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Gender-specific metabolic responses in gonad of mussel Perna viridis to triazophos Texte intégral
2017
Zhang, Linbao | Sun, Wei | Zhang, Zhe | Chen, Haigang | Jia, Xiaoping | Cai, Wengui
Triazophos, as a lipophilic organophosphate pesticide, displays higher bioaccumulation in the gonads of shellfish. To study the reproductive toxicity of triazophos, we applied metabolomics to characterize the gender-specific metabolic responses in mussel Perna viridis exposed to triazophos. Metabolites were differently altered by triazophos in ovaries of mussel at different concentrations and time intervals, while basically similar metabolic response patterns were observed in male mussels at the two tested concentrations after exposure for 24 and 48h. The significant changes of metabolites in ovaries of mussel exhibited the disturbances in energy metabolism and osmotic regulation, while in male samples triazophos only affected the energy metabolism. Moreover, glycine, sn-glycero-3-phosphocholine, ethanol, aspartate, etc. exhibited consistent variation tendency in both male and female individuals. While the changes of homarine, betaine, taurine, hypotaurine, malonate, β-alanine, succinate, and choline showed obviously gender-specific responses. Overall, this study confirmed the gender-specific responses in gonad of P. viridis to triazophos exposure.
Afficher plus [+] Moins [-]Evaluating real-world emissions of light-duty gasoline vehicles with deactivated three-way catalyst converters Texte intégral
2017
Zheng, Xuan | Wu, Ye | Zhang, Shaojun | He, Liqiang | Hao, Jiming
Three-way catalyst (TWC) converter is one of the most important after-treatment device for modern light-duty gasoline vehicles (LDGVs), which can efficiently control exhaust emissions of carbon monoxide (CO), total hydrocarbons (THC) and nitrogen oxides (NOX). Nevertheless, a considerable part of in-use taxis in Beijing would operate with TWC purposely removed, which have been indicated by vehicular on-board diagnostic (OBD) systems. In light of high vehicle-use intensity for taxis, we recruited three China 4 non-TWC taxis and three China 4 normal taxis in a comparative experimental test by using a portable emissions measurement system (PEMS). The results indicated that non-TWC taxis emitted significantly higher emissions of air pollutants than normal taxis with TWC functioning. For example, average emission factors of non-TWC vehicles were comparable to emission levels of China 1 LDGVs measured in previous studies. By contrast, emissions from normal China 4 taxis were all below China 4 emission limits. Furthermore, an operating mode binning method and a micro-trip approach have been employed to link vehicle emissions with driving conditions. For non-TWC taxis, we identified strong correlations of all pollutant categories between emission factors and average speed. However, such correlations for normal taxis were less strong, in particular for CO and THC emissions that were hardly sensitive to speed changes. This phenomenon indicates that the role of traffic conditions in affecting real-world emissions would become weaker when TWC can effectively mitigate emissions. This paper highlights the importance of in-use emission inspection to avoid any “high emitters” that have violated regulation enforcement.
Afficher plus [+] Moins [-]Accumulation of endocrine disrupting chemicals in the liver of Diplodus sargus sargus in Torre Guaceto Natural Reserve Texte intégral
2017
Rizzo, Daniela | Pennetta, Antonio | De Benedetto, Giuseppe E.
Studies on the quality of marine environments in Italy have traditionally favoured heavily impacted areas, such as harbours and industrial areas, while there are few investigations aimed at the evaluation of the presence of organic pollutants in the areas of marine reserve. The aim of this study was to determine endocrine-disrupting compounds (EDCs) in the liver of white seabreams (Diplodus sargus sargus) from the Natural Reserve of Torre Guaceto, Italy. Among EDCs, alkyl-phenols 2,6-DTBP, 2,4-DTBP, OP, and BPA were identified and quantified. The mean concentration of 2,6-DTBP, 2,4-DTBP, OP, and BPA were 2.2, 2.0, 1.2 and 3.6ng/g of liver, respectively, confirming the occurrence and transfer of these organic pollutants in the food web of marine organisms in marine reserves.
Afficher plus [+] Moins [-]Plastic in Cassin's Auklets (Ptychoramphus aleuticus) from the 2014 stranding on the Northeast Pacific Coast Texte intégral
2017
Floren, Hannah P. | Shugart, Gary W.
Oceanic plastic debris found in the digestive tracts of seabirds includes industrial plastic pellets and post-consumer user plastics. We examined whether the amount and type of plastic ingested by Cassin's Auklets (Ptychoramphus aleuticus) is changing by surveying the stomach contents of 171 Cassin's Auklets stranded along the Washington and Oregon coasts in 2014. We found that 41.5% of the birds contained plastic in their ventriculi, similar to values from the North Subarctic Pacific reported in the 1980s. Industrial pellets were found in 22.8% of our samples, and accounted for 28.1% of all the plastic pieces found. Industrial pellets tended to be larger than pieces of user plastic and accounted for 40.2% of total plastic weight. These industrial pellets were significantly smaller than those found in other species, suggesting either that Cassin's Auklets selected smaller plastic particles or that plastic was retained in ventriculi and worn down.
Afficher plus [+] Moins [-]Marine debris in five national parks in Alaska Texte intégral
2017
Polasek, L. | Bering, J. | Kim, H. | Neitlich, P. | Pister, B. | Terwilliger, M. | Nicolato, K. | Turner, C. | Jones, T.
Marine debris is a management issue with ecological and recreational impacts for agencies, especially on remote beaches not accessible by road. This project was implemented to remove and document marine debris from five coastal National Park Service units in Alaska. Approximately 80km of coastline were cleaned with over 10,000kg of debris collected. Marine debris was found at all 28 beaches surveyed. Hard plastics were found on every beach and foam was found at every beach except one. Rope/netting was the next most commonly found category, present at 23 beaches. Overall, plastic contributed to 60% of the total weight of debris. Rope/netting (14.6%) was a greater proportion of the weight from all beaches than foam (13.3%). Non-ferrous metal contributed the smallest amount of debris by weight (1.7%). The work forms a reference condition dataset of debris surveyed in the Western Arctic and the Gulf of Alaska within one season.
Afficher plus [+] Moins [-]Determination and assessment of phthalate esters content in sediments from Kaohsiung Harbor, Taiwan Texte intégral
2017
Chen, Chih-Feng | Chen, Chiu-Wen | Ju, Yun-Ru | Dong, Cheng-Di
Phthalate esters (PAEs) are known organic endocrine disruptors. The distribution of 10 PAEs in sediments of Kaohsiung Harbor of Taiwan was studied using organic solvents extraction and quantified by gas chromatography/mass spectrometry. The average concentration of total PAEs (ΣPAEs) in the sediment was 8713±11,454ng/g dw with di-(2-ethylhexyl) phthalate (DEHP) (3630ng/g-dw) and diisononyl phthalate (DiNP) (3497ng/g dw) being the major species, which constitutes of 41.7% and 40.1% of ΣPAEs. PAEs concentration was relatively high near the river mouths, especially in Love River mouth, and diminished toward the harbor. Based on the sediment quality guidelines developed from previous studies, several of the observed PAE levels exceeded the Maximum Contaminant Level, especially for DEHP and thus may cause adverse effect in aquatic organisms.
Afficher plus [+] Moins [-]Assessment of natural radioactivity and gamma-ray dose in monazite rich black Sand Beach of Penang Island, Malaysia Texte intégral
2017
Activity concentrations of primordial radionuclides in sand samples collected from the coastal beaches surrounding Penang Island have been measured using conventional γ-ray spectrometry, while in-situ γ-ray doses have been measured through use of a portable radiation survey meter. The mean activity concentrations for 226Ra, 232Th and 40K at different locations were found to be less than the world average values, while the Miami Bay values for 226Ra and 232Th were found to be greater, at 1023±47 and 2086±96Bqkg̶ 1 respectively. The main contributor to radionuclide enrichment in Miami Bay is the presence of monazite-rich black sands. The measured data were compared against literature values and also recommended limits set by the relevant international bodies. With the exception of Miami Bay, considered an elevated background radiation area that would benefit from regular monitoring, Penang island beach sands typically pose no significant radiological risk to the local populace and tourists visiting the leisure beaches.
Afficher plus [+] Moins [-]Organotins and new antifouling biocides in water and sediments from three Korean Special Management Sea Areas following ten years of tributyltin regulation: Contamination profiles and risk assessment Texte intégral
2017
A simultaneous monitoring study on organotins (butyltins and phenyltins) and most frequently used alternative antifouling biocides (Irgarol 1051, Diuron, Sea-Nine 211 and M1) in water and sediments (n=44) collected from three Special Management Sea Areas operated by Korean government. The lower concentration of butyltins (BTs) than that of new antifouling biocides (NEW) was found in water but the significant greater concentration of BTs than that of NEW was still found in sediments. The tributyltin (TBT) levels in water exceeded the chronic criterion to protect seawater aquatic life at several sites. Even ten years after the ban of the use of TBT-based antifouling paint, the concentrations of TBT, Diuron and Irgarol 1051 in sediments from shipyards exceeded global sediment quality guidelines and potentially poses adverse risks on marine organisms and extremely high concentration of TBT up to 2304ng/g was found for a sediment collected at a shipyard.
Afficher plus [+] Moins [-]Nitric-oxide generation induced by metals plays a role in their accumulation by Phallusia nigra hemocytes Texte intégral
2017
Ascidians are good monitors for assessing water quality, since they filter large volumes of water; however, little is known about how xenobiotics, including metals, can affect ascidian hemocytes. Metals can be either toxic or beneficial to health, inducing many different responses. The response mechanism depends on the class of metals to which organisms are exposed: essential, nonessential, and borderline. To analyze the influence of metals from different classes on the protective mechanisms of an ascidian, we investigated the production of nitric oxide (NO) after exposure to various concentrations of Mg, Mn and Pb over different time periods. We also determined the amounts of each metal in the hemocytes. Our results indicated that especially Pb could stimulate NO production. Although Pb induced the highest NO production, cell viability was not severely altered in all Pb concentrations and time periods. Ascidians might serve as biomonitor for Pb, since their vanadocytes accumulate Pb.
Afficher plus [+] Moins [-]Ubiquity of microplastics in coastal seafloor sediments Texte intégral
2017
Ling, S.D. | Sinclair, M. | Levi, C.J. | Reeves, S.E. | Edgar, G.J.
Microplastic pollutants occur in marine environments globally, however estimates of seafloor concentrations are rare. Here we apply a novel method to quantify size-graded (0.038–4.0mm diam.) concentrations of plastics in marine sediments from 42 coastal and estuarine sites spanning pollution gradients across south-eastern Australia. Acid digestion/density separation revealed 9552 individual microplastics from 2.84l of sediment across all samples; equating to a regional average of 3.4 microplastics·ml−1 sediment. Microplastics occurred as filaments (84% of total) and particle forms (16% of total). Positive correlations between microplastic filaments and wave exposure, and microplastic particles with finer sediments, indicate hydrological/sediment-matrix properties are important for deposition/retention. Contrary to expectations, positive relationships were not evident between microplastics and other pollutants (heavy metals/sewage), nor were negative relationships with neighbouring reef biota detected. Rather, microplastics were ubiquitous across sampling sites. Positive associations with some faunal-elements (i.e. invertebrate species richness) nevertheless suggest high potential for microplastic ingestion.
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