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Geochemical partitioning and pollution assessment of Ni and V as indicator of oil pollution in surface sediments from Shadegan wildlife refuge, Iran Texto completo
2016
Chaharlang, Behnam Heidari | Bakhtiari, Alireza Riyahi | Mohammadi, Jahangard | Farshchi, Parvin
The total concentrations and chemical partitioning of Ni, V and Fe have been assessed in surface sediments from 160 sites along the Shadegan wildlife refuge. The results showed that the average total level of Ni, V and Fe in surface sediments were 45.08±12.09, 25.25±20.8 and 25,979.01±6917.91μg/g dw, respectively. On the average, the chemical speciation of Ni, V and Fe in most stations were in the order of residual>oxidisable-organic>acid-reducible>exchangeable. In all fractions, the residual was accounted the highest proportion for the metals analyzed. Among the non-residual phases, the proportion of heavy metals in organic matter fraction was higher than other phases collected from all locations. The comparison between measured values in this study and some fresh water sediment quality guidelines indicated that the levels of nickel would be expected to sporadically cause harmful biological impacts on biota in the Shadegan wildlife refuge.
Mostrar más [+] Menos [-]Influence of petrochemical installations upon PAH concentrations at sites in Western Saudi Arabia Texto completo
2016
Harrison, Roy M. | Alam, Mohammed S. | Dang, Juan | Basahi, J. | Alghamdi, Mansour A. | Ismail, I.M. | Khoder, M. | Hassan, I.A.
Measurements of 16 polycyclic aromatic hydrocarbon (PAH) congeners (particles and vapour) have been made at three sites over a distance of 230 km on the Red Sea coast of Saudi Arabia. The data have been pooled with an earlier dataset from three sites in the city of Jeddah, with one urban site common to both studies. The concentrations and congener profiles are broadly similar for the two measurement campaigns at the common site. Coefficients of Divergence have been calculated and show more substantial differences between the sites within the city of Jeddah than are found between the sites to the north of the city which emphasises the strong concentration gradients within Jeddah in comparison to those found in the atmosphere of the coastal sites to the north of the city. A sub-set of data corresponding to days on which the air mass travelled from the northwest parallel with the Red Sea coast, hence linking the three sites, showed a progressive reduction in concentrations as the air mass travelled towards the southeast, which is attributed to emissions from a large source area to the northwest of the sampling sites and either atmospheric dilution or chemical reaction accounting for a progressive reduction in concentrations with advection of the air mass. The congener profile is very similar to that identified in earlier work relating to oil refinery emissions and is consistent with the major petrochemical installation at Yanbu contributing substantial emissions to the atmosphere which are advected to downwind sites.
Mostrar más [+] Menos [-]Transcription of a novel P450 gene varies with some factors (pollutant exposure, temperature, time, and body region) in a marine oligochaete (Thalassodrilides sp.) Texto completo
2016
Cytochrome P450 (CYP) enzymes play important roles in the metabolism of exogenous compounds such as polycyclic aromatic hydrocarbons (PAHs). A novel, full-length CYP gene (CYP4V30) was identified in the oligochaete Thalassodrilides sp. CYP4V30 mRNA expression was studied in worms exposed to PAH-polluted (Σ16PAHs; 37441ng/g dry weight) or unpolluted (Σ16PAHs; 19ng/g dry weight) sediment. CYP4V30 expression was much higher in worms exposed to contaminated sediments than in those exposed to unpolluted sediments at some temperatures (20 and 25°C) and exposure durations (11-fold increase at 20°C, 10-day exposure), but not at 15°C or other exposure durations (P<0.05). CYP4V30 mRNA expression was higher in the middle of the body than in the posterior (P<0.05). The variation in transcriptional response with exposure time, temperature, and body region indicates that these factors should be considered when monitoring marine sediment pollution.
Mostrar más [+] Menos [-]Baseline of polycyclic aromatic hydrocarbons in the surface sediment and sea cucumbers (Holothuria leucospilota and Stichopus hermanni) in the northern parts of Persian Gulf Texto completo
2016
Polycyclic aromatic hydrocarbons (PAHs) were determined in the surface sediments and in the sea cucumbers (Holothuria leucospilota and Stichopus hermanni) from around six Islands in the northern parts of Persian Gulf. The ranges of the average concentrations of PAHs in surface sediments, H. leucospilota and S. hermanni were 10.33–186.16ngg−1 dw, 12.49–505.44ngg−1 dw and 8.08–389.39ngg−1 dw, respectively. The spatial distribution of PAHs reveals that pollutant concentration is relatively higher at the western parts of Persian Gulf. International sedimentary quality guidelines (TEL-PEL) indicated a low probability of harmful effects to benthic organisms. PAH source identification showed that the PAHs in the sediments come from pyrogenic and mixed origin.
Mostrar más [+] Menos [-]Characteristics of water-soluble inorganic species in PM10 and PM2.5 at two coastal sites during spring in Korea Texto completo
2016
Park, Seung-Shik | Cho, Sŏng-yong | Jung, Chang-hoon | Lee, Kwon-Ho
PM10 and PM2.5 were collected during spring at East (“Gangneung”) and West (“Taean”) coastal sites of the Korean peninsula to investigate chemical characteristics and likely formation routes of their water-soluble inorganic species. The Gangneung site is inland, about 4.5–5.0 km from the East Sea; the Taean site is about 200 m from the coastline and about 400 km from eastern China. The total water-soluble ionic species contributions to PM10 and PM2.5 were respectively 28.8 and 37.4% at the Gangneung site and 46.8 and 53.1% at the Taean site. Concentrations of SO42−, NH4+, and NO3− in both PM10 and PM2.5 were found to be two times higher at the Taean site than at the Gangneung site. The potential source contribution function (PSCF) maps indicate that the enhancement of PM10 and its secondary aerosol species concentrations at two sites were primarily the result of atmospheric processing during long-range transport from the polluted regions of eastern China. Also upwind sources (“the capital region of Korea”) and local emissions influenced the concentration levels of secondary inorganic species at Gangneung.SO42− events, defined by PM10SO42− concentrations exceeding the average by one standard deviation, were identified at the two sites – six at Gangneung and four at Taean – to investigate possible mechanisms for the formation of SO42− and NO3−. High SO42− and high NO3− at the Gangneung site were strongly associated with either high RH (89–94%) and low wind speed or high O3 (62–103 ppb), suggesting that either gas-phase oxidation or aqueous phase oxidation played a critical role in the enhanced SO42− production. On the other hand, at the Taean site the association was with both high RH (76–92%) and high O3 (53–79 ppb), indicating that these conditions trigger aqueous-phase and gas-phase reactions to produce secondary SO42− and NO3− particles. Also long-range transport of air masses could be one possible factor for enhanced SO42− and NO3− concentrations during the events at the two coastal sites, as evidenced by PSCF maps.
Mostrar más [+] Menos [-]Distribution and risk assessment of suspected endocrine-disrupting pesticides in creek water of Mumbai, India Texto completo
2016
Singare, Pravin U.
The present study deals with the investigation of existing pollution levels and potential ecological risk assessment of endocrine-disrupting organochlorine and organophosphorous pesticide residues in the Vasai Creek water near Mumbai. The average concentration of α- and β-endosulfan (137.75ng·L−1) exceeds the chronic criteria level of α- and β-endosulfan (6.5ng·L−1) set by US EPA for freshwater aquatic organisms. The concentration levels of aldrin (75.31ng·L−1), dieldrin (71.19ng·L−1) and endrin (76.60ng·L−1) was found to exceed the respective criteria levels of <0.13, 65.1, and 61ng·L−1 as set by US EPA for protection of freshwater aquatic organisms. In addition, the level of chlorpyrifos (208.77ng·L−1) exceeds the recommended concentration value of <35ng·L−1 set by Ministry of Environment of British Colombia. The results of our study give an indication of probable ecotoxicological risk to the marine breeding organisms of creek.
Mostrar más [+] Menos [-]Oman's coral reefs: A unique ecosystem challenged by natural and man-related stresses and in need of conservation Texto completo
2016
Burt, J.A. | Coles, S. | van Lavieren, H. | Taylor, O. | Looker, E. | Samimi-Namin, K.
Oman contains diverse and abundant reef coral communities that extend along a coast that borders three environmentally distinct water bodies, with corals existing under unique and often stressful environmental conditions. In recent years Oman's reefs have undergone considerable change due to recurrent predatory starfish outbreaks, cyclone damage, harmful algal blooms, and other stressors. In this review we summarize current knowledge of the biology and status of corals in Oman, particularly in light of recent stressors and projected future threats, and examine current reef management practices. Oman's coral communities occur in marginal environmental conditions for reefs, and hence are quite vulnerable to anthropogenic effects. We recommend a focus on developing conservation-oriented coral research to guide proactive management and expansion of the number and size of designated protected areas in Oman, particularly those associated with critical coral habitat.
Mostrar más [+] Menos [-]Species-specific accumulation of methyl and total mercury in sharks from offshore and coastal waters of Korea Texto completo
2016
Kim, Sang-jo | Lee, Hyun Kyung | Badejo, Abimbola C. | Lee, Won-Chan | Moon, Hyo-Bang
Limited information is available on mercury (Hg) levels in various shark species consumed in Korea. The methyl-Hg (Me-Hg) and total Hg concentrations in all shark species ranged from 0.08 to 4.5 (mean: 1.2) mg/kg wet weight and from 0.1 to 7.0 (mean: 1.4) mg/kg wet weight, respectively. Inter-species differences in Hg accumulation were found among the species; however, Hg accumulation was homogenous between dorsal and pectoral fins within species. The highest Hg levels were found in aggressive carnivore shark species. Trophic position was important in determining Hg accumulation for aggressive carnivore sharks. Approximately 80% of shark species exceeded the safety limits for Me-Hg established by domestic and international authorities. The mean estimated daily intake of Me-Hg (1.3μg/kg body weight/day) for Korean populations consuming various sharks was higher than the guidelines proposed by international regulatory authorities, suggesting that excessive shark fin consumption may pose potential health risks for Koreans.
Mostrar más [+] Menos [-]Spatial and temporal distributions of polycyclic aromatic hydrocarbons in the Northern Arabian Gulf sediments Texto completo
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.
Mostrar más [+] Menos [-]Uptake of polycyclic aromatic hydrocarbons and their cellular effects in the mangrove Bruguiera gymnorrhiza Texto completo
2016
Naidoo, Gonasageran | Naidoo, Krishnaveni
The uptake of polycyclic aromatic hydrocarbons and their cellular effects were investigated in the mangrove Bruguiera gymnorrhiza. Seedlings were subjected to sediment oiling for three weeks. In the oiled treatment, the ƩPAHs was higher in roots (99%) than in leaves (1%). In roots, PAHs included phenanthrene (55%), acenaphthene (13%), fluorine (12%) and anthracene (8%). In leaves, PAHs possessed two to three rings and included acenaphthene (35%), naphthalene (33%), fluorine (18%) and phenanthrene (14%). In the roots, oil caused disorganization of cells in the root cap, meristem and conducting tissue. Oil contaminated cells were distorted and possessed large and irregularly shaped vacuoles. Ultrastructural changes included loss of cell contents and fragmentation of the nucleus and mitochondrion. In the leaves, oil caused dilation and distortion of chloroplasts and disintegration of grana and lamellae. Oil targets critical organelles such as nuclei, chloroplasts and mitochondria which are responsible for cell vitality and energy transformation.
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