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1.
We have previously found great differences in susceptibility to methylmercury (meHg) among batches of eggs produced by different females. This study compares the range and distribution of susceptibility in two populations of killifish, one from a creek in Montauk, New York, USA a rather pristine area, the other from Pile's Creek in Linden, New Jersey, an area heavily impacted by metal and oil pollution. After treatment with 0.05 ppm meHg, the distribution of craniofacial defects in embryos of the Montauk population ranged from very tolerant to very susceptible. The distribution of cardiovascular defects also ranged from very tolerant to very susceptible. Skeletal defects were prevalent in most batches of eggs. However, in the Pile's Creek population, very few females produced susceptible eggs, and most batches were tolerant with respect to the three types of malformations, especially the craniofacial defects. The ability to adapt to pollution is one reason that this species has remained abundant in such a highly polluted area. The ability of some species to adapt to chronic pollution by developing tolerance is a phenomenon that should be considered in choosing organisms for routine bioassay procedures, since the results will depend on the degree to which the population has become tolerant to the toxicant.  相似文献   

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The purpose of this work is to relate the results and the conclusions which arose from the operation of nuclear plants from many years and from the application various radioecological models which describe the diffusing and the burdening of ecological system with radioactive substances in relation to the general problem of the pollution of the environment with whatever type of radioactive filthiness.

It is believed that the findings resulting from such comparison will be very interesting and will contribute to the taking of the right measures to face the pollution of the environment. This study is very important for countries such as Greece which has no nuclear plants but has a rapidly developed industry. The research has been mainly concentrated to the industrial area of Thessaloniki (Sindos) which is considered as the main source of diffused filthiness and which in the last few years has caused serious problems of pollution to the wider area of Thessaloniki.  相似文献   

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Relatively low concentrations of fluorine in drinking water ( 1 mg F/l) have been shown to significantly reduce the degree of dental caries in children and fluorine would also appear to have a beneficial effect on bone formation in both humans and farm animals. However, it is apparent that elevated levels of fluorine in the diet have sometimes resulted in problems of increased dental caries and of the development of bone deformities. Much of the fluorine in rocks and soils occurs in apatite and hydroxysilicate minerals, fluorite being the only relatively common rock forming mineral containing fluorine as an essential constituent.Little systematic data are available on fluorine concentrations in soils, plants and natural waters in the UK. General background soil concentrations lie in the range 200 – 400 mg F/kg. For waters the average fluorine content is low, <0.1 mg F/l.In the British Isles there are several areas where there are enhanced levels of fluorine. In the northern Pennines, Derbyshire, northeast Wales and Cornwall, fluorite occurs as a significant component of mineralisation and much fluorine has been added to the environment from mining waste dumps. Soils in northeast Wales contain up to 3,650 mg F/kg and in the northern Pennines up to 20,000 mg F/kg. Waters contain up to 2.3 mg F/l. In southwest England, the granites are generally fluorine-rich with the fluorite granites of the St Austell pluton containing as much as 1 percent fluorine. These rocks are frequently kaolinised and intensively worked as a source of china clay. Soils in the vicinity of the waste tips contain up to 3,300 mg F/kg and grasses up to 2,950 mg F/kg. Surface waters in the St Austell area contain up to 1.25 mg F/l.Atmospheric fluorine pollution around brickworks in the Peterborough and Bedford areas has resulted in fluorosis in farm animals. Other sources of atmospheric fluorine pollution are aluminium smelters, steelworks and fossil fuel burning.  相似文献   

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Many pharmaceutical pollutants are chiral, existing in the environment as a single enantiomer or as mixtures of the two enantiomers. In spite of their similar physical and chemical properties, the different spatial configurations lead the enantiomers to have different interactions with enzymes, receptors or other chiral molecules, which can give diverse biological response. Consequently, biodegradation process and ecotoxicity tend to be enantioselective. Despite numerous ongoing research regarding analysis and monitorization of pharmaceutical ingredients in the environment, the fate and effects of single enantiomers of chiral pharmaceuticals (CP) in the environment are still largely unknown. There are only few chiral analytical methods to accurately measure the enantiomeric fraction (EF) in environmental matrices and during biodegradation processes. Furthermore, the ecotoxicity studies usually consider the enantiomeric pair as unique compound. We reviewed the current knowledge about CP in the environment, as well as the chiral analytical methods to determine the EF in environmental matrices. The degradation and removal processes of CP of important therapeutic classes, usually detected in the environment, and their toxicity to aquatic organisms were also reviewed. On the other hand, this review demonstrate that despite the great importance of the stereochemistry in pharmaceutical science, pharmacology and organic chemistry, this is normally neglected in environmental studies. Therefore, CP in the environment need much more attention from the scientific community, and more research within this subject is required.  相似文献   

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There is a growing recognition that individual exposures to a broad spectrum of metal, inorganic and organic pollutants exceed those from ambient and in some cases from the vicinity of industry environments. The agents often found in indoor environments are mostly known to be hazardous in high concentrations, but the lower limit of their dose response relationships are poorly defined.

The major sources of metals in indoor environments are cigarette smoke (mainstream and side stream), fuel combustion, house dust and consumer products with arsenic, cadmium, lead and nickel being of primary toxicological potential (i.e. carcinogenic, genotoxic and reproductive development). Aspects of levels and duration of human exposure to these elements in relation to existing body burdens and subsequent bioavailability and interactions are generally poorly known from inhalation sources.

Although the magnitude of indoor health hazards to metallic constituents is not now known, mounting evidence suggests that both identification of agents and the measurement of indoor exposures are critical for a more realistic assessment of the effect of this aspect of air pollution on human health.  相似文献   

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This paper reviews literature on the sources of lead-zinc mining pollution, and specifically deals with the water and air pollution aspects of these operations. Problems associated with mining and the environment are also discussed. The problems are geochemical in nature but also economic, social, political and legal. Individuals doing research in these boundary conditions are poorly publicised and rarely recognised outside of their own narrow industry.The paper notes that it is possible to have both an economical mining operation and a clean environment. The New Lead Belt region of Southern Missouri, the world's largest lead-mining region lies underneath a national forest with a pure, pristine, undisturbed ecosystem having high recreational value to the nearby cities. By early cooperation between governmental scientists, mining industry, environmental scientists and engineers of the University of Missouri and other universities it was possible to develop this deposit and at the same time keep the pristine nature of the surrounding forest without spending a single day in court or litigation. Problems did arise, but problem-solving sessions dealt with them, not lawyers.  相似文献   

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绿色化学研究与生态环境保护   总被引:2,自引:0,他引:2  
赵文岩  戴树桂  韩萌 《生态环境》2004,13(3):425-428
绿色化学是指利用一系列原理来降低或消除在化工产品的设计、生产及应用中有害物质的使用和产生的科学。它致力于从源头上制止污染物的生成。文章从非传统的绿色原材料、溶剂、试剂、催化剂、安全化学品及合成方法方面综述了绿色化学的研究进展。绿色化学从材料和能源的内在性质上面对生态环境问题的挑战,在分子水平上设计结构及其相关的性质,通过减少内在的危害而使生态系统的发展具有可持续性。发展绿色化学是实现生态环境保护的途径。  相似文献   

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This study investigates the impact of building aspect ratio (building-height-to-street-canyon-width-ratio), wind speed and surface and air-temperature difference (Δθs−a) on the heating environment within street canyon. The Reynolds-averaged Navier-Stokes (RANS) and energy transport equations were solved with Renormalization group (RNG) theory version of k-e{\varepsilon} turbulence model. The validation process demonstrated that the model could be trusted for simulating air-temperature and velocity trends. The temperature and velocity patterns were discussed in idealized street canyons of different aspect ratios (0.5–2.0) with varying ambient wind speeds (0.5–1.5 m/s) and Δθs−a (2–8 K). Results show that air-temperatures are directly proportional to bulk Richardson number (R b ) for all but ground heating situation. Conversely, air-temperatures increase significantly across the street canyon with a decrease in ambient wind speed; however, the impact of Δθs−a was negligible. Clearly, ambient wind speed decreases significantly as it passes over higher AR street canyons. Notably, air-temperatures were the highest when the windward wall was heated and the least during ground heating. Conversely, air-temperatures were lower along the windward side but higher within the street canyon when the windward wall was heated.  相似文献   

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Mediterranean octocorallian communities and the abiotic environment   总被引:1,自引:0,他引:1  
Octocorallian communities (Coelenterata: Anthozoa) were investigated in 40 underwater stations near Banyuls-sur-Mer (France), as representatives of Mediterranean benthic fauna. The stations, with depths ranging from 0.3 to 40 m, were all sampled by means of SCUBA-diving. Along with a faunistic inventory, the main abiotic properties of each station were examined, such as irradiance, temperature, water movement, slope and presence of sediment. By means of cluster analysis and factor analysis, the main properties of which are briefly outlined in this paper, the existence of 5 separate communities is demonstrated. Two major abiotic factors emerge from this study, viz. submarine daylight and the presence or absence of sediment. Although community structures are found to be correlated with the physical environment, no causal relationships have been established. It is suggested that the tolerance of larval and young adult stages play an important role in this respect.  相似文献   

13.
The chemistry of aluminum in the environment   总被引:6,自引:0,他引:6  
There is increased concern over the effects of elevated concentrations of Al in the environment. Unfortunately, studies of the environmental chemistry and toxicity of Al have been limited by our understanding of the processes regulating the aqueous concentration, speciation and bioavailability of this element.Although Al is the most abundant metallic element in the Earth's crust, it is highly insoluble and generally unavailable to participate in biogeochemical reactions. However, under highly acidic or alkaline conditions, or in the presence of complexing ligands, elevated concentrations may be mobilized to the aquatic environment. Ecologically significant concentrations of Al have been reported in surface waters draining acid-sensitive regions that are receiving elevated inputs of acidic deposition. Acid- sensitive watersheds are characterized by limited release of basic cations (Ca2+, Mg2+, Na+, K+) and/or retention of strong acid anions (SO4 2–, NO3 , Cl). Under these conditions inputs of strong acids are not completely neutralized, but rather acidic water is exported from the terrestrial environment. It has been hypothesized that acidic deposition to acid-sensitive watersheds mobilizes Al within the mineral soil, causing elevated concentrations in soil solutions and surface waters. As a result of mineral phase solubility constraints, concentrations of aqueous Al increase exponentially with decreases in pH below 6.0.Monomeric Al occurs as a series of complexes in the aqueous environment, including aquo, OH, F, SO4 2–, HCO3 and organic species. Of these aquo, OH, F and organic complexes are the most significant in natural waters.Elevated concentrations of Al are ecologically significant because: 1) Al is an important pH buffer in acidic waters, regulating the lower limit of pH values following acidification by strong acids; 2) through adsorption and coagulation reactions, Al may alter the cycling and availability of important elements like phosphorus, organic carbon and certain trace metals; 3) Al may serve as a coagulant facilitating the removal of light attenuating materials, thereby increasing the clarity and decreasing the thermal stability of lakes; and 4) Al is potentially toxic to organisms. Better understanding of the chemistry and speciation of Al is essential to assess these effects.  相似文献   

14.
The marine environment is being increasingly exploited by fisheries and the oil and gas industry. Conservationists urgently need the ability to identify the processes that determine patterns of abundance of marine species. We describe a preliminary Geographic Information System (GIS) in which spatial data on environmental variables (seabird colony locations, sea depth and seabed sediments) are integrated with realistic energy constraints faced by marine birds during the breeding season. A simple foraging model predicts the spatial variation in the quality of given locations as potential feeding sites under different feeding conditions and stages of the breeding cycle. We show how the approach can be used to help managers identify key marine areas and assess the impacts of environmental change or damage.  相似文献   

15.
We examine the choice of policy instruments (price, quantity or a mix of the two) when two pollutants are regulated and firms' abatement costs are private information. Whether abatement efforts are complements or substitutes is key determining the choice of policies. When pollutants are complements, a mixed policy instrument with a tax on one pollutant and a quota on another is sometimes preferable even if the pollutants are identical in terms of benefits and costs of abatement. Yet, if they are substitutes, the mixed policy is dominated by taxes or quotas.  相似文献   

16.
This paper considers the environmental problems which might face the state of Western Australia in the next two decades, against the background of a development scenario, current concern over the environment, and the Doomsday Syndrome which seems to be conditioning much of current thinking. Two important aspects of the State's future are considered: resource depletion and pollution. A positive view of the resource depletion problem is taken in that it is impossible to assess reserves of natural resources without considering the impact of science and technology upon resource development and discovering new resources. There is also considerable evidence of success in combating pollution within the present system.It is a difficult task, particularly for the layman, to decide just what to believe in the face of the great and growing volume of errors of fact which find their way into the media on environmental matters. The result of this seems to be that an adversary approach has been adopted in environmental stances, and development tends to be halted whilst debates are carried on.The current status of environmental science is reviewed and leads to the proposition that growth and environmental quality can be compatible if new philosophies of growth and resource management are developed based on conservation and progress. The major difficulties are not seen as the predictions of doom but Western society's growing incapacity for action and an unwillingness toassume control of its own destiny.Based on a paper presented to Prospect 2000-A Conference on the Future, Australia and New Zealand Association for the Advancement of Science, Perth, Western Australia, 14–18 May, 1979.  相似文献   

17.
Enforcement of policy is typically delegated. What sort of mission should the head of an enforcement program be given? When there is more than one firm being regulated the firms’ decision problems—otherwise completely separate—become linked in a way that depends on that mission. Under some sorts of missions firms compete to avoid the attention of the enforcer by competitive reductions in the extent of their non-compliance, in others the interaction encourages competitive expansions. We develop a general model that allows for the ordering of some typical classes of missions. We find that in plausible settings ‘target-driven’ missions (that set a hard target in terms of environmental outcome but flexible budget) achieve the same outcome at lower cost than ‘budget-driven’ ones (that fix the enforcement budget). Inspection of some fixed fraction of firms is never optimal.  相似文献   

18.
Tetracycline antibiotics in the environment: a review   总被引:4,自引:0,他引:4  
Tetracycline antibiotics are one of the primarily antibiotics groups used for veterinary purposes, for human therapy and for agricultural purposes. Amongst the different antibiotics used, more attention is paid to tetracycline’s as it exhibits serious environmental problems including ecological risks and human health damages. Due to their extensive usage, most of the actual evidence suggests that tetracycline antibiotics are omnipresent compounds found in different ecological compartments. After medication, more than 70 % of tetracycline antibiotics are excreted and released in active form into the environment via urine and feces from humans and animals. Their highly hydrophilic character and low volatility have resulted in significant persistence in the aquatic environment. Very few studies describe the fate and toxicity of tetracycline antibiotics in the environment. Here, we review several important issues with regard to: (1) the toxicity of these compounds on aquatic and terrestrial organisms; (2) their estrogenic effects; (3) their behavior in different ecological systems and; (4) the by-products generated during water treatment. These antibiotics residues promote the development of antibiotic resistant microorganisms, which can induce adverse effect to human health by increasing the risk of certain infections. Based on recent research results, the occurrence of tetracycline antibiotics in the environment inhibits the growth of some terrestrial and aquatic species. Besides, the residual concentrations of such drugs could affect steroidogenic pathway and consequently may cause endocrine disruption of aquatic species. Most of the wastewater treatment plants are not capable of removing effectively the tetracycline antibiotics. Therefore, there is a need to develop alternative processes to remove them from waters. Advanced oxidation processes have been proposed as alternative methods to ensure higher degradation and mineralization of tetracycline antibiotics are present in waters.  相似文献   

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Trachurus capensis is an important fisheries resource in the degraded Namibian upwelling ecosystem. Food supply and shoaling of hypoxic zones are hypothesised to influence the species’ recruitment success. This paper is the first to quantify energy requirements and hypoxia tolerance of larval and juvenile stages of a Trachurus species. We measured normoxic respiration rates of T. capensis with a size range from 0.001 to 20.8 g wet mass (WM) collected off Cape Town (33.9°S, 18.5°E, 12/2009) and in the northern Benguela (17–24°S, 11–15°E, 02/2011). Routine metabolic rate (RMR) and standard routine rate (SRR) (mg O2 h?1) followed the allometric functions RMR = 0.418 WM0.774 and SRR = 0.275 WM0.855, respectively. Larvae and juveniles had comparatively high metabolic rates, and the energy demand of juveniles at the upper end of the size range appeared too high to be fuelled by a copepod diet alone. T. capensis’ early life stages showed a high tolerance to hypoxic conditions. RMR in larvae did not change until 30 % O2sat at 18 °C. In juveniles, critical oxygen saturation levels were low (PC for SRR = 11.2 ± 1.7 % O2sat and PC for RMR = 13.2 ± 1.6 % O2sat at 20 °C) and oxy-regulation effective (regulation index = 0.78 ± 0.09). A high hypoxia tolerance may facilitate the retention of larvae in near-shore waters providing favourable feeding conditions and allowing juveniles to exploit food resources in the oxygen minimum zone. These mechanisms seem to well adapt T. capensis to a habitat affected by spreading hypoxic zones and probably enhance its recruitment success.  相似文献   

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