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1.
This study examined the role of gas flaring in the rapid corrosion of zinc roofs in the Niger Delta Region of Nigeria. Four experimental sites were set up where samples of galvanized iron sheet (popularly called “zinc roofs”) were exposed to the atmosphere. The corrosion behaviour of galvanized iron sheet through weight loss determination under different environmental conditions was monitored. A uniform angle of inclination of 22° (which represents the mean angle of inclination of house roofs in the study area) was chosen. The results showed that corrosion was more severe (average readings of 25.89, 34.30, and 21.27 mg) in the three experimental sites that were located near pollution sources such as gas flare station or sea aerosols, than at the controlled site (2.36 mg) that was located far away from pollution sources. It is recommended that government’s policy of zero gas flaring for oil companies operating in the Niger Delta by 2010 be pursued with vigour, so as to realize the deadline and subsequently reduce the economic burden currently suffered by the inhabitants of the Niger Delta through frequent replacement of house roofs and incessant illnesses. In addition, individuals and companies operating in the region should avoid bush burning, reduce the rate of fossil fuel consumption by conserving energy, and install catalytic converters in cars and industrial chimneys, so as to reduce emissions.  相似文献   

2.
Gas flaring is the burning of crude oil’s associated gas. In Nigeria’s Niger Delta, the flaring process is usually very close to communities and their farmlands and has been implicated in serious environmental degradation of the region. Studies have suggested links between gas flaring and health problems in the communities and others have established relationships between gas flaring and poor agricultural yields. This study explores how the people in the region perceive gas flaring and what their attitudes are toward it. Ubeji town, a community where gas flaring takes place, was selected as a case study. It was found that the residents perceive gas flaring as hazardous to health, environment, and general well-being of the community. Most residents seem to be resigned to the continued presence of gas flaring activities in the community. The study, however, raised several questions on modeling perception and attitudes toward environmental problems in areas where political tension and economic adversity are prevalent.  相似文献   

3.
Small mammals are important predators of gypsy moths (Lymantria dispar L.), which are major defoliators of deciduous forests in the northeastern United States. Abundance and habitat relationships of small mammals were studied during summers 1984 and 1985 on forested sites at Moshannon and Rothrock state forests in two physiographic regions of Pennsylvania (Allegheny High Plateaus Province and Valley and Ridge Province, respectively) that varied in potential susceptibility to defoliation. The white-footed mouse (Peromyscus leucopus), which is a major vertebrate predator of gypsy moths, was the most common small mammal on all sites. Of the four common species, northern short-tailed shrews (Blarina brevicauda), southern red-backed voles (Clethrionomys gapperi), and white-footed mice were more abundant at Moshannon compared to Rothrock State Forest, but masked shrews (Sorex cinereus) were more abundant at Rothrock. Elevation was a major factor affecting abundance and distribution of small mammals. Because of the greater abundance of small mammals and more suitable physiographic features at Moshannon compared to Rothrock State Forest, small mammals may be more effective as predators on gypsy moths in the Allegheny High Plateaus than the Valley and Ridge Province of Pennsylvania.  相似文献   

4.
Environmental Pollution now persist in Nigeria especially the oil-rich regions of Delta State. One of these problems is due to gas flaring. Thermal gradient resulting from the gas flared at Kwale/Okpai gas plant is hereby reported. Surface temperature variations with distance from the flare point were investigated for the four cardinal directions. The results show a surface temperature elevation of about 3.7° C above the mean normal daily temperature within a radius of 270 M. Hence the thermal equilibrium has been altered. This increase in temperature has undesirable effect on man and his environment especially on the socio-economic lives and activities of the inhabitants. It is therefore necessary that Government Agencies empowered to monitor environment such as Federal Environmental Protection Agency (FEPA) should embark on adequate remediation activities in order to stop the environmental degradation before enormous and permanent damage is caused. Furthermore, the companies involved in the gas flaring should be made to be concerned with the danger they may be causing the inhabitants in particular and the populace in general.  相似文献   

5.
Dissolved copper was toxic to wild rice (Zizania palustris) seedlings when exposed in water from the seed collection site of Swamp Creek, Crandon, Wisconsin, USA, and in laboratory-prepared artificial or reconstituted water. Seeds for the study were harvested, then held through a portion of dormancy, in Swamp Creek. After 60 days they were shipped to a laboratory, chilled, and tested with copper after germination. The end point of the tests was net gain in wet weight of the seedlings; additionally, a pronounced reduction in root development was observed. Using measured concentrations, the lowest no-observable-effect concentration (NOEC) in our study was 37 g/liter in Swamp Creek water and the lowest-observable-effect concentration (LOEC) was 59 g/liter. However, it appeared that there was a point at which concentrations of copper above 400 g/liter did not result in any measurable effect or exhibit a definitive dose–response. Because the results in Swamp Creek water were more relevant to the possibility of local metals additions and the association of reduced seedling growth by copper was more powerful in this water, we derived an equation to express the relationship between copper concentration and toxicity for Swamp Creek water. As an example, we would expect a 3.0% reduction in seedling growth at 5.0 g/liter copper. Seedling roots were particularly affected and the resultant plants may be less well anchored and more susceptible to dislodging than plants not exposed to copper. Further refinement of the methodology may be used to address effects of other contaminants impacting rice beds in North America. This study was conducted while the first author was employed by the U.S. Geological Survey, Mid-continent Ecological Science Center, Fort Collins, Colorado  相似文献   

6.
Fresh whole plants of Pistia stratiotes were exposed to varying doses of crude oil (0–100 ppm) for 28 days at normal temperature of 30 ± 2°C. Samples were taken weekly during this period for determination of changes in leaf area, root length, number of leaves, and number of sprouts. The cross-section of one terminal end of the major roots and cellular distribution of the meristematic region were also examined. The results show that crude oil was toxic to the plant at all concentrations in all investigated parameters for as low as 10 ppm. Association was also observed between crude oil toxicity and certain metals inherent in the crude oil such as manganese and lead. Cell shape disruptions, changes in mitotic indices, and the distortion of cellular anatomy and structure at the apical region also characterized the presence of crude oil in the environment of P. stratiotes. P. stratiotes may not be a good bio-accumulator of crude oil but may be used for the detection of pollution.  相似文献   

7.
The increasing number of incidences of alleged wildlife poisoning with Furadan in Kenya has sparked off a strong lobby fronted by wildlife conservationists against Furadan use in the country and prompted this study. The worst-case scenario was in 2004 in Athi River, where a massive number of 187 African white-backed vultures (Gyps africanus) and hyenas were found dead at a spot where poisoning was suspected to have occurred through a Furadan-laced camel carcass bait. This study was initiated by the Peregrine Fund—Africa Project, and the objective was to provide evidence for Furadan exposure, its misuse and involvement in vulture poisoning and potential impact on areas near two wildlife conservancies in two most affected districts. The study found evidence for ready availability of Furadan 5G in local veterinary retail shops and its illegal misuse by pastoralists and farmers against wildlife to protect their animals and crops. Analysis of soil, water and plants taken from the farms and water sources by high-perfomance liquid chromatography (HPLC) and gas liquid chromatography–mass spectrometry (GC–MS) found residues of carbofuran, 3-hydroxycarbofuran and 3-ketocarbofuran, indicating that Furadan was used extensively in farming causing residual environmental distribution and contamination and posing risks to small birds and mammals. Forensic analysis of residues in beaks, feet and crop content of the dead vultures as well as in a laced camel carcass bait and soil samples from one site of poisoning also showed carbofuran and its two metabolites supporting allegations of Furadan involvement in wildlife poisoning and high-mortality cases of African white-backed vultures (Gyps africanus) in Kenya.  相似文献   

8.
In the present research, the effects of static magnetic field, with or without iron on the growth, the activity of certain enzymes (like polyphenol oxidase and phenyle alanine ammonialyase), the content of phenolic compounds and the essential oil composition of sweet basil (Ocimum basilicum) were studied. Treatment of plants with static magnetic field with or without iron led to decrease of the growth of plants as well as decrease in the activity of phenyle alanine ammonialyase and of phenolic compounds content. In addition in those plants exposed to magnetic field the amount of essential oils, notably of methyl chavicol, was increased. Exposure of plants to the magnetic field decreased the activity of polyphenol oxidase, whereas treatment of plants with iron when exposed to magnetic field increased polyphenol oxidase activity. In this group the content of essential oil was reduced.  相似文献   

9.
China has laid out an ambitious strategy for developing its vast shale gas reserves. This study developed an input–output based hybrid life-cycle inventory model to estimate the energy use, water consumption, and air emissions implications of shale gas infrastructure development in China over the period 2013–2020, including well drilling and operation, land rig and fracturing fleet manufacture, and pipeline construction. Multiple scenarios were analyzed based on different combinations of well development rates, well productivities, and success rates. Results suggest that 700–5100 petajoules (PJ) of primary energy will be required for shale gas infrastructure development, while the net primary energy yield of shale gas production over 2013–2020 was estimated at 1650–7150 PJ, suggesting a favorable energy balance. Associated emissions of CO2e were estimated at 80–580 million metric tons, and were primarily attributable to coal-fired electricity generation, fugitive methane, and flaring of methane during shale gas processing and transmission. Direct water consumption was estimated at 20–720 million metric tons. The largest sources of energy use and emissions for infrastructure development were the metals, mining, non-metal mineral products, and power sectors, which should be the focus of energy efficiency initiatives to reduce the impacts of shale gas infrastructure development moving forward.  相似文献   

10.
Summary Biological effects of extremely low-frequency electromagnetic fields (ELF-EMF) on microcirculation were investigated in vivo by monitoring arteriole diameters in conscious mice. Measurements of blood vessel diameter were monitored 33 min non-stop before during and after exposure with ELF-EMF and every 389 ms blood vessel diameter were calculated. Using a dorsal skinfold chamber (DSC), and following caudal vein injection of FITC-dextran 250 kDa, the microvasculature (initial arteriole diameter of 45–80 μm), was examined by intravital microscopy and video images were recorded for a total time of 33 min. Arteriole diameter was continuously measured by on-line analysis using a High-speed Digital Machine Vision System CV-2100, using an edge-gap detection algorithm. Since vessel diameters exhibit rhythmic variation expressed by vasomotion, for estimation of microcirculatory activity we used both raw data for frequency analysis of vasomotion (measured frequencies of vasomotion were in the range 0.008÷0.1 Hz) and evaluate mean blood vessel diameter for each 1 min period of time, and make a comparison between Pre, Exposure/Sham exposure and Post exposure periods, with the aim to evaluate possible changes in mean blood vessel diameter as a result of ELF-EMF action. During EMF exposure and post-exposure periods, arteriole diameters increased significantly compared with the pre-exposure period, and the changes were larger during post-exposure. In contrast to sham exposure, vasodilatation of the microvasculature was significantly greater during exposure and post-exposure to 16 Hz EMF. These findings suggest that ELF-EMF may have potential therapeutic use benefit for treating vascular disorders.  相似文献   

11.
Effects of landfill gas on subtropical woody plants   总被引:2,自引:0,他引:2  
An account is given of the influence of landfill gas on tree growth in the field at Gin Drinkers' Bay (GDB) landfill, Hong Kong, and in the laboratory. Ten species (Acacia confusa, Albizzia lebbek, Aporusa chinensis, Bombax malabaricum, Castanopsis fissa, Liquidambar formosana, Litsea glutinosa, Machilus breviflora, Pinus elliottii, andTristania conferta), belonging to eight families, were transplanted to two sites, one with a high concentration of landfill gas in the cover soil (high-gas site, HGS) and the other with a relatively low concentration of gas (low-gas site, LGS). Apart from the gaseous composition, the general soil properties were similar. A strong negative correlation between tree growth and landfill gas concentration was observed. A laboratory study using the simulated landfill gas to fumigate seedlings of the above species showed that the adventitious root growth ofAporusa chinensis, Bombax malabaricum, Machilus breviflora, andTristania confera was stimulated by the gas, with shallow root systems being induced.Acacia confusa, Albizzia lebbek, andLitsea glutinosa were gas-tolerant, while root growth ofCastanopsis fissa, Liquidambar formosana, andPinus elliottii was inhibited. In most cases, shoot growth was not affected, exceptions beingBombax malabaricum, Liquidambar formosana, andTristania conferta, where stunted growth and/or reduced foliation was observed. A very high CO2 concentration in cover soil limits the depth of the root system. Trees with a shallow root system become very susceptible to water stress. The effects of low O2 concentration in soil are less important than the effects of high CO2 concentration.Acacia confusa, Albizzia lebbek, andTristania conferta are suited for growth on subtropical completed landfills mainly due to their gas tolerance and/or drought tolerance.  相似文献   

12.
Recycling and conservation efforts for water are the need of the day because of the lack of new water sources and the ever-increasing demand for drinking water. Seedlings of Acacia nilotica L. were irrigated with: canal water (T1, control); municipal effluent (T2); textile effluent (T3); steel effluent (T4); textile + municipal effluent in 1:1 ratio (T5); steel + municipal effluent in 1:2 ratio (T6); steel + textile in 1:2 ratio (T8) and steel + municipal + textile in 1:2:2 ratio (T7) with views to observe effluents effect on the seedlings and its adaptability and to recommend safe disposal of these effluents. Seedlings in T6, T7 and T8 showed 50% lesser height and collar diameter than those in control. Seedlings in T2 attained greatest height, collar diameter, numbers of branches and produced 140 g dry biomass seedling−1. Highest concentration of manganese (Mn), iron (Fe), copper (Cu) and zinc (Zn) and lowest concentration of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) in the seedlings of T4, T6, T7 and T8 resulted in nutritional imbalance, mineral toxicity and reduction in photosynthetic (Pn) and transpiration (E) rates and caused seedling mortality. Seedlings of T3 had highest sodium concentration and low concentration of Ca, Mg and micronutrients resulting in nutritional imbalance, augmented chlorosis and reduced gas exchange and biomass by half as compared to control. Increased growth, Pn and E and biomass in seedlings of T5 over T3 and survival period in T6, T7 and T8 seedlings suggested a beneficial effect of effluents mixing. Unscientific disposal should be avoided and toxic concentration of metal ions␣may be reduced for long-term application and harmless disposal of effluents in afforestation and urban development.  相似文献   

13.
Summary The biological effects of electromagnetic radiation at ultra high frequency on human keratinocytes were investigated. HaCaT cell system, a spontaneously immortalized human keratinocytes cell line, was chosen as model since skin is usually exposed to electromagnetic radiation at considered frequency more than inner tissues. HaCaT cells were exposed to a pure sinusoidal field at a frequency of 900 MHz (average SAR levels ranging from 0.04 to 0.08 W/kg) in plane wave condition inside a GTEM chamber for time intervals of 18 hours at a controlled temperature of 37C. Growth curves were obtained for exposed and control cells, and a reduction in the number of exposed cells in comparison to unexposed ones was found; however the number of dead cells was not significantly different in exposed and unexposed samples. In order to investigate whether the reduction in cell proliferation of exposed cells was due to the activation of a differentiative process, the expression of two hallmarks of differentiation was examined. Both keratin 1 and involucrin expression was increased in exposed in comparison to unexposed cells. These results suggest that this protocol of exposure to 900 MHz electromagnetic field can trigger a differentiation program in HaCaT cells.  相似文献   

14.
While the oil industry along the Atlantic coast of Cameroon has made important contributions to the national economy, this has been accompanied with adverse environmental impacts. There has been significant pollution from oil drilling, refinery waste, oil spillage, gas and flaring. After discussing these impacts, this paper argues that prevailing regulations are inadequate and need overhauling. It proposes that cleaner production requires:
(i)
specific laws to protect dwellers in the neighbourhood of oil refineries, filling stations, service stations and pipelines;  相似文献   

15.
Summary In previous publications, we reported that sinusoidal varying magnetic fields (SVMF) modify the activity and dynamics of the malignancy marker adenosine deaminase, and enhance the proliferation of chick embryo fibroblasts (CEF). While the SVMF examined by us (50, 60 & 100 Hz / 0.06–0.7 mT) were all below kT, they may have the potential of altering chemical processes in which excited radicals are involved. We tested this hypothesis in two experimental systems: CEF in culture and Spirodela oligorrhiza (Lemnaceae) (a small aquatic plant, commonly known as Duckweed). CEF were exposed to SVMF of 100 Hz/0.7 mT for 24 h. The addition of the exogenous radical scavengers catalase, superoxide dismutase or vitamin E to the cells during exposure significantly suppressed enhancement of cell proliferation caused by the field (by 79, 67 and 82%, respectively, as evaluated by the MTT colorimetric assay). 15N NMR analysis of Duckweed plants fed by 15N-labeled ammonium chloride and exposed to SVMF at 60 and 100 Hz/0.7 mT for 24 h, revealed augmented alanine production. Alanine did not accumulate in the absence of SVMF. The addition of vitamin C, a radical scavenger, reduced alanine production by 82%. Exposure to SVMF resulted in specific metabolic stress effects in Duckweed plants and enhanced proliferation of CEF. In both cases, it is suggested that free radicals are involved.  相似文献   

16.
Brooks, Bryan W., Susan V. James, Theodore W. Valenti, Jr., Fabiola Urena-Boeck, Carlos Serrano, Jason P. Berninger, Leslie Schwierzke, Laura D. Mydlarz, James P. Grover, and Daniel L. Roelke, 2010. Comparative Toxicity of Prymnesium parvum in Inland Waters. Journal of the American Water Resources Association (JAWRA) 46(1):45-62. DOI: 10.1111/j.1752-1688.2009.00390.x Abstract: Numerous studies have examined the impacts of Prymnesium parvum to aquatic life, but the majority of information available is from experiments or field studies performed at salinities of marine and coastal ecosystems. Ambient toxicity of P. parvum has been characterized with in vitro and in vivo models because reliable quantitation of P. parvum toxins in environmental matrices is often precluded by a lack of available analytical standards. Hemolytic activity and fish mortality assays have been used most frequently to characterize toxic conditions; however, relatively few in vivo studies employed standardized methods. Because the relative sensitivities of different taxa to P. parvum toxins in inland waters were undefined, we assessed the comparative toxicity of P. parvum filtrate from a laboratory study (20°C, 12:12 light:dark cycle, f/8 media, 2.4 psu) to several common standardized in vitro and in vivo models. After exposure to cell-free filtrate hemolytic activity (1 h EC50 = 13,712 cells/ml) and juvenile fish (Pimephales promelas) survival (48 h LC50 = 21,754 cells/ml) were the most sensitive assay responses examined, followed by rotifer (Brachionus calyciflorus) population growth rate [48 h no observable adverse effect levels (NOAEL) = 19,072 cells/ml] and cladoceran (Daphnia magna) reproduction (10-day NOAEL = 47,680 cells/ml). Green algae (Pseudokirchneriella subcapitata) growth (96 h) was not adversely affected but was instead significantly stimulated by P. parvum toxins. We further propose an initial species sensitivity distribution approach for P. parvum, which may be used to support future environmental management decisions. Our findings from these laboratory studies indicate that although fish kills are increasingly associated with P. parvum blooms occurring in inland waters, further study is required to define the influences of toxin sensitivities of phytoplankton, zooplankton, and fish communities on P. parvum bloom initiation and termination.  相似文献   

17.
This study tested the hypotheses that (1) exposure to treated Water Reclamation Plant (WRP) effluent will induce biological effects in exposed fish that are consistent with environmental estrogen (EE) exposure; and (2) seasonal differences in effluent composition will moderate biological effects. We conducted seven on‐site exposures using a mobile laboratory. Total estrogenicity of effluents was 10‐ to 20‐fold higher during spring than in fall. Common EEs including steroid estrogens, alkylphenols, and bisphenol‐A were ubiquitous. An unusual spike in total estrogenicity identified a combined sewer overflow event. Fathead minnows (Pimephales promelas) responded to exposure with subtle changes in vitellogenin concentrations and secondary sex characteristics. An opportunity to assess a common carp (Cyprinus carpio) population permanently sustained inside the Stickney WRP revealed pronounced exposure effects, but also the resilience of biological organisms even under long‐term exposure. In contrast to other studies, no histopathological changes were found. The mobile exposure laboratory proved capable of maintaining U.S. Environmental Protection Agency‐recommended exposure conditions while providing flexibility for rapid deployment at multiple sites with minimal operational disruption. Further studies using this platform hold promise to resolve the convoluted interactions between complex effluents and inherent biological complexity.  相似文献   

18.
ABSTRACT: Fish confined to cages were used to determine the effects of effluent from a wastewater treatment plant (WWTP). Control fish were kept in cages in an aquaculture pond. Acute effects of the effluent entering the final oxidation pond of the WWTP were determined by confining channel catfish (Ictalurus punctatus) at the pond inlet; the mean total residual chlorine (TRC) concentration was 0.9 mg/l during this exposure. After 8 h, 42 percent of the fish had died and survivors had severe lesions of the skin and gills. During the first two weeks of exposure, channel catfish at the outlet of the final oxidation pond (mean TRC=0.1 mg/l) were predisposed to bacterial infection but lost the parasitic trematodes that were on the gills when the fish were placed in cages. After several weeks, exposed fish had histologic lesions, enlarged livers, and reduced growth. The presence of unidentified carcinogen(s) in the effluent of this WWTP was indicated by papillomas developing on caged black bullheads (Ictalurus melas) and hepatic-enzyme induction in channel catfish. In situ exposure of caged fish was advantageous because storage and pretreatment of water samples were not required, and exposure levels corresponded to those present in the environment. The use of cages for containment of fish during field exposure allowed confinement to the location of interest and convenient sampling of the fish. Unlike wild fish, the caged fish could be compared to control fish with the same pre-exposure history.  相似文献   

19.
Responses of lagoon crab, Callinectes amnicola were explored as useful biological markers of heavy metal pollution. The toxicity level of the metals based on the 96-h LC50 values showed that copper with LC50 value of 0.018 mM was found to be two times more toxic than Lead (0.041 mM) against the lagoon crab, C. amnicola. The exposure of the lagoon crab to sublethal concentrations (1/100th and 1/10th of 96-h LC50 values) of Cu and Pb compound, respectively, resulted in the bioaccumulation of the test metals to varying degrees in the selected organs that were dependent on the type of metal and concentration of metal compound in the test media. The degree of metal (Cu and Pb) accumulation was generally in the following order: gills > muscle > heptopancrease. Exposure of the crabs to sublethal concentrations of the metals also caused pathological changes such as the disruption of the gill filaments and degeneration of glandular cells with multifocal areas of calcification in the hepatopancreas. A reduction in the weight of the exposed animals over a 14-day period of observation was also recorded. The significance of these results and the usefulness of the biological endpoints in monitoring programmes aimed at establishing the total environmental level of heavy metals in aquatic ecosystems were discussed.  相似文献   

20.
The objectives of this study were to (1) evaluate the performance of the Multi‐Radar Multi‐Sensor (MRMS) system in capturing precipitation compared to gauge data, and (2) assess the effects of spatial (1–50 km) and temporal (15–120 min) data aggregation scales on the performance of the MRMS system. Point‐to‐grid comparisons were conducted between 215 rain gauges and the MRMS system. The MRMS system at 1 km spatial and 15 min temporal resolutions captured precipitation reasonably well with average R2, root mean square error (RMSE), and percent bias (PBIAS) values of 0.65, 0.5 mm, and 11.9 mm; whereas Threat Score, probability of detection, and false alarm ratio were 0.57, 0.92, and 0.40, respectively. Decreasing temporal resolution from 15 min to two hours resulted in an increase in R2 and a decrease in RMSE, whereas PBIAS was not affected. Reducing spatial resolution from 1 to 50 km resulted in increases in R2 and PBIAS, whereas RMSE was decreased. Increasing spatial aggregation scale from 1 to 50 km resulted in an R2 increase of only 0.08. Similarly, improvement in R2 was only modest (0.17) compared to an eightfold reduction in temporal resolution (from 15 min to two hours). While aggregating data at coarser temporal resolutions resolved some of the under/overestimation issues of the MRMS system, it was apparent even at coarser spatial and temporal resolutions the MRMS system inherently overestimated smaller precipitation events while underestimated bigger events.  相似文献   

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