes in larval zebrafish
2016
Tetrabromobisphenol A (TBBPA), one of the most widely used brominated flame retardants (BFRs), is a ubiquitous contaminant in the environment and in the human body. This study demonstrated that zebrafish embryos exposed to TBBPA during a sensitive window of 8–48 h post-fertilization (hpf) displayed morphological malformations and mortality. Zebrafish exposed exclusively between 48 and 96 hpf were phenotypically normal. TBBPA was efficiently absorbed and accumulated in zebrafish embryos, but was eliminated quickly when the exposure solution was removed. Larval behavior assays conducted at 120 hpf indicated that exposure to 5 μM TBBPA from 8 to 48 hpf produced larvae with significantly lower average activity and speed of movement in the normal condition than in those exposed from 48 to 96 hpf. Specifically, 8–48 hpf-exposed larvae spent significantly less time in both activity bursts and gross movements compared to control or 48–96 hpf exposed larvae. Consistent with the motor deficits, TBBPA induced apoptotic cell death, delayed cranial motor neuron development, inhibited primary motor neuron development and loosed muscle fiber during the early developmental stages. To further explore TBBPA-induced developmental and neurobehavioral toxicity, RNA-Seq analysis was used to identify early transcriptional changes following TBBPA exposure. In total, 1969 transcripts were significantly differentially expressed (P < 0.05, FDR < 0.05, 1.5-FC) upon TBBPA exposure. Functional and pathway analysis of the TBBPA transcriptional profile identified biological processes involved in nerve development, muscle filament sliding and contraction, and extracellular matrix disassembly and organization changed significantly. In addition, TBBPA also led to an elevation in the expression of genes encoding uridine diphosphate glucuronyl transferases (ugt), which could affect thyroxine (T4) metabolism and subsequently lead to neurobehavioral changes. In summary, TBBPA exposure during a narrow, sensitive developmental window perturbs various molecular pathways and results in neurobehavioral deficits in zebrafish.
显示更多 [+] 显示较少 [-]Persistent organic pollutants in blood samples of Southern Giant Petrels (Macronectes giganteus) from the South Shetland Islands, Antarctica
2016
Seabirds play an important role as top consumers in the food web and can be used as biomonitors of exposure to pollutants. Contamination studies involving non-destructive sampling methods are of considerable importance, allowing better evaluation of the levels of pollutants and their toxic effects. In the present study, organohalogen contaminants were analyzed in 113 blood samples from Southern Giant Petrel (Macronectes giganteus) adults and chicks collected in the austral summer of 2011/2012 and 2012/2013 from colonies on Elephant and Livingston Islands, South Shetland, Antarctica. Polychlorinated biphenyls (PCBs), hexachlorobenzene (HCB), pentachlorobenzene (PeCB), mirex, dichlorodiphenyltrichloroetane and derivatives (DDTs) and chlordanes were detected in all birds, whereas polybrominated diphenyl ethers (PBDEs) were not detected in any blood samples. No significant differences were found in organochlorine levels between sampling events. Adults exhibited significantly higher levels than chicks, except for PeCB. PCBs, HCB, mirex and DDTs were statistically similar in males and females from Elephant Island. Females on Livingston Island exhibited higher HCB values than males, but no sex differences were found regarding other organochlorines. The similarity in organochlorine levels between sexes in birds with very marked sexual segregation in feeding habits during the breeding season may indicate that significant amounts of contaminants are acquired during migration to lower latitudes, when the diets of males and females are similar. Birds sampled on Livingston Island exhibited significantly lower levels of PCBs, HCB, DDTs, mirex and chlordanes in comparison to those on Elephant Island, which could be the result of distinct foraging patterns between the two colonies. Organochlorine levels were similar between years in birds captured in two consecutive breeding seasons. Blood samples from Southern Giant Petrels adults and chicks proved to be useful for the comparison of intraspecific contamination levels and appear to be adequate for the long-term assessment of organohalogen contaminants in antarctic top predators.Organochlorine contaminants in blood samples of Southern Giant Petrels reflected intra-specific differences and suggested distinct foraging patterns between colonies.
显示更多 [+] 显示较少 [-]Exposure to widespread environmental endocrine disrupting chemicals and human sperm sex ratio
2016
Jurewicz, Joanna | Radwan, Michał | Sobala, Wojciech | Radwan, Paweł | Jakubowski, Lucjusz | Wielgomas, Bartosz | Ligocka, Danuta | Brzeźnicki, Sławomir | Hanke, Wojciech
In recent years, a trend toward a declining proportion of male births has been noted in several, but not all, industrialized countries. The underlying reason for the drop in the sex ratio is unclear, but one theory states that widespread environmental endocrine disrupting chemicals affecting the male reproductive system in a negative manner could be part of the explanation. The present study was designed to investigate whether the urinary phthalate, pyrethroids and polycyclic aromatic hydrocarbons metabolites concentrations were associated with sperm Y:X ratio.The study population consisted of 194 men aged under 45 years of age who attended infertility clinic in Lodz, Poland for diagnostic purposes with normal semen concentration of 20–300 mln/ml or with slight oligozoospermia (semen concentration of 15–20 mln/ml) (WHO, 1999). The Y:X ratio was assessed by fluorescent in situ hybridization. Urinary concentrations of 1-hydroxypyrene were measured by high performance liquid chromatography, phthalate metabolites were analyzed using a procedure based on the LC-MS/MS methods and metabolites of synthetic pyrethroids were assessed by gas chromatography ion-tap mass spectrometry method.After adjustment for potential confounders (past diseases, age, abstinence, smoking, alcohol consumption, sperm concentration, motility, morphology) 5OH MEHP, CDCCA to TDCCA and 1-OHP was negatively related to Y:X sperm chromosome ratio (p = 0.033, p < 0.001, p = 0.047 respectively).As this is the first study to elucidate the association between the level of metabolites of widespread environmental endocrine disrupting chemicals (phthalates, synthetic pyrethroids, polycyclic aromatic hydrocarbons) on sex chromosome ratio in sperm therefore, these findings require further replication in other populations.
显示更多 [+] 显示较少 [-]Impact of bisphenol A (BPA) on early embryo development in the marine mussel Mytilus galloprovincialis: Effects on gene transcription
2016
Balbi, Teresa | Franzellitti, Silvia | Fabbri, Rita | Montagna, Michele | Fabbri, Elena | Canesi, Laura
Bisphenol A (BPA), a monomer used in plastic manufacturing, is weakly estrogenic and a potential endocrine disruptor in mammals. Although it degrades quickly, it is pseudo-persistent in the environment because of continual inputs, with reported concentrations in aquatic environments between 0.0005 and 12 μg/L. BPA represents a potential concern for aquatic ecosystems, as shown by its reproductive and developmental effects in aquatic vertebrates.In invertebrates, endocrine-related effects of BPA were observed in different species and experimental conditions, with often conflicting results, indicating that the sensitivity to this compound can vary considerably among related taxa. In the marine mussel Mytilus galloprovincialis BPA was recently shown to affect early development at environmental concentrations. In this work, the possible effects of BPA on mussel embryos were investigated at the molecular level by evaluating transcription of 13 genes, selected on the basis of their biological functions in adult mussels. Gene expression was first evaluated in trocophorae and D-veligers (24 and 48 h post fertilization) grown in physiological conditions, in comparison with unfertilized eggs. Basal expressions showed a general up-regulation during development, with distinct transcript levels in trocophorae and D-veligers. Exposure of fertilized eggs to BPA (10 μg/L) induced a general upregulation at 24 h pf, followed by down regulation at 48 h pf. Mytilus Estrogen Receptors, serotonin receptor and genes involved in biomineralization (Carbonic Anydrase and Extrapallial Protein) were the most affected by BPA exposure. At 48 h pf, changes in gene expression were associated with irregularities in shell formation, as shown by scanning electron microscopy (SEM), indicating that the formation of the first shelled embryo, a key step in mussel development, represents a sensitive target for BPA. Similar results were obtained with the natural estrogen 17β-estradiol. The results demonstrate that BPA and E2 can affect Mytilus early development through dysregulation of gene transcription.
显示更多 [+] 显示较少 [-]Initial hazard screening for genotoxicity of photo-transformation products of ciprofloxacin by applying a combination of experimental and in-silico testing
2016
Toolaram, Anju Priya | Haddad, Tarek | Leder, Christoph | Kümmerer, Klaus
Ciprofloxacin (CIP) is a broad-spectrum antibiotic found within μg/L concentration range in the aquatic environment. It is a known contributor of umuC induction in hospital wastewater samples. CIP can undergo photolysis to result in many transformation products (TPs) of mostly unknown toxicity. The aims of this study were to determine the genotoxicity of the UV mixtures and to understand the possible genotoxic role of the stable TPs. As such, CIP and its UV-irradiated mixtures were investigated in a battery of genotoxicity and cytotoxicity in vitro assays. The combination index (CI) analysis of residual CIP in the irradiated mixtures was performed for the umu assay. Further, Quantitative Structure–Activity Relationships (QSARs) predicted selected genotoxicity endpoints of the identified TPs. CIP achieved primary elimination after 128 min of irradiation but was not completely mineralized. Nine photo-TPs were identified. The irradiated mixtures were neither mutagenic in the Ames test nor genotoxic in the in vitro micronucleus (MN) test. Like CIP, the irradiated mixtures were umuC inducing. The CI analysis revealed that the irradiated mixtures and the corresponding CIP concentration in the mixtures shared similar umuC potentials. QSAR predictions suggested that the TPs may be capable of inducing chromosome aberration, MN in vivo, bacterial mutation and mammalian mutation. However, the experimental testing for a few genotoxic endpoints did not show significant genotoxic activity for the TPs present as a component of the whole mixture analysis and therefore, further genotoxic endpoints may need to be investigated to fully confirm this.
显示更多 [+] 显示较少 [-]Environmental fate and effect assessment of thioridazine and its transformation products formed by photodegradation
2016
Wilde, Marcelo L. | Menz, Jakob | Trautwein, Christoph | Leder, Christoph | Kümmerer, Klaus
An experimental and in silico quantitative structure-activity relationship (QSAR) approach was applied to assess the environmental fate and effects of the antipsychotic drug Thioridazine (THI). The sunlight-driven attenuation of THI was simulated using a Xenon arc lamp. The photodegradation reached the complete primary elimination, whereas 97% of primary elimination and 11% of mineralization was achieved after 256 min of irradiation for the initial concentrations of 500 μg L−1 and 50 mg L−1, respectively. A non-target approach for the identification and monitoring of transformation products (TPs) was adopted. The structure of the TPs was further elucidated using liquid chromatography–high resolution mass spectrometry (LC–HRMS). The proposed photodegradation pathway included sulfoxidation, hydroxylation, dehydroxylation, and S- and N-dealkylation, taking into account direct and indirect photolysis through a self-sensitizing process in the higher concentration studied. The biodegradability of THI and photolytic samples of THI was tested according to OECD 301D and 301F, showing that THI and the mixture of TPs were not readily biodegradable. Furthermore, THI was shown to be highly toxic to environmental bacteria using a modified luminescent bacteria test with Vibrio fischeri. This bacteriotoxic activity of THI was significantly reduced by phototransformation and individual concentration-response analysis confirmed a lowered bacterial toxicity for the sulfoxidation products Thioridazine-2-sulfoxide and Thioridazine-5-sulfoxide. Additionally, the applied QSAR models predicted statistical and rule-based positive alerts of mutagenic activities for carbazole derivative TPs (TP 355 and TP 339) formed through sulfoxide elimination, which would require further confirmatory in vitro validation tests.
显示更多 [+] 显示较少 [-]Oxidative stress in duckweed (Lemna minor L.) induced by glyphosate: Is the mitochondrial electron transport chain a target of this herbicide?
2016
Gomes, Marcelo Pedrosa | Juneau, Philippe
We investigated the physiological responses of Lemna minor plants exposed to glyphosate. The deleterious effects of this herbicide on photosynthesis, respiration, and pigment concentrations were related to glyphosate-induced oxidative stress through hydrogen peroxide (H2O2) accumulation. By using photosynthetic and respiratory electron transport chain (ETC) inhibitors we located the primary site of reactive oxygen species (ROS) production in plants exposed to 500 mg glyphosate l−1. Inhibition of mitochondrial ETC Complex I by rotenone reduced H2O2 concentrations in glyphosate-treated plants. Complex III activity was very sensitive to glyphosate which appears to act much like antimycin A (an inhibitor of mitochondrial ETC Complex III) by shunting electrons from semiquinone to oxygen, with resulting ROS formation. Confocal evaluations for ROS localization showed that ROS are initially produced outside of the chloroplasts upon initial glyphosate exposure. Our results indicate that in addition to interfering with the shikimate pathway, glyphosate can induce oxidative stress in plants through H2O2 formation by targeting the mitochondrial ETC, which would explain its observed effects on non-target organisms.
显示更多 [+] 显示较少 [-]Evaluating the predictability of PM10 grades in Seoul, Korea using a neural network model based on synoptic patterns
2016
As of November 2014, the Korean Ministry of Environment (KME) has been forecasting the concentration of particulate matter with diameters ≤ 10 μm (PM10) classified into four grades: low (PM10 ≤ 30 μg m−3), moderate (30 < PM10 ≤ 80 μg m−3), high (80 < PM10 ≤ 150 μg m−3), and very high (PM10 > 150 μg m−3). The KME operational center generates PM10 forecasts using statistical and chemistry-transport models, but the overall performance and the hit rate for the four PM10 grades has not previously been evaluated. To provide a statistical reference for the current air quality forecasting system, we have developed a neural network model based on the synoptic patterns of several meteorological fields such as geopotential height, air temperature, relative humidity, and wind. Hindcast of the four PM10 grades in Seoul, Korea was performed for the cold seasons (October–March) of 2001–2014 when the high and very high PM10 grades are frequently observed. Because synoptic patterns of the meteorological fields are distinctive for each PM10 grade, these fields were adopted and quantified as predictors in the form of cosine similarities to train the neural network model. Using these predictors in conjunction with the PM10 concentration in Seoul from the day before prediction as an additional predictor, an overall hit rate of 69% was achieved; the hit rates for the low, moderate, high, and very high PM10 grades were 33%, 83%, 45%, and 33%, respectively. Our findings also suggest that the synoptic patterns of meteorological variables are reliable predictors for the identification of the favorable conditions for each PM10 grade, as well as for the transboundary transport of PM10 from China. This evaluation of PM10 predictability can be reliably used as a statistical reference and further, complement to the current air quality forecasting system.
显示更多 [+] 显示较少 [-]Levels, sources and risk assessment of PAHs in multi-phases from urbanized river network system in Shanghai
2016
Spatial-temporal distributions, sources identification and risk assessment of polycyclic aromatic hydrocarbons (PAHs) in overlying water and surface sediments in urban river networks of Shanghai were studied. Analytical results showed that there was a significant seasonal variation in concentrations of ∑16PAHs in water, suspended particulate matter (SPM) and sediment phases in this study area. The PAHs pollution in these multi-phases were in the medium level compared with other areas around the world, and the levels of PAHs contamination in SPM and sediment phases in hierarchical rivers showed TS (the third-order stream) > FS (the first-order stream) > SS (the second-order stream). Two manners of isomer ratios and principal component analysis (PCA) were used to identify PAHs origins, and suggested that combustion processes are dominant for PAHs sources. The ratios of PAHs origins by fossil fuels combustion, coke burning and crude oil in hierarchical rivers were determined with FS > SS > TS in SPM and sediment phases, and the ratio of PAHs origins by traffic emissions was analyzed with TS > SS > FS. PAHs in water samples have a certain impact on aqueous ecological system especially due to the fact that the ∑ceq values of nine PAHs were calculated from 0.715 to 15.831 μg/L in winter, which inferred serious ecological risk to some special aquatic organisms. The calculations of MERMQ in sediment samples showed that the MERMQ values ranged from 0.021 to 1.209 in winter and 0.019 to 0.643 in summer, which suggested high toxicity at six sampling sites in winter and only one location in summer due to high levels of PAHs. Furthermore, the toxicity degree of sediments were demonstrated with TS > FS > SS.
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