خيارات البحث
النتائج 1651 - 1660 من 3,991
Persistent organic pollutants and inorganic elements in the Balearic shearwater Puffinus mauretanicus wintering off Portugal
2016
Costa, R.A. | Torres, J. | Vingada, J.V. | Eira, C.
This study presents the first data on trace element and organic pollutant concentrations in the Critically Endangered Balearic shearwater Puffinus mauretanicus collected in 2010 and 2011 in Portugal. Trace element levels were below the threshold levels for adverse effects on birds, despite the Hg concentrations in feathers (4.35μg·g–1ww). No significant differences were detected between individuals from 2010 and 2011 except for Se concentrations in liver, feathers and muscle (higher in 2010) and Ag in liver and muscle (higher in 2011). No significant differences were detected in total concentrations of organochlorine compounds in Balearic shearwaters between years, although PCB congeners -101 and -180 presented higher concentrations in individuals from 2010. The PCB congeners -138, -153 and -180, and 4.4-DDE were detected in all individuals. This study on toxic elements and organic pollutants in wintering Balearic shearwaters provides baseline data from which deviations can be detected in the future.
اظهر المزيد [+] اقل [-]Analysis of the TSP, PM10 concentrations and water-soluble ionic species in airborne samples over Sistan, Iran during the summer dusty period
2016
Dahmardeh Behrooz, Reza | Esmaili-Sari, Abbas | Bahramifar, Nader | Kaskaoutis, D.G.
The present study analyzes the total suspended particulates (TSP) and particulate matter less than 10 μm (PM10) concentrations along with the water-soluble ionic species (WSIS) in airborne dust samples collected in Zabol, located in the Sistan basin of southeast Iran. Rather extreme TSP and PM10 mean concentrations of 1867.0 μg m−3 and 433.4 μg m−3 are found, while the WSIS contribute only 8.9% and 19.3% to the TSP and PM10 mass, respectively indicating large fraction of water-insoluble crustal elements, carbonaceous aerosols and heavy metals that remained unexplored. Ca2+ is the most abundant ionic species contributing ∼25–26% to the total WSIS mass, followed by NH4+, K+, and SO42−. Important fractions of Cl− and Na+ (7–9% of the total WSIS mass) indicate the presence of saline dust storms over Sistan due to desiccation of the Hamoun lakes and uplift of evaporated minerals by the strong Levar (120-days) wind. High correlations between the WSIS suggest large possibility for formation of NaCl, (NH4)2SO4, MgSO4, K2SO4, CaSO4 and NH4NO3. The dusty days (visibility < 2 km) are associated with intense winds (11.7 ms−1 on average) and large increase (∼80–100%) in the concentrations of the crustal elements (e.g., Ca2+, Mg2+ and Cl−) compared to the normal days, while the TSP and PM10 concentrations reach to 4496 μgm−3 and 1010.6 μgm−3, respectively.
اظهر المزيد [+] اقل [-]Spatial and temporal distributions of polycyclic aromatic hydrocarbons in the Northern Arabian Gulf sediments
2016
Gevao, Bondi | Boyle, Edward A. | Carrasco, Gonzalo G. | Ghadban, Abdul Nabi | Zafar, Jamal | Bahloul, Majed
Surficial sediment samples were collected from 25 locations within Kuwait Bay and outside the Bay, in the Northwestern Arabian Gulf, to access recent polycyclic aromatic hydrocarbon pollution in Kuwait. Time trends in the depositional history of PAHs to this portion of the Arabian Gulf was reconstructed from the analysis of a dated sediment core. Intersite differences in concentration exist although these differences were not statistically significant (p=0.08). However, organic carbon normalized concentrations within Kuwait Bay were 4 times higher than the average concentrations outside the Bay and were shown to be statistically significant (p<0.001). The sedimentary record showed that ΣPAHs concentration fluctuated between 12 and 25ngg−1 before 1970. Concentrations then increased sharply to a maximum of 45ngg−1 around the late 1970s and early 1980s followed by an exponential decrease in concentration to pre-1970 “background” concentrations of between 12 and 25ngg−1.
اظهر المزيد [+] اقل [-]Concentrations of mercury and other trace elements in porbeagle shark Lamna nasus
2016
Nicolaus, E.E Manuel | Bendall, Victoria A. | Bolam, Thi P.C. | Maes, Thomas | Ellis, Jim
Concentrations of 11 trace elements in three tissues of porbeagle shark Lamna nasus (n=33) were determined. The maximum observed concentrations of Cd and Pb in muscle were 0.04 and 0.01mgkg−1, respectively, and all muscle samples were below European seafood limits for these metals. Hg concentrations in either the red or white muscle that exceeded European regulations for seafood were observed in one-third of specimens. Hg concentration, however, increased with length, and all fish >195cm had concentrations >1.0mgkg−1, with a maximum observed value of 2.0mgkg−1. Concentrations of Fe and Cu were, on average, 9.7 and 10 times higher in red muscle than in nearby white muscle, respectively. Mn, Zn, As and Se were also found in significantly higher concentrations in red muscle than in white muscle.
اظهر المزيد [+] اقل [-]The role of passive sampling in monitoring the environmental impacts of produced water discharges from the Norwegian oil and gas industry
2016
Hale, Sarah E. | Oen, Amy M.P. | Cornelissen, Gerard | Jonker, Michiel T.O. | Waarum, Ivar-Kristian | Eek, Espen
Stringent and periodic iteration of regulations related to the monitoring of chemical releases from the offshore oil and gas industry requires the use of ever changing, rapidly developing and technologically advancing techniques. Passive samplers play an important role in water column monitoring of produced water (PW) discharge to seawater under Norwegian regulation, where they are used to; i) measure aqueous concentrations of pollutants, ii) quantify the exposure of caged organisms and investigate PW dispersal, and iii) validate dispersal models. This article summarises current Norwegian water column monitoring practice and identifies research and methodological gaps for the use of passive samplers in monitoring. The main gaps are; i) the range of passive samplers used should be extended, ii) differences observed in absolute concentrations accumulated by passive samplers and organisms should be understood, and iii) the link between PW discharge concentrations and observed acute and sub-lethal ecotoxicological end points in organisms should be investigated.
اظهر المزيد [+] اقل [-]Neurological Disorders from Ambient (Urban) Air Pollution Emphasizing UFPM and PM2.5
2016
Bandyopadhyay, Amitava
Exposure to ambient (urban) air pollution consisting of fine particles is linked with the increased risk of respiratory as well as cardiovascular diseases and cancers. Recent studies have, however, suggested the adverse effects of PM₂.₅ and especially ultrafine particulate matter (UFPM or PM₀.₁: size <0.1 μm or 100 nm) in ambient air pollution in the brain and central nervous system (CNS). These particles can travel beyond the pulmonary systems to the CNS and, ultimately, reach the brain that may cause neurological diseases including Alzheimer’s disease, Parkinson’s disease, and other forms of dementia. The polychlorinated biphenyls (PCBs) can also be linked to neurological disorders identically. An attempt has been made in this article to make an assessment on the roles of UFPM and PM₂.₅ as well as PCBs on the neurological disorders from exposure to ambient air pollution. Finally, several recommendations are made for future scope of research followed by regulatory enforcement strategies to reduce the occurrence of neurological disorders from exposures of ambient air pollution to humans.
اظهر المزيد [+] اقل [-]Metal bioaccumulation and physiological condition of the Pacific oyster (Crassostrea gigas) reared in two shellfish basins and a marina in Normandy (northwest France)
2016
Seguin, A. | Caplat, C. | Serpentini, A. | Lebel, J. M. | Menet-nedelec, Florence | Costil, K.
A 5-month experiment combining a geochemical survey of metals with a bioaccumulation study in batches of Crassostrea gigas was conducted in two shellfish farming areas and a marina in Normandy (France). Various endpoints at different levels of biological organization were studied. ROCCH data showed differences in biota contamination between the two shellfish areas but the present study revealed only slight differences in metallic contamination and biomarkers. By contrast, significantly different values were recorded in the marina in comparison with the two other sites. Indeed, higher levels of Cd, Cu and Zn were measured in the oysters from the marina, and these oysters also showed a poorer physiological condition (e.g., condition index, histopathological alterations and neutral lipid content). For coastal monitoring, the multi-biomarker approach coupled with an assessment of metallic contamination in biota appeared to be suitable for discriminating spatial differences in environmental quality after only a few months of exposure.
اظهر المزيد [+] اقل [-]A semi-automated Raman micro-spectroscopy method for morphological and chemical characterizations of microplastic litter
2016
Frere, L. | Paul-pont, I. | Moreau, Julien | Soudant, P. | Lambert, C. | Huvet, Arnaud | Rinnert, Emmanuel
Every step of microplastic analysis (collection, extraction and characterization) is time-consuming, representing an obstacle to the implementation of large scale monitoring. This study proposes a semi-automated Raman micro-spectroscopy method coupled to static image analysis that allows the screening of a large quantity of microplastic in a time-effective way with minimal machine operator intervention. The method was validated using 103 particles collected at the sea surface spiked with 7 standard plastics: morphological and chemical characterization of particles was performed in < 3 h. The method was then applied to a larger environmental sample (n = 962 particles). The identification rate was 75% and significantly decreased as a function of particle size. Microplastics represented 71% of the identified particles and significant size differences were observed: polystyrene was mainly found in the 2–5 mm range (59%), polyethylene in the 1–2 mm range (40%) and polypropylene in the 0.335–1 mm range (42%).
اظهر المزيد [+] اقل [-]Heterogeneity of soil pollution
2016
Cattan P. | Woignier T. | Clostre F. | Lesueur Jannoyer M.
Crisis management of chronic pollution by chlordecone: conclusions
2016
Cattan P. | Clostre F. | Woignier T. | Lesueur Jannoyer M.