Affiner votre recherche
Résultats 2001-2010 de 7,288
First study on the determination of baseline biomarkers in Mimachlamys varia for an intra-port environmental biomonitoring in French Atlantic coastline (La Rochelle) Texte intégral
2022
Barbarin, Marine | Muttin, Frédéric | Thomas, Hélène
The characterization of organic and inorganic environmental pollution in coastal ecosystems, such as port areas, is complex and difficult to carry out due to the effect of environmental variables, as well as anthropic activities. For this study, the objective was to define a statistical method, taking into account the confounding factors influence, to define reference values for biomarkers in the black scallop (Mimachlamys varia). Thus, for five biomarkers (SOD (Superoxyde Dismutase), GST (Glutathion-S Transferase), MDA (Malondialdehyde), AChE (Acetylcholinesterase) and LAC (Laccase)), reference data could be described for individuals placed on sites more or less strongly impacted by specific environmental contaminations in port areas for more than two years, which had never been done before. All these results enabled us to calibrate and validate our approach in terms of active biomonitoring for the evaluation of a good ecological status of the environment of a port located on the French Atlantic coast.
Afficher plus [+] Moins [-]Spatial variability of water quality and sedimentary organic matter during winter season in coastal aquaculture zone of Korea Texte intégral
2022
Kim, Chung-Sook | Kim, Seung Hee | Lee, Won-Chan | Lee, Dong-Hun
We investigated the composition, source, and reactivity of sedimentary organic matter (OM) present in aquaculture systems along the Korean coast. A multi-isotopic approach was applied to 216 surface sediments from five sections: western (W)-1, W-2, southern (S)-1, S-2, and eastern (E)-1 sections. The ¹⁵N-enriched total nitrogen signatures in the surface sediments of the W-1 section may indicate that a substantial fraction of sedimentary OM has anthropogenic origins exported through the Han River. Simultaneously, the deposition of allochthonous OM is predominant in the S sections (Jinhae and Masan Bays). The ³⁴S-depleted patterns at the S-2 section may indicate that sulfate reduction occurring at the sedimentary boundary contributes to active OM decomposition, depending on the increased sedimentation of the aquaculture-derived OM. Our results highlight that isotopic-based source tracking near aquaculture systems provide important information for identifying anthropogenic contamination in coastal marine sediments and for improving environmental management.
Afficher plus [+] Moins [-]Contrasting sewage, emerging and persistent organic pollutants in sediment cores from the River Thames estuary, London, England, UK Texte intégral
2022
Vane, Christopher H. | Kim, Alexander W. | Lopes dos Santos, Raquel A. | Moss-Hayes, Vicky
Sedimentary organic pollution in the urban reaches of the Thames estuary is changing from fossil fuel hydrocarbons to emerging synthetic chemicals. De-industrialisation of London was assessed in three cores from Chiswick (Ait/Eyot) mud island using pharmaceuticals, faecal sterols, hydrocarbons (TPH, PAH), Black Carbon (BC) and organotins (TBT). These ranked in the order; BC 7590-30219 mg/kg, mean 16,000 mg/kg > TPH 770–4301, mean 1316 mg/kg > Σ¹⁶PAH 6.93–107.64, mean 36.46 mg/kg > coprostanol 0.0091–0.42 mg/kg, mean of 0.146 mg/kg > pharmaceuticals 2.4–84.8 μg/kg, mean 25 μg/kg. Hydrocarbons co-varied down-profile revealing rise (1940s), peak (1950s -1960s) and fall (1980s) and an overall 3 to 25-fold decrease. In contrast, antibiotics, anti-inflammatory (ibuprofen, paracetamol) and hormone (17β-estradiol) increased 3 to 50-fold toward surface paralleling increasing use (1970s-2018). The anti-epileptics, carbamazepine and epoxcarbamazepine showed appreciable down-core mobility. Faecal sterols confirmed non-systematic incorporation of treated sewage. Comparison to UK sediment quality guidelines indicate exceedance of AL2 for PAH whereas TBT was below AL1.
Afficher plus [+] Moins [-]Temporal trend of polychlorinated biphenyls contamination in the northwestern Arabian Gulf – Evidence from sediment records Texte intégral
2022
Gevao, Bondi | Uddin, Saif | Behbehani, Montaha | Fowler, Scott W.
This study provides an insight into the polychlorinated biphenyls (PCBs) inventories in the sediments of the northwestern Arabian/Persian Gulf. PCBs can be used as chemical markers that correlate with historical events in the region, to estimate the sedimentation rates in the northern Gulf, and to determine the sources of pollutants in the study area. The concentrations of PCBs were generally patchy in sediments. At Station 1 the ΣPCB concentrations generally fluctuated between 0.100 and 0.400 ng g⁻¹ dw throughout the depositional history measured in a sediment core. There were four peaks in the ΣPCB profile corresponding to 1969, 1979, 1983 and 1991. Station 2 showed a prominent peak at depth of 25 cm. The concentrations of the ΣPCBs and ΣICE congeners at this depth were 28 and 12 ng g⁻¹ dw respectively. Concentrations then dropped dramatically thereafter by a factor of 4. The ΣPCB concentrations at Station 3 were very low compared to the concentrations measured at Stations 1 and 2. The PCB concentration in Core 4 which was taken from open waters was 2–3 orders of magnitude lower than those in the other coastal cores. However, a 1990–91 peak was omnipresent in these cores. There is no record of PCB production within the Gulf region, and PCB releases into the Kuwait marine environment are likely to originate from their use in products. These maxima in early-1990s can be correlated to inputs from war-related activities, including the reported destruction of PCB-containing transformers and military equipment during the occupation of Kuwait. None of the recent sediment core sections at the four stations had a ΣPCB concentration near the effects range-median (ERM) concentration of 180 ng g⁻¹, or permissible exposure limits (PEL) of 189 ng g⁻¹, or were above the effect range-low (ERL) values of 22.7 ng g⁻¹.
Afficher plus [+] Moins [-]Environmental friendly Polyacrylonitrile nanofiber mats encapsulated and coated with green algae mediated Titanium oxide nanoparticles for efficient oil spill adsorption Texte intégral
2022
Poddar, Mrinal | Lakshmi, G.B.V.S. | Sharma, Mahima | Chaudhary, Navneet | Nigam, Subhasha | Joshi, Monika | Solanki, Pratima R.
Oil spill causes extreme environmental damage, from aquatic life to seabirds, disrupting the entire ecosystem. Herein, we have synthesized high scale, economical and bio-compatible, green algae mediated Titanium oxide (TiO₂) nanoparticles and Polyacrylonitrile (PAN) nanofiber mats. We have studied the effect of encapsulation and coating of TiO₂ nanoparticles over nanofiber mats for highly efficient oil spill adsorption. TiO₂ encapsulated and coated PAN (TECP) nanofibers showed a maximum of 62.34 g g⁻¹ adsorption capacity of petroleum oil from the water surface. Moreover, the composite mats show maximum adsorption within 45 s for up to 5 repeated cycles. Further, it has been observed that the adsorption capacity has increased by increasing the weight of the composite nanofiber mats, which confirms its commercial applicability. Thus, this work provides rapid, large-scale, economical, bio-compatible, and highly effective adsorbents for oil spill cleaning and extraction over natural waterbodies.
Afficher plus [+] Moins [-]Invasive behaviour of the marine Rhodophyta Sphaerococcus coronopifolius Stackhouse, in a hypereutrophic Mediterranean lagoon Texte intégral
2022
Lenzi, M. | Leporatti Persiano, M. | Gennaro, P.
Between 2017 and 2022, sediment labile organic matter, physico-chemical and nutrient content of the water column, biomass and C, N, P, S content of Sphaerococcus coronopifolius, a Rhodophyta that produced vegetative blooms in an area of the Orbetello lagoon (Italy) not far from the effluents of two land-based fish-farms, were examined and compared with an area even further away from that source where the species was not found. In order to understand the reasons for an important mat development in only one specific area, microcosm experiments were also carried out. Results suggest the species developed in dense and extensive mats under high orthophosphate and nitrate nitrogen ion concentrations conditions, behaving as an opportunistic species.
Afficher plus [+] Moins [-]Seasonal and body size-dependent variability in the bioaccumulation of PAHs and their alkyl homologues in pearl oysters in the central Arabian Gulf Texte intégral
2022
Soliman, Yousria | Wade, Terry L. | Sericano, Jose L. | Al Ansari, Ibrahim
Seasonal and body size-dependent variability in the bioaccumulation of PAHs and their alkyl homologues in pearl oysters in the central Arabian Gulf Texte intégral
2022
Soliman, Yousria | Wade, Terry L. | Sericano, Jose L. | Al Ansari, Ibrahim
Spatiotemporal concentration patterns for 19 parents and their alkyl homologues were measured in Pinctada radiata from 7 locations in the central Arabian Gulf around Qatar in the winter, spring and summer (2014–2015). The concentrations of PAHs ranged from 20 to 2240 (262 ± 38.0 ng·g⁻¹ dw) with the highest occurrence in the Doha harbor (738.4 ± 197.3 ng·g⁻¹ dw) and the lowest in the west coast of Qatar (48.3 ± 5.8 ng·g⁻¹ dw). Residual PAHs in the oysters were about two times higher in winter than in spring and summer (P < 0.05). PAHs in oysters are dominated by 2 and 3 rings PAHs and their alkyls. Alkylated PAHs (APAHs) comprised >55 % of the ΣPAHs. Statistically significant differences in PAHs profiles among oysters were due in part to differences in lipid contents and shell biometrics. Principal component analysis (PCA) and diagnostic ratios for sources identifications suggested that PAHs accumulations in oysters were due to petrogenic and fuel combustion.
Afficher plus [+] Moins [-]Seasonal and body size-dependent variability in the bioaccumulation of PAHs and their alkyl homologues in pearl oysters in the central Arabian Gulf Texte intégral
2022
Soliman, Yousria | Wade, Terry L. | Sericano, Jose L. | Al Ansari, Ibrahim
Spatiotemporal concentration patterns for 19 parents and their alkyl homologues were measured in Pinctada radiata from 7 locations in the central Arabian Gulf around Qatar in the winter, spring and summer (2014–2015). The concentrations of PAHs ranged from 20 to 2240 (262 ± 38.0 ng·g−1 dw) with the highest occurrence in the Doha harbor (738.4 ± 197.3 ng·g−1 dw) and the lowest in the west coast of Qatar (48.3 ± 5.8 ng·g−1 dw). Residual PAHs in the oysters were about two times higher in winter than in spring and summer (P < 0.05). PAHs in oysters are dominated by 2 and 3 rings PAHs and their alkyls. Alkylated PAHs (APAHs) comprised >55 % of the ΣPAHs. Statistically significant differences in PAHs profiles among oysters were due in part to differences in lipid contents and shell biometrics. Principal component analysis (PCA) and diagnostic ratios for sources identifications suggested that PAHs accumulations in oysters were due to petrogenic and fuel combustion. | This work was made possible by NPRP grant 6-442-1-087 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made here are solely the responsibility of the authors. | Scopus
Afficher plus [+] Moins [-]Spatiotemporal variability of the Persian Gulf and Oman Sea marine heatwaves during 1982–2020 Texte intégral
2022
Beyraghdar Kashkooli, Omid | Karimian, Sahar | Modarres, Reza
For the first time, this study explored the dominant features of Marine HeatWaves (MHWs) in the Persian Gulf and Oman Sea (1982–2020). The spatial extent of MHWs has nearly doubled in the last 24 years. Since 1997, the average number of MHW days in the central parts of the Persian Gulf has increased about 19 times compared to the period 1982–1997. The average number of the detected MHW events has increased by about three times. Simultaneously with the increase in MHWs frequency trend, the trend in the average number of MHW days has also increased. Since 1997, the average number of MHW days in the study area has almost increased by 10 times. The mean duration of the detected MHWs ranged from 5 to10 days. On average, in a major part of the Persian Gulf, about 1–2 MHW events occur annually.
Afficher plus [+] Moins [-]Impacts of the COVID-19 pandemic restrictions on solid waste pollution in the worldwide iconic Copacabana Beach (Rio de Janeiro, Brazil) Texte intégral
2022
Neves, Raquel A.F. | Seixas, Júlia T.C. | Rodrigues, Nathália | Santos, Luciano N.
Total and partial restrictions to beach access during COVID-19 pandemic created an opportunity to evaluate its effect on coastal pollution. We aimed to determine the impact of access restrictions on solid waste pollution at Copacabana beach, Brazil. Solid waste amount was analyzed considering beach access restrictions: unrestricted, total closure, partial restriction, new normal. Relationships of atmospheric temperature and precipitation with access restrictions were assessed and confounding effects controlled for further analyses. Beach access restrictions significantly reduced solid waste pollution at Copacabana beach, beach closure reduced waste amount in 72 %. Partial restrictions and new normal periods have significantly reduced solid wastes amount on the beach in 60 % and 36.88 %, respectively. Qualitative data revealed that most of solid wastes were single-use plastics recently disposed at Copacabana beach, reflecting beachgoer's effects on waste left on the beach. A positive impact of COVID-19 pandemic restrictions was detected on solid waste pollution at Copacabana beach.
Afficher plus [+] Moins [-]Assessment of trace metal concentrations in Indian Ocean silky sharks Carcharhinus falciformis and their toxicological concerns Texte intégral
2022
Wang, Ming-Huang | Chen, Chiu-Wen | Chen, Chih-Feng | Tsai, Wen-Pei | Dong, Cheng-Di
This study assessed the concentrations of nine trace metals from juvenile C. falciformis caught from Indian Ocean. This study also discussed the metal pollution index (MPI) and bioconcentration factor (BCF) of each element, and their correlations. Further, the potential health risks of consuming shark muscles (THI) were evaluated. Results showed the mean concentrations of 9 elements as follows: Cu (0.36 ± 0.17), Zn (5.19 ± 16.6), Pb (0.12 ± 0.23), Cd (0.17 ± 0.21), Cr (0.57 ± 1.61), Ni (0.086 ± 0.51), As (1.36 ± 0.83), Co (0.000073 ± 0.0074), and V (0.0024 ± 0.0094) mg/kg ww. The BCF values of the elements were higher than 1, with Co and V being the lowest indicating their bioaccumulative behavior. Correlation analysis showed MPI to be highly correlated with Cu, indicating its greater contributions to the total pollution load. Principal components analysis explained 81.0% of the variability in biometric characteristics and metal concentrations. Health risk assessment for consuming shark muscle in Taiwanese male and female adults suggests potential chronic non-carcinogenic health hazards.
Afficher plus [+] Moins [-]