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1.
Environmental Science and Pollution Research - Offshore fish farms have been active inside the Monastir Bay, Hammemet Gulf for over 10 years, but their environmental impact is still...  相似文献   

2.
High rates of egg infertility and embryo death in a colony of South Polar Skuas breeding in the Antarctic were similar to those in polluted North Atlantic populations of the Great Skua. Such loss could not be linked to factors such as organochlorine pollutants, as levels of DDE and PCBs in the contents of skua eggs from the population were only a small fraction of those in polluted skua populations from the Northern Hemisphere. Average eggshell thickness for skuas nesting on Ross Island has shown no significant change since the introduction of DDT. Concentrations of DDE and PCBs in South Polar Skuas were 13 and 22 times higher, respectively, than those in the eggs of sympatric Adélie Penguins, and this probably reflects the greater exposure of skuas to pollution when they migrate north of the Antarctic Convergence in winter. Residues in liver tissue showed a similar trend, and a higher rate of mixed function oxidase induction in skua liver compared to that of penguins is consistent with the trends seen in pollutant levels. The same PCB congener predominated in both skua and penguin samples. Comparisons with historical residue data suggest that global levels of DDT residues are declining.  相似文献   

3.
Studies related to phytoremediation by conifers are still at their beginning. Thus, we investigated the ability of a hybrid larch (Larix x eurolepis) to accumulate cadmium (Cd). One-month-old clonal plantlets grown in vitro were exposed for 1 week to a high Cd concentration (1.5 mM). No significant effect was observed on root and shoot biomass, root length, and needle number as a result of Cd treatment. Leaf photosynthetic pigment content and total soluble protein concentration in roots and shoots remained unchanged compared to control plantlets. Taken together, these results suggested that hybrid larch tolerated Cd in our conditions. The high Cd concentration in shoots (200 μg Cd gram?1 dry weight) showed the good capacity of larch to translocate Cd and thus a potential use of this species for phytoremediation. Furthermore, under our conditions, phytochelatin biosynthesis pathway was slightly stimulated, suggesting that this pathway did not reach the threshold and/or another mechanism of Cd storage may be involved to explain larch tolerance to Cd.  相似文献   

4.
The understanding of the global environmental multiphase distribution of persistent organic pollutants (POPs) as a result of the physico-chemical properties of the respective compounds is well established. We have analysed the results of a vertical transport of POPs from upper water layers (0-200 m) to the deepwater region (> 800 m) in terms of the contamination of the biophase in both water layers. The contents of persistent organochlorine compounds like polychlorinated biphenyls (PCBs) in fish living in the upper water layers of the North Atlantic and the South Atlantic, and at the continental shelf of California (Marine Sanctuary Monterey Bay and its deep-sea Canyon) are compared to the levels in deep-sea or bottom dwelling fish within the same geographic area. The deep-sea biota show significantly higher burdens as compared to surface-living species of the same region. There are also indications for recycling processes of POPs--in this case the PCBs--in the biophase of the abyss as well. It can be concluded that the bio- and geo phase of the deep-sea may act similarly as the upper horizons of forest and grasslands on the continents as an ultimate global sink for POPs in the marine environment.  相似文献   

5.
Adolescent Brotia hainanensis collected from two separate sites along the same river showed markedly different acute responses to cadmium even after laboratory acclimation for one week. Similar interpopulation differences persisted in the F(1) juveniles (< two-day old) which were descendants of laboratory-cultured snails. Although these results could imply that the inter-site differences in cadmium tolerance for the two populations may have a genetic basis, these differences in metal tolerance in the F(1) juveniles disappeared after the juveniles had been cultured under identical laboratory conditions for one week. Quantitative genetical analyses revealed that variance of initial shell length and survival time of F(1) juveniles exposed to 10 mg/litre cadmium was significantly smaller for juveniles that were offspring of the same female as compared with animals that were descendants of different females. Moreover, the survival time was positively correlated with the initial size of the juveniles. Common environmental and maternal effects have an overwhelming influence on cadmium tolerance in these ovoviviparous snails.  相似文献   

6.
The Rhodophyceae (red algae) are an established source of volatile halocarbons in the marine environment. Some species in the Bonnemaisoniaceae have been reported to contain large amounts of halogens in structures referred to as vesicle cells, suggesting involvement of these specialised cells in the production of halocarbons. We have investigated the role of vesicle cells in the accumulation and metabolism of bromide in an isolate of the red macroalga Asparagopsis (Falkenbergia stage), a species known to release bromocarbons. Studies of laboratory-cultivated alga, using light microscopy, revealed a requirement of bromide for both the maintenance and formation of vesicle cells. Incubation of the alga in culture media with bromide concentrations below 64 mgl(-1) (the concentration of Br(-) in seawater) resulted in a decrease in the proportion of vesicle cells to pericentral cells. The abundance of vesicle cells was correlated with bromide concentration below this level. Induction of vesicle cell formation in cultures of Falkenbergia occurred at concentrations as low as 8 mgl(-1), with the abundance of vesicle cells increasing with bromide concentration up to around 100 mgl(-1). Further studies revealed a positive correlation between the abundance of vesicle cells and dibromomethane and bromoform production. Interestingly, however, whilst dibromomethane production was stimulated by the presence of bromide in the culture media, bromoform release remained unaffected suggesting that the two compounds are formed by different mechanisms.  相似文献   

7.
Environmental Science and Pollution Research - Many researchers and intellectuals focused on the topic of organizational citizenship behavior for the environment (OCBE); however, employees’...  相似文献   

8.
This study evaluates the follow-up trends in the composition and structure of the parasite communities in the marine sparid Boops boops after the Prestige oil-spill. A total of 400 fish comprising 11 seasonal samples was analyzed from three impacted localities on the Atlantic coast of Spain. A large number of parasite species was recovered only after the spill thus suggesting a substantial alteration of the marine food webs. Post-spill communities exhibited higher richness and abundance due to the significant changes in the abundance of the common species, the latter indicating accelerated parasite transmission rates. Multivariate analyses at two nested scales detected a directional trend in parasite community succession towards the pre-spill situation, however, with no full support for community recovery. The state of parasite communities in 2005-2006 may provide the new baseline data which can serve as a framework for quantifying the impact of potential future spills in the region.  相似文献   

9.
10.

Polyaromatic hydrocarbons (PAHs) are widely spread ecological contaminants. Antibiotic resistance genes (ARGs) are present with mobile genetic elements (MGE) in the bacteria. There are molecular evidences that PAHs may induce the development of ARGs in contaminated soils. Also, the abundance of ARGs related to tetracycline, sulfonamides, aminoglycosides, ampicillin, and fluoroquinolones is high in PAH-contaminated environments. Genes encoding the efflux pump are located in the MGE and, along with class 1 integrons, have a significant role as a connecting link between PAH contamination and enrichment of ARGs. The horizontal gene transfer mechanisms further make this interaction more dynamic. Therefore, necessary steps to control ARGs into the environment and risk management plan of PAHs should be enforced. In this review, influence of PAH on evolution of ARGs in the contaminated soil, and its spread in the environment, has been described. The co-occurrence of antibiotic resistance and PAH degradation abilities in bacterial isolates has raised the concerns. Also, presence of ARGs in the microbiome of PAH-contaminated soil has been discussed as environmental hotspots for ARG spread. In addition to this, the possible links of molecular interactions between ARGs and PAHs, and their effect on environmental health has been explored.

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11.

This paper discusses the effect of network infrastructure on environmental pollution reduction and the realization mechanism behind it. Based on the panel data of 285 cities in China from 2005 to 2019, this study regards the “Broadband China” pilot policy as a quasi-natural experiment to clarify the pollution emission reduction effect of network infrastructure construction through differences-in-differences method and other methods. The research results show the following: (1) The Broadband China pilot policy has reduced environmental pollution, that is, the construction of network infrastructure has the effect of environmental pollution reduction. The conclusion is still established after a series of robustness tests such as parallel trend test, placebo test, and instrumental variable method. Through the heterogeneity test, it is found that the pollution reduction effect of network infrastructure construction is more obvious in non-resource-based cities, first and second tier cities, and cities in the eastern region (2). The construction of network infrastructure plays a restraining role on local environmental pollution. Due to the insufficient level of regional linkage and the siphon effect of pilot cities, the spatial spillover characteristics of the pollution reduction effect are not obvious (3). The mechanism of action shows that green innovation is an important mediating effect mechanism for network infrastructure construction to reduce environmental pollution. Cities in regions with high degree of marketization and environmental regulation can strengthen the effect of network infrastructure construction on environmental pollution reduction. The research conclusions are conducive to accelerating the development of the digital economy represented by the construction of network infrastructure and provide a useful reference for promoting the level of environmental pollution reduction and achieving high-quality development.

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12.
Environmental Science and Pollution Research - Concentrations of 22 essential and non-essential trace elements (Be, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Ag, Cd, Sb, Ba, Tl, Pb, Th, U, and...  相似文献   

13.
Levels of eight PCB congeners and thirteen organochlorine pesticides were measured in eggs sampled at four yellow-legged gull colonies from the Aegean Sea (NorthEastern Mediterranean) in 1997. There were no significant differences among colony areas in the median concentrations in any of the pollutants whereas cluster analyses did not generally reveal reasonable pollution patterns. The maximum concentrations of four congeners were found at Kinaros colony and of nine compounds were found at Lipsos colony. Fingerprints in both groups were similar in all areas. Of PCBs, congener 28, 118, 138, 180 and of pesticides beta-BHC and 2,4'-DDD were prominently dominant suggesting a particular pollution pattern in this region. Statistically significant correlations were found between most of the higher PCBs in all areas studied. The DDT metabolites correlated mostly with other OCs. We suggest that regional pollution by both groups is not adequately reflected in the eggs of this gull probably due to its extensive scavenging habits and, though information is needed from more colonies, it seems to be a poor biomonitor for organochlorines in this region.  相似文献   

14.
The understanding of the global environmental multiphase distribution of persistent organic pollutants (POPs) as a result of the physico-chemical properties of the respective compounds is well established. We have analysed the results of a vertical transport of POPs from surface water to deepwater in terms of the contamination of the biota living in the respective environmental compartments. Samples were taken from the North and the South Atlantic and from the uprising water region of the continental shelf of California (Marine Sanctuary Monterey Bay and its Canyon). The contents of persistent organochlorine pesticides (DDTs, chlordanes, toxaphenes, HCHs, and HCB) in surface-living fish are compared to those in deepwater fish of the same geographic area. The deepwater biota show significantly higher burdens as compared to surface-living species of the same region. There are also indications for recycling processes of POPs of the class of organochlorine pesticides in the biophase of the abyss as well. It can be concluded that the bio- and geophase of the deep-sea may act as an ultimate global sink for persistent semivolatile contaminants in the marine environment like the soil on the continents.  相似文献   

15.
16.
The assessment of the direct impact of breakdown products of pesticide components on aquatic wildlife is ecotoxicologically relevant, but frequently disregarded. In this context, the evaluation of the genotoxic hazard posed by aminomethylphosphonic acid (AMPA—the major natural degradation product of glyphosate) to fish emerges as a critical but unexplored issue. Hence, the main goal of the present research was to assess the AMPA genotoxic potential to fish following short-term exposures (1 and 3 days) to environmentally realistic concentrations (11.8 and 23.6 μg L?1), using the comet and erythrocytic nuclear abnormalities (ENA) assays, as reflecting different levels of damage, i.e. DNA and chromosomal damage, respectively. Overall, the present findings pointed out the genotoxic hazard of AMPA to fish and, subsequently, the importance of including it in future studies concerning the risk assessment of glyphosate-based herbicides in the water systems.  相似文献   

17.
In situ benthic flux experiments were conducted at two stations in the Mar Piccolo of Taranto (Italy), one of the most industrialised and contaminated coastal areas of the Mediterranean. Sediments of the two stations are notably different in their trace metal content, with a station closer to a Navy harbour showing higher mean concentrations of almost all investigated metals (Al, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, V and Zn). Conversely, both stations are characterised by significant Hg contamination, compared to the local baseline. Results of a sequential extraction scheme on surface sediments suggest a relatively scarce mobility of the examined metals (Zn > Ni > Cr > As > Cu > Pb). A Hg-specific extraction procedure showed that most of the element (93.1 %) occurs in a fraction comprising Hg bound to Fe/Mn oxi-hydroxides. Reduction of these oxides may affect Hg remobilisation and redistribution. Porewater profiles of dissolved trace metals were quite similar in the two sites, although significant differences could be observed for Al, Cu, Fe and Hg. The highest diffusive fluxes were observed for As, Fe and Mn. Mobility rates of several trace elements (Al, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, V and Zn) were directly measured at the sediment–water interface. Results from benthic in situ incubation experiments showed increasing dissolved metal concentrations with time, resulting in higher fluxes for Cu, Fe, Hg, V and Zn in the most contaminated site. Conversely, fluxes of Mn, Ni and Pb were comparable between the two stations. The estimated flux of Hg (97 μg m?2 day?1) was the highest observed among similar experiments conducted in other highly contaminated Mediterranean coastal environments. Benthic fluxes could be partially explained by considering rates of organic matter remineralisation, dissolution of Fe/Mn oxy-hydroxides and metal speciation in sediments. Seasonal and spatial variation of biogeochemical parameters can influence metal remobilisation in the Mar Piccolo area. In particular, metals could be promptly remobilised as a consequence of oxygen depletion, posing a serious concern for the widespread fishing and mussel farming activities in the area.  相似文献   

18.
Environmental Science and Pollution Research - Roundup Transorb® (RDT) is a glyphosate-based herbicide commonly used in agricultural practices worldwide. This herbicide exerts negative effects...  相似文献   

19.
Current European Union regulation regarding polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in food and feed is based on Toxic Equivalent Quotient (TEQ) concept. For confirmatory purpose, the isotope-dilution method associated to a measurement by gas chromatography coupled with high resolution mass spectrometry is usually the method of choice for precisely measuring the 29 target congeners in three separated fractions. Time and cost related to these analyses are very significant. Various kinds of screening concepts can be considered. In the present study, we elaborated and validated a prediction model for the 2005 World Health Organization TEQ in fish, based on the measurement of 4 PCDD/F and 2 non-ortho dl-PCB congeners, potentially analyzable in a single extracted fraction by gas chromatography coupled with mass spectrometry. Large independent datasets have been used for model elaboration (n = 108) and validation (n = 363, n = 357 and n = 6).  相似文献   

20.
The present work compares the efficiency of homogenous Fenton and photo-Fenton processes in the presence of Fe(III)–EDDS complex under different experimental conditions. 4-tert-Butylphenol (4-t-BP), which is one of the endocrine disrupting chemicals, was used as a model pollutant to investigate the Fenton and photo-Fenton application. The efficiency of homogenous photo-Fenton process was significantly much higher than homogenous Fenton process, which is due to the rapid formation of Fe2+ under UV irradiation of the iron complex and the photochemical formation of HO? from the photolysis of the complex Fe(III)–EDDS. Through the degradation of 4-t-BP, the effect of Fe(III)–EDDS concentration, H2O2 concentration, pH, and oxygen was investigated in both processes. Such trend was also correlated with pH calculating the polychromatic Fe2+ quantum yield formation at pH 4.0, 6.0, and 8.6. The results showed that at high Fe(III)–EDDS and H2O2 concentrations, a negative effect was found. By the way, the Fenton process was found to be enhanced at basic pH. These results can be very useful for the use and optimization of such iron complex in water treatment process as function of different physico-chemical conditions.  相似文献   

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