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1.
Nuclear bud (NB) formation was investigated in blood erythrocytes of 1892 flounder Platichthys flesus, herring Clupea harengus, and eelpout Zoarces viviparus specimens that were collected at 82 sites representing different regions of the Baltic Sea in 2009–2011. This is the first attempt to evaluate the baseline levels of NB and rank the genotoxicity risk for native fish species. NB levels were compared to the previously published micronuclei (MN) data from the same individual fish specimens in order to compare the two methods of genotoxicity assessment and investigate the relationship between MN as the cytogenetic measure of genotoxicity and the DNA damage reflecting NB. In 2009–2011, elevated NB levels in 89.4 % of flounder sampling groups indicated high and extremely high genotoxicity risk levels. Herring and eelpout sampling groups showed elevated levels of NB, 74.6 and 45.7 %, respectively. In general, herring and eelpout NB measure was more sensitive as the genotoxicity biomarker than MN.  相似文献   

2.
Cotton workers are recognized as being at risk of developing occupational lung diseases. Some researchers have identified endotoxins as being a potential etiologic agent for some of the respiratory problems. This study wants to document the concentration of endotoxins found in the ambient air of textile mills where cotton fibers are handled and to identify the processing steps where the highest endotoxins concentrations in the air were found and the one where the relative limit values (RLVs) are exceeded. The 4 mills studied process cotton fibers. All the air samples were analyzed using the chromogenic Limulus Amoebocytes lysate LAL method using a kinetic detection principle based on the IRSST's standard method. In this study, a large variability in the concentrations of endotoxins in the air was observed, depending on the mill, the processing step, and the time. Despite these variations, some processes can be identified as being major generators of endotoxins in the ambient air of the mills. The highest concentrations were measured in the weaving and drawing processes and reached 10,000 EU m(-3) of air. The opening, cleaning, carding, spinning and drawing processes are the other major endotoxins generating processes with concentrations from 24 to 8,700 EU m(-3) of air. The endotoxins concentrations exceeded the RLVs for 55% of the workstations in this project. This study demonstrated that endotoxins levels in the cotton industry are high and appropriate control measures are needed.  相似文献   

3.
Hunting is a problem to animal conservation in different parts of the world and it has caused the local extinction of several species. The aim of this study was to characterize the poaching activities in one of the main tabuleiro forest remnants of Brazil, the Linhares-Sooretama Block (LSB). Poaching records from 2010 to 2013 were gathered from the agencies responsible for monitoring and combating environmental crimes in the LSB. A total of 693 records (mean = 173 events/year) were collected involving direct (hunted animals, firearms, handmade firearms, traps, poachers, and various hunting supplies) and indirect (tree stands, baits, and poacher signs) evidences of poaching. No differences in the monthly cumulative number of records were found among years, but the distribution of records differed according to the type of evidence. A total of 40 animal seizure events were recorded involving a total of at least 15 taxa directly affected by poaching (reptiles = 2, birds = 6, mammals = 7) and 75 individuals seized (19 individuals/year). Five of the poached species are threatened. Lowland paca (Cuniculus paca) and armadillos were the most poached mammals in the region. Most of the poachers conduct such activities for fun (entertainment) and/or professionally (commercial hunting). The collected data show an approximately 32% increase in the number of poaching events in the region compared with the historical data available for LSB. It may have resulted from a gradual decrease in protection, both in terms of the number of agents deployed and the levels of effort of the teams, which began in 2009. The data demonstrate that poaching is a significant threat to the conservation of the LSB fauna, as it is in other Atlantic Forest remnants and in other regions of the world. Protection activities must be intensified to effectively combat the impacts of poaching in the LSB region, thereby contributing to the conservation of species in one of the few Atlantic Forest remnants whose original species composition still remains intact.  相似文献   

4.
The distribution and accumulation of trace metals in the sediments of the Cochin estuary during the pre-monsoon, monsoon and post-monsoon periods were investigated. Sediment samples from 14 locations were collected and analysed for the metal contents (Mg, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd and Pb), organic carbon, total nitrogen, total sulphur and grain size. The data were processed using statistical tools like correlation, factor and cluster analysis. The study revealed an enrichment of Cd and Zn in the study area particularly at station 2, which is confirmed by enrichment factor, contamination factor and geoaccumulation index. The factor analysis revealed that the source of Cd and Zn may be same. The study indicated that the spatial variation for the metals like Mg, Cr, Fe, Co, Ni, Cu, Zn, Cd and Pb were predominant unlike Mn which shows a temporal variation. The strong association of trace metals with Fe and Mn hydroxides and oxides are prominent along the Cochin estuary. The anthropogenic inputs of industrial effluents mainly control the trace metals enrichment in the Cochin estuary.  相似文献   

5.
The first paleoecological reconstruction of the biogeochemical conditions of the Gulf of Batabanó, Caribbean Sea was performed from (210)Pb-dated sediment cores. Depth profiles of 20 major elements and trace metals, organic compounds, grain size, and mollusk assemblage composition were determined from 9 stations encompassing unconsolidated sediments in the gulf. Spatial heterogeneity was evident for the geochemistry of sediments and for the mollusk assemblage composition. Our reconstruction indicates that pollution is not a critical threat to the ecosystem, although a slight historical increase of lead enrichment factor was detected probably due to long-range atmospheric fallout. Mollusk assemblages were composed by 168 species belonging to 59 families and no temporal trends in the species diversity or assemblage composition were detected, suggesting no depletion of diversity or habitat loss. Other signals of habitat loss such as changes in organic budget or increase of fine sediment fraction were absent or weak. Nitrogen retained in sediments changed by <1% in the century, indicating no historical events of eutrophication or oligotrophication in the gulf. Historical decrease of fine sediment fraction in the eastern sector would be linked to modifications in sedimentation rate, land use, and/or particle transport from the shelf border; this also suggests that both sectors have different sedimentary dynamics. Although, on theoretical grounds, historical fishery may have caused deleterious ecosystem effects by overexploitation of spiny lobster stocks, no evidence of habitat degradation or loss, caused by fisheries, could be detected.  相似文献   

6.
The desertification risk affects around 40% of the agricultural land in various regions of Romania. The purpose of this study is to analyse the risk of desertification in the south-west of Romania in the period 19842011 using the change vector analysis (CVA) technique and Landsat thematic mapper (TM) satellite images. CVA was applied to combinations of normalised difference vegetation index (NDVI)-albedo, NDVI-bare soil index (BI) and tasselled cap greenness (TCG)-tasselled cap brightness (TCB). The combination NDVI-albedo proved to be the best in assessing the desertification risk, with an overall accuracy of 87.67%, identifying a desertification risk on 25.16% of the studied period. The classification of the maps was performed for the following classes: desertification risk, re-growing and persistence. Four degrees of desertification risk and re-growing were used: low, medium, high and extreme. Using the combination NDVI-albedo, 0.53% of the analysed surface was assessed as having an extreme degree of desertification risk, 3.93% a high degree, 8.72% a medium degree and 11.98% a low degree. The driving forces behind the risk of desertification are both anthropogenic and climatic causes. The anthropogenic causes include the destruction of the irrigation system, deforestation, the destruction of the forest shelterbelts, the fragmentation of agricultural land and its inefficient management. Climatic causes refer to increase of temperatures, frequent and prolonged droughts and decline of the amount of precipitation.  相似文献   

7.
In many coastal countries, oil spill contingency plans include several alternatives for removal of the spilled oil from the ocean. Frequently, these plans include dispersants. Because this process applies chemical substances that may add toxicity to oil that already contains toxic compounds, it is, at times, a controversial method to fight oil pollution. Additionally, local conditions may result in particular complications. We investigated the possible effects of the dispersant Corexit 9500© under conditions similar to those of subtropical oceans. We used fuel oil #6+ diesel as the test mixture. Under certain conditions, at least part of the dispersed oil may reach the sediment, particularly if the dispersant is applied in coastal waters. Nine experimental units were used in this experiment. Similar conditions of water temperature, salinity, air fluxes into the experimental units, and hydrocarbon concentrations in sediments were used. Two treatments and one control, each one with three replicates, were carried out. We concentrated our investigation on sediment, although measurements of water were also taken. Our results suggest that once the oil has penetrated the sediment, no significant differences exist between oil that contains dispersant and oil without dispersant. Noticeable degradation of aliphatic hydrocarbons occurred mainly in the low molecular weight aliphatic hydrocarbons and not in the others. Apparently, degradation of aromatics was easier than that of alkanes. However, some differences were noticed for the degradation of PAHs in the sediment, suggesting a faster degradation under particular conditions in aerobic environments such as under this experiment.  相似文献   

8.
The Dutch National Monitoring Programme for Effectiveness of the Minerals Policy (LMM) was initiated to allow detection of a statutory reduction in nitrate leaching caused by a decreasing N load. The starting point, or baseline, was taken as the nitrate concentration of the upper metre of groundwater sampled on 99 farms in the 1992–1995 period in the sandy areas of the Netherlands, where predominantly grass and maize grow. We found here that a reduction in nitrate leaching of more than 20% in future would almost certainly be detected with the LMM. Detecting downward trends due to decreasing N load will require nitrate concentrations to also be related to soil drainage, precipitation excess leading to groundwater recharge and to location. Furthermore, we found that about 16% of the N load in the Dutch sandy regions was being leached to the upper metre of groundwater in the 1992–1995 period. The critical N load in approximately 1990 for exceeding the EC limit value for nitrate, NO3, (50 mg L–1) in the upper metre of groundwater for the mean situation for grassland, maize and arable land in the sandy area was found to be 210 kg ha–1 a–1. Because manure management has been altered, the critical load found will be lower than the current critical load .  相似文献   

9.
The pollutants that are discharged from roads and traffic have attracted much attention recently. Nonetheless, most studies have mainly focused on highways and seldom on railways. In this study, soil samples were selected at the embankment and perpendicularly at different distances (2, 5, 10, 20, 30, 50, 60, 70, 80, 100, and 150 m) from the embankment bottom of the QinghaiTibet railway. Furthermore, soils were selected at four soil depths (5, 10, 20, and 30 cm) of each sample at the flat. The enrichment of nine heavy metals (V, Cr, Co, Ni, Cu, Zn, Rb, Cd, and Pb) in soils along the DelhiUlan section of the QinghaiTibet railway was studied. The results indicated that the mean concentrations of Cr, Ni, Cu, Zn, Pb, and Cd were highest at the embankment. The Cu concentrations in soils decreased by an S-curve-shaped function with increasing distance from the embankment, while Cd, Pb, and Zn decreased by inverse functions (p?<?0.0001). The concentrations of other studied metal did not show significant changes with increasing distance. After performing a statistical analysis, Pb, Cd, and Zn in soils were considered to be influenced by railway operations. However, the influence was weak and only spanned less than 5 m from the bottom of the embankment horizontally and 10 cm from the surface vertically. The mean concentrations of heavy metals in soils along the DelhiUlan section of the QinghaiTibet railway were considered lower compared with those along other railways.  相似文献   

10.
Concentrations of heavy metals were determined in the water column (including the sea-surface microlayer, subsurface, mid-depth and bottom water) and sediments from Singapore’s coastal environment. The concentration ranges for As, Cd, Cr, Cu, Ni, Pb and Zn in the seawater dissolved phase (DP) were 0.34–2.04, 0.013–0.109, 0.07–0.35, 0.23–1.16, 0.28–0.78, 0.009–0.062 and 0.97–3.66 μg L−1 respectively. The ranges for Cd, Cr, Cu, Ni, Pb and Zn in the suspended particulate matter (SPM) were 0.16–0.73, 6.72–53.93, 12.87–118.29, 4.34–60.71, 1.10–6.08 and 43.09–370.49 μg g−1, respectively. Heavy metal concentrations in sediments ranged between 0.054–0.217, 37.48–50.52, 6.30–21.01, 13.27–26.59, 24.14–37.28 and 48.20–62.36 μg g−1 for Cd, Cr, Cu, Ni, Pb and Zn, respectively. The lowest concentrations of metals in the DP and SPM were most frequently found in the subsurface water while the highest concentrations were mostly observed in the SML and bottom water. Overall, heavy metals in both the dissolved and particulate fractions have depth profiles that show a decreasing trend of concentrations from the subsurface to the bottom water, indicating that the prevalence of metals is linked to the marine biological cycle. In comparison to data from Greece, Malaysia and USA, the levels of metals in the DP are considered to be low in Singapore. Higher concentrations of particulate metals were reported for the Northern Adriatic Sea and the Rhine/Meuse estuary in the Netherlands compared to values reported in this study. The marine sediments in Singapore are not heavily contaminated when compared to metal levels in marine sediments from other countries such as Thailand, Japan, Korea, Spain and China.  相似文献   

11.
The De?le River in Northern France experienced serious contamination from the metallurgical industry, especially from the smelter Metaleurop prior to 2003. In 2002 the surface sediments were collected from the bed of the river around 10 km above and 10 km below the smelter. Total mercury (HgT) and methylmercury (MeHg) concentrations exceeded the background value of 0.1 mg kg(-1). The average concentrations were 19.67 ± 1.02 mg kg(-1) and 10.88 ± 1.08 μg kg(-1), respectively. In 2003 the sediment core samples were collected at two different sites near the factory for survey depth profiles of Hg contamination. The concentrations of HgT and MeHg in sediment cores varied from 10.47 to 259.44 mg kg(-1) and from 3.24 to 82.61 μg kg(-1), respectively. The concentration of total mercury was significantly correlated with the methylmercury concentration in the sediment below a depth of 23.5 cm (R(2) = 0.81, p < 0.01). This may suggest that the production of MeHg is directly related to the HgT concentration. Nevertheless the MeHg/HgT ratio in the upper part of the sediment core was higher than that in the lower part. This suggests that HgT and MeHg may have been co-deposited together. However, the methylmercury production takes place in the surface sediment by microorganisms. The strong correlation observed between MeHg and acid volatile sulfides (AVS) suggests that MeHg variability is associated with the bacterial activity (presence of AVS).  相似文献   

12.
Waste incineration power plants have become the best option in face of the increasing amount of garbage in China's cities. However, constructing waste incineration power plants will cause “not in my backyard” (NIMBY) effect in the public. To identify variables causing this effect and measure the effect quantitatively, we designed and carried out a random survey in four metropolises in China. Of the 3133 questionnaires distributed, 3066 are thought to be effective. Males, persons with higher educational levels, or with higher income, or having underaged children in their families, or thinking their neighborhoods are upscale ones are willing to pay more to avoid the construction of waste incineration power plants in their surroundings than others. In addition, provided that the respondents deem that the construction of waste incineration power plants would have an impact on their lives, they are willing to pay more no matter they own their departments or not. Finally, the estimated willingness to pay (WTP) to avoid the waste incineration power plants is 105 yuan to 133 yuan per month. Hence, the government should treat the NIMBY syndrome well in the construction of waste incineration power plants, with WTP being one perspective to persuade the public.  相似文献   

13.
The chemical speciation analysis of chromium in one of the most important South American Estuary was performed for the first time. Samples were collected in Patos Lagoon Estuary (Brazil) and were analysed by adsorptive cathodic stripping voltammetry, with the following analytical figures of merit: limit of detection, 0.1 nmol L(-1); precision RSD?=?3%, n?=?7; linearity, from limit of quantitation up to 20 nmol L(-1); and accuracy of 99.8%, expressed as recovery. No labile chromium forms were identified in samples, beside industries and a city were near the study area. It is pointed out a reverse correlation between total and non-active chromium and salinity, which could be explained by biogeochemical processes.  相似文献   

14.
This study deals with numerical simulation of flow fields and dispersion of model passive admixtures in the planetary boundary layer in a 10 × 10 km square area, centered on the Czech Republic’s Temelín Nuclear Power Plant. Numerical calculations of three-dimensional flow fields with eight basic wind directions given for the inlet boundary of the computational domain are performed using the FLUENT CFD code with the standard kε turbulence model. The resultant modeling of the flow fields provides information as to probable local directions and velocities of flow vectors on a horizontal scale of 100 m, which are consistent with the data given for the boundaries of the calculation area in the framework of a scale of 10 km. The modeled flow fields generate the input data for related Lagrangian simulation of the ground concentration and deposition fields of passive particles assumedly emitted at the site of the Temelín plant. Simulated plumes describe eight cases of potential ground-level distribution of model passive admixtures in the area.  相似文献   

15.
A 5-day biochemical oxygen demand (BOD(5)) test has been used as the standard measurement of organic pollution in rivers worldwide. However, it may be argued that BOD is not a sufficient indicator of organic pollution when nitrogenous biochemical oxygen demand (NBOD) is present in water samples. In this study, BOD, NBOD, and carbonaceous biochemical oxygen demand (CBOD) of treated sewage effluent (TSE) were measured near at the discharge outlet of 3 sewage treatment plants (STPs) in Sakai, Itachi, and Kashio rivers in Central Japan. Additional measurements were conducted at one point upstream and two points downstream from the STP discharge points in the rivers. It was estimated that NBOD values in the TSE of Sakai River, Kashio River and Itachi River accounted for 54%, 69% and 18% of their BOD values, respectively. Respective NH4+ and NO2- concentrations were positively correlated with those of NBOD values in Sakai, Itachi, and Kashio rivers. The BOD loads from the TSE were estimated to be 2.2, 5.7, and 1.2 times higher than the CBOD loads in the Sakai, Itachi, and Kashio rivers, respectively. The variation of the portion of NBOD values of each TSE, as well as the ratios of CBOD to BOD loads, was attributed to the difference in each STP system. Consequently, the NH4+ and NO2- of TSE led to the increase of NBOD in the Sakai River basin.  相似文献   

16.
Changing the concepts of economic development and introducing new amendments can hardly decrease the accumulation in the soil of such pollutants as metals, remaining there for a long time. The predictive models for describing the balance of metals in the soil, which are based on the ‘atmosphere–plant–soil’ system and reflect the complicated physical–chemical nature of the metals’ migration, expressed by coefficients obtained in long-term observations in natural conditions, allow for evaluating long-term concentration of metals in the soil. The model BALANS evaluates self-purification of soil, taking into account the uptake of metals of aerogenic origin by the soil together with amendments, their physical–chemical migration and the type of microrelief determining its intensity as well as the absorbed biomass of plants and the removal of metals with crops. In this model, the half-period of metals’ washing out from the soil, found for the microrelief characteristic of low places, exceeds 200 years for Ni, Cr and Pb and makes 90 and 150 years for Zn and Cu, respectively.  相似文献   

17.
The geochemistry of coastal sediments of southern India was altered after the tsunami in 2004. A five-step sequential extraction procedure was applied to assess the effects of tsunami on mobility and redistribution of selected elements (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn). Ten surface sediments and three cores were analyzed for different metal fractions (exchangeable, carbonate, reduced, oxidized, and residual). Total metal concentrations increased in mangrove sediments after the tsunami, but their spatial distribution did not show significant variation (except Mn). The sediments were mixed by the tsunami, and there was lack of variation in metal concentrations in different fractions with depth (except Pb and Mn). High concentrations of Pb and Zn occurred in the oxide fractions, whereas Cu, Cr, Cd, and Ni were high in the organic and sulfide-rich fractions. Metals in the residual fraction (lattice bound) had the highest concentration suggesting their non-availability and limited biological uptake in the system. Most of the metals (except Mn) do not constitute a risk based on the different geochemical indices.  相似文献   

18.
The purpose of this study was to evaluate the impact of acid mine drainage on the chemistry and the macrobenthos of the Carolina stream (San Luis – Argentina). Samples were obtained in the years 1997–1998 at two sites: site C1, located 200 m upstream of the drainage, and site C2, located 800 m downstream. The system buffer capacity was evaluated in the non – contaminated site by means of the buffer index calculation. The physico – chemical changes observed as a consequence of the contribution of acid mine drainage (AMD) were: a decreasing of pH and an increase in the ionic concentration, especially sulfate and Fe coming from the oxidation produced by chemiolithotrophic bacteria. The values obtained indicated a low buffer capacity and a high intrinsic vulnerability of the system to resist the impact originated by the AMD, producing a remarkable decreasing of pH of the receiving stream. These changes caused modifications in the original benthic community that was replaced by organisms more tolerant to the acid stress. A reduction in the abundance and in the taxonomic richness of the benthic macroinvertebrates was observed when compared with the reference station. An increase in the proportion of Chironomidae and of Acari and a decrease in the proportion of the remaining taxa were observed. The most sensitive groups were Ephemeroptera, Trichoptera and Mollusca. The community was mostly affected by the following variables: pH, conductivity, sulfate and dissolved total Fe.  相似文献   

19.
The aim of this study was to analyse the relationship between the distribution of hay-fever patients in the city of Córdoba, south-western Iberian Peninsula, and the specific atmospheric biological content originating from local sources. Four different districts were established in the metropolitan area of the city, according to vegetational and urbanistic characteristics. Air samples were taken in each area using portable Hirst-type samplers (Lanzoni VPPS 1000) and the spectrum of biological content was defined. Patients attending the Allergy Unit at Córdoba Teaching Hospital in 2000 with allergic rhinitis and/or asthma, and displaying a positive reaction to aeroallergen extracts, were distributed within the areas as a function of their district of residence. Aerobiological results revealed differences in pollen content between areas, in terms of both quantity and number of pollen types recorded. These differences were largely due to proximity to rural areas, prevalence of pollen from typically urban species and the possible effect of urban architecture as a barrier to the dispersal/ concentration of particles and other pollutants. Patients were not uniformly distributed within the city. The majority lived in districts in which pollen from rural species was mixed with pollen from ornamentals. Patients living in typically urban districts displayed a higher prevalence of allergy to pollen from ornamentals. It is concluded that a high degree of exposure to the same environment may influence the development of sensitisation to the particular pollen load associated with that area.  相似文献   

20.
To meet the growing energy demand worldwide, oil and gas exploration and production activities have increased rapidly both in onshore and offshore areas. The produced oil from the ocean bed is transported onshore either by ship or pipeline. This has increased the risk of oil spill in the coastal area. In order to prepare an emergency preparedness plan and to assess the magnitude of risk involved in transporting and offloading oil, oil spill simulation studies play an important role. This paper describes a simulation of oil spill in coastal bay of Arabian Gulf where new developments are taking place using MIKE 21 model. The developments include a diesel based thermal power plant near Sir Baniyas Island, which is an ecological fragile area. Based on the project activity, two probable scenarios, one for diesel leak (250 m3/h) for 1 h and the other for instantaneous spill (500 m3) are considered. The MIKE 21 model was calibrated for hydrodynamics using measured field data followed by diesel-spill simulation to track its movement in the Arabian Gulf. The results for both leak and instantaneous spill indicate that spilled diesel will not move towards the Sir Banyas Island and more than 45% of the diesel will be evaporated within 48 h of oil spill. Based on the results, a clean up and contingency plan is proposed to mitigate the adverse impacts arising due to diesel spill in the study area.  相似文献   

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