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1.
Specimens of oceanic decapods, mysids and euphausiids, collected from the North East Atlantic Ocean during July 1985, were analysed for V, Cr, Mn, Fe, Ni, Co, Cu, Zn, As and Cd. Measurement of the metals was carried out using two techniques: inductively-coupled plasma-source mass spectrometry (ICP-MS) and atomic absorption (AAS). With the exception of the iron data, good agreement was observed between the data from the two techniques. Baseline-metal data are presented for the species measured, along with any effects of animal size on metal concentration. The data presented for oceanic animals from different trophic levels are important in studies of metal fluxes and for the assessment of markers within the food web in the oceans.  相似文献   

2.
For the transition metals chromium, nickel, iron, copper, cobalt, platinum, and molybdenum, mechanisms of stable bonding in biochemistry (emphasis on carcinogenic mechanisms), chemistry, industrial chemistry, as well as epidemiological, occupational, orthopedic (implant devices) effects related to carcinogenesis, were reviewed. Hypothetically, the propensity to stable bonding (inertness), which ensures the metals’ performance capacity for consumers and industrial application, relates to their carcinogenicity. For chromium, a relationship between industrial/chemical and biological reactivity was noted for the tendency of Cr(III) ions to cause hydrolysis previous to stable bonding, as occurs during anodic passivation, leather tanning, and as indicated in biochemical studies pertaining to a mechanism of DNA condensation, which was suggested as a carcinogenic mechanism. The involvement of metal hydrolysis in both anodic passivation and biochemistry was noted also for nickel, iron, and platinum; the DNA interaction of platinum (cis-platin) is known to depend on hydrolysis. For nickel, issues of potential (V) were found important in both passivation and carcinogenicity. Comparably, the passivity behavior of cobalt and copper was found atypical, and their carcinogenicity yet unclear. Molybdenum, contained in passivated metallic implants, may relate to implant-associated carcinogenesis. Occupational carcinogenic effects were indicated for chromium, nickel, iron, and cobalt as caused by both reactive and passivated metal species. Exposure to acids and chronic respiratory irritation/infection/inflammation in workers were important cofactors in metal carcinogenesis. For wood and leather workers exposed to dust, the assumed presence in dust of metal particles abraded from alloys (sawing or cutting blades) may be a carcinogenic exposure hazard.  相似文献   

3.
A sequential extraction technique was applied to estimate the chemical association of Mn, Zn, Cu and Pb in five chemical phases (exchangeable, carbonate, Fe–Mn oxides, organic matter and residual) in sediments of the Gulf of Aden, Yemen. The results indicated that a higher level of Mn was associated with the residual fraction (natural sources) than the non-residual fraction (anthropogenic sources). Zn fractionations revealed that it was associated more with Fe–Mn oxides and organic fractions than exchangeable and carbonate fractions. Most of the Cu was present in the residual form (60–72%) except for in the main port area (zone III), where it was associated with the organic phase (77% of the total Cu content, the organic matter content was 5%). Similarly, most Pb was bound in the residual fraction (56–71%) except the main port area where ~ 62% of the total Pb was bound in non-residual fractions. It was also found that the Pb concentration in the exchangeable fraction was very high compared with other metals. The risk assessment code for the metals showed a low risk for Zn and Cu, but low to medium risk for Mn. Fractionation of Pb showed medium risk at most of the regions except at the eastern area, which revealed a high risk for the aquatic environment.  相似文献   

4.
The design of marine reserves is complex and fraught with uncertainty. However, protection of critical habitat is of paramount importance for reserve design. We present a case study as an example of a reserve design based on fine-scale habitats, the affinities of exploited species to these habitats, adult mobility, and the physical forcing affecting the dynamics of the habitats. These factors and their interaction are integrated in an algorithm that determines the optimal size and location of a marine reserve for a set of 20 exploited species within five different habitats inside a large kelp forest in southern California. The result is a reserve that encompasses approximately 42% of the kelp forest. Our approach differs fundamentally from many other marine reserve siting methods in which goals of area, diversity, or biomass are targeted a priori. Rather, our method was developed to determine how large a reserve must be within a specific area to protect a self-sustaining assemblage of exploited species. The algorithm is applicable across different ecosystems, spatial scales, and for any number of species. The result is a reserve in which habitat value is optimized for a predetermined set of exploited species against the area left open to exploitation. The importance of fine-scale habitat definitions for the exploited species off La Jolla is exemplified by the spatial pattern of habitats and the stability of these habitats within the kelp forest, both of which appear to be determined by ocean microclimate.  相似文献   

5.
Environmental Chemistry Letters - Effective technologies and materials are needed for environmental detoxification and clean energy production. The actual photocatalytic technology is largely...  相似文献   

6.

The development and recycling of biomass production can partly solve issues of energy, climate change, population growth, food and feed shortages, and environmental pollution. For instance, the use of seaweeds as feedstocks can reduce our reliance on fossil fuel resources, ensure the synthesis of cost-effective and eco-friendly products and biofuels, and develop sustainable biorefinery processes. Nonetheless, seaweeds use in several biorefineries is still in the infancy stage compared to terrestrial plants-based lignocellulosic biomass. Therefore, here we review seaweed biorefineries with focus on seaweed production, economical benefits, and seaweed use as feedstock for anaerobic digestion, biochar, bioplastics, crop health, food, livestock feed, pharmaceuticals and cosmetics. Globally, seaweeds could sequester between 61 and 268 megatonnes of carbon per year, with an average of 173 megatonnes. Nearly 90% of carbon is sequestered by exporting biomass to deep water, while the remaining 10% is buried in coastal sediments. 500 gigatonnes of seaweeds could replace nearly 40% of the current soy protein production. Seaweeds contain valuable bioactive molecules that could be applied as antimicrobial, antioxidant, antiviral, antifungal, anticancer, contraceptive, anti-inflammatory, anti-coagulants, and in other cosmetics and skincare products.

  相似文献   

7.
Decades of intensive industrial and agricultural practices as well as rapid urbanization have left communities like Pueblo, Colorado facing potential health threats from pollution of its soils, air, water and food supply. To address such concerns about environmental contamination, we conducted an urban geochemical study of the city of Pueblo to offer insights into the potential chemical hazards in soil and inform priorities for future health studies and population interventions aimed at reducing exposures to inorganic substances. The current study characterizes the environmental landscape of Pueblo in terms of heavy metals, and relates this to population distributions. Soil was sampled within the city along transects and analyzed for arsenic (As), cadmium (Cd), mercury (Hg) and lead (Pb). We also profiled Pueblo’s communities in terms of their socioeconomic status and demographics. ArcGIS 9.0 was used to perform exploratory spatial data analysis and generate community profiles and prediction maps. The topsoil in Pueblo contains more As, Cd, Hg and Pb than national soil averages, although average Hg content in Pueblo was within reported baseline ranges. The highest levels of As concentrations ranged between 56.6 and 66.5 ppm. Lead concentrations exceeded 300 ppm in several of Pueblo’s residential communities. Elevated levels of lead are concentrated in low-income Hispanic and African-American communities. Areas of excessively high Cd concentration exist around Pueblo, including low income and minority communities, raising additional health and environmental justice concerns. Although the distribution patterns vary by element and may reflect both industrial and non-industrial sources, the study confirms that there is environmental contamination around Pueblo and underscores the need for a comprehensive public health approach to address environmental threats in urban communities.  相似文献   

8.
This article derives Pigouvian-type corrective measures for reciprocal externalities when non-Nash behavior characterizes the participants. These reciprocal externalities may involve various kinds of environmental pollutants, such as acid rain. A comparison between corrective measures for Nash and non-Nash behavior demonstrates that positive conjectures, regarding the other agent's externality-generating activity, have an expectation-internalizing influence that usually reduces the required corrective measures. Negative conjectures (e.g., free-riding expectations), however, have an expectation-externalizing effect that increases the required corrective measures. The article analyzes both two-person and n-person externalities.  相似文献   

9.
Abstract

Due to vast research programmes of industrial countries during the last two decades, our knowledge about the intrinsic properties of nanomaterials has increased considerably. However, ‘nanoregulation’ lags behind this progress. Key elements of nanoregulation are definition/scope and safety/consumer information. Safety information along the nano life-cycle is vital for the nanoparticle producer down to the industrial downstream user (product producer). However, nanodeclaration (in the sense of a label on the product for consumers) is not yet widely spread, in different geographic regions for different reasons. This is a case study for the EU, Switzerland, Thailand, the USA, and Intergovernmental Organisations. In addition, this study investigates inter- and governmental activities and the relationship between nanodeclaration and WTO rules. Non-compliance with WTO rules is a pretext for not introducing nanodeclaration in products. It is concluded that WTO rules do not exclude nanodeclaration.  相似文献   

10.
Residues of PCDDs/F, non-ortho, mono-ortho PCBs, and other PCBs were monitored in the tissues of mullet fish, bolti fish, bivalves and crab taken from Lake Temsah, at Ismailia, Egypt.

Results showed that 2,3,7,8 Tetra CDD and 1,2,3,7,8 Penta CDD were the most frequently detected PCDD congeners. Similarly, 2,3,7,8 Tetra CDF, 1,2,3,7,8 Penta CDF and 2,3,4,7,8 Penta CDF were the most frequently detected PCDF congeners. No relationship was apparent between the concentrations of detected PCDDs congeners and the degree of chlorination, except with crab samples in which an increase in the chlorination coincided with a decrease in the concentrations of the congeners.

In PCDF congeners, detected residues have had a reversed relationship with chlorination increase. In PCDD congeners, Octa CDD had the highest detected concentrations in the two fish species, while in the bivalves and crab, 2,3,7,8 Tetra CDD had the highest concentrations. The mullet fish had the highest total PCDDs concentration, at 0.398?pg/g fresh weight, followed by crab at 0.395?pg/g fresh weight, then bivalves and bolti fish at 0.187 and 0.062?pg/g fresh weight, respectively. In all the examined organisms, the total concentrations of PCDFs were much higher than the total concentrations of the PCDD congeners. The WHO–TEQ values were 11.92, 39.12, 25, and 3.6?pg/g fresh weight, for mullet fish, bolti fish, bivlaves and crab, respectively. The concentration of the mono-ortho congeners CB 118 was the highest detected of all non-ortho and mono-ortho PCBs congeners, with values of 0.382, 0.022, 0.231 and 0.357?ng/g fresh weight, in mullet fish, bolti fish, bivalves and crab, respectively. The WHO–TEQ concentrations were 0.799, 0.003?pg/g fw, 0.05?pg/g fresh weight, 0.676?pg/g, and 0.799?pg/g fresh weight, for the same species, respectively. The total concentration of PCBs 28, 52, 95, 99, 101, 105, 110, 118, 138, 146, 149, 151, 153, 170, 177, 180, 187 were 6.86?ng/g fresh weight for mullet fish, 0.2?ng/g fresh weight, for bolti fish, 2.72?ng/g fresh weight for bivalves and 2.8?ng/g fresh weight for crab, respectively.  相似文献   

11.
Feeding rates, conversion efficiencies and growth of larvae of the mummichog Fundulus heteroclitus, an extremely abundant estuarine fish, were measured at temperatures ranging from 18° to 30°C. The food used was Artemia salina nauplii. At the time of total yolk sac absorption (5 to 7 days after hatching), the feeding rate decreased for a short time, an indication of a shift in metabolism. Higher feeding rates and growth occurred at higher rearing temperatures. The highest conversion efficiency (gross growth efficiency) was 1.1%, at 22°C. Mummichog larvae may be energetically inefficient compared with other fish species, but efficiency might not be critical for this fish, which is an opportunistic omnivore in an energy-rich environment.Contribution No. 291 of the Belle W. Baruch Institute for Marine Biology and Coastal Research, supported by DOE contract No. EY-76-5-09-0869.  相似文献   

12.
This paper estimates the impact of climate change on the prevalence of criminal activity in the United States. The analysis is based on a 30-year panel of monthly crime and weather data for 2997 US counties. I identify the effect of weather on monthly crime by using a semi-parametric bin estimator and controlling for state-by-month and county-by-year fixed effects. The results show that temperature has a strong positive effect on criminal behavior, with little evidence of lagged impacts. Between 2010 and 2099, climate change will cause an additional 22,000 murders, 180,000 cases of rape, 1.2 million aggravated assaults, 2.3 million simple assaults, 260,000 robberies, 1.3 million burglaries, 2.2 million cases of larceny, and 580,000 cases of vehicle theft in the United States.  相似文献   

13.
Heavy metals pollution in aquatic environments is a major problem contributing to human health issues. The study of these pollutants through bioindicators such as the oyster Crassostrea iredalei is important for (1) determining the levels and sources and (2) regulating the quantity of pollutants. The concentrations of cadmium (Cd), manganese (Mn), copper (Cu), zinc (Zn), and lead (Pb) in tissues of C. iredalei, sediment and surrounding water was measured, and data was analyzed to determine the relationship between sampling periods and between oyster tissue, sediment, and water. The highest concentration of metals in oyster tissue was Zn, followed by Cu, Mn, Cd, and Pb. Concentrations of Cd, Cu, and Zn exceeded the maximum level allowed according to the Malaysian Food Act of 1983, which is equivalent to the WHO recommended levels of heavy metals in organisms used for consumption. The highest metal concentration in sediment was Mn followed by Zn, Pb, Cu, and Cd. Concentrations of heavy metals in surrounding water were Zn, Pb, Cu, Mn, and Cd. There was no correlation between metal concentration in oyster tissue and in sediment for all five metals.  相似文献   

14.
Abstract: Although economic analysis can be used to argue for preservation of species and habitats, many natural assets represent inferior investments in society's asset portfolio. We demonstrate this for the case of ancient temperate rainforests and minke whales (  Balaenoptera acutorostrata ). For both rainforests and whales, we determined their value for harvest and balanced this against society's valuation of the preserved stock. For the market and nonmarket data available, we then determined how much rainforest and how many minke whales global society should keep in its asset portfolio. Although ecologists increasingly attempt to justify preservation of biological assets on economic grounds, we argue that this might be a dangerous approach to take. Ultimately, it may be necessary to reexamine the ethical foundations for conservation of nature and biodiversity, including the economist's use of utilitarianism. We suggest that the safe minimum standard approach may prove useful in practice.  相似文献   

15.
Sulfide-bearing mill wastes are sources of high concentrations of acid, soluble metals, Sb, and As. Contents of Cu, Zn, Fe, Pb, Cd, As, and Sb in wastes of the Belovo Zn-processing and the Karabash mineral-processing plants (Russia) exceed the average content in the upper continental crust and background soils. High-dissolved metal and As concentrations are found in acid drainages, which form as a result of interaction between sulfide wastes and water. Monitoring research using geochemical and geophysical methods was performed to evaluate the contamination of the surrounding area (water and bottom sediments in the contaminated rivers and snow cover). Zones of geochemical anomalies were identified where the concentrations of Fe, Cu, Zn, Cd, Pb, and As are 2–3 orders of magnitude higher than in drinking water standards (for rivers) and background levels (for snow). The use of geophysical methods allowed us to prove penetration of drainage solutions into the groundwaters. The total environmental damage caused by the pollution of water and land resources in the Belovo Zn-processing plant waste disposal area amounted to $156 million at the time of 2011, and could reach $480 million by 2030, if steps are not taken in recycling and remediation of disturbed areas.  相似文献   

16.
Wildlife management is limited by uncontrolled and often unrecognized environmental variation, by limited capabilities to observe and control animal populations, and by a lack of understanding about the biological processes driving population dynamics. In this paper I describe a comprehensive framework for management that includes multiple models and likelihood values to account for structural uncertainty, along with stochastic factors to account for environmental variation, random sampling, and partial controllability. Adaptive optimization is developed in terms of the optimal control of incompletely understood populations, with the expected value of perfect information measuring the potential for improving control through learning. The framework for optimal adaptive control is generalized by including partial observability and non-adaptive, sample-based updating of model likelihoods. Passive adaptive management is derived as a special case of constrained adaptive optimization, representing a potentially efficient suboptimal alternative that nonetheless accounts for structural uncertainty.  相似文献   

17.
邢军 《生态环境》2011,20(11):1720-1724
以斑马鱼(Zebra fish)Danio rerio、剑尾鱼Xiphophorus hellerii、孔雀鱼(Guppy)Poecilia reticulata为受试鱼种,采用半静态试验,考察苯、苯酚、氯苯、4-氯苯酚对3种鱼的急性毒性,结果表明,上述4种有机物对斑马鱼的96 h LC50分别为132.22、28.86、9.66、4.29 mg.L-1;对剑尾鱼的96 h LC50分别为123.76、27.25、8.86、4.29 mg.L-1;对孔雀鱼的96 h LC50分别为131.25、27.88、9.33、4.59 mg.L-1,都属于高毒物质。毒性大小为苯〈苯酚〈氯苯〈4-氯苯酚。毒性大小与取代基的类型有关,-Cl的毒性要大于-OH,-Cl和-OH的联合毒性大于单独的-Cl和-OH。孔雀鱼和剑尾鱼对上述有机污染物具有较好的敏感性,结果稳定,重现性好,可以作为急性毒性试验的受试鱼种。  相似文献   

18.
This paper describes the quantitative determination of F, Cl, Br, Cd and Pb in plastic materials. The concentration of the elements Cl, Br, Cd and Pb is first semiquantitatively measured by X‐ray fluorescence spectrometry (XRF) directly in the solid sample with a detection limit of approximately 10 μg/g. Afterwards, F and any of the other elements which exceed the limit values for materials which are disposable without special precautions are measured after the digestion of the material. The samples are digested either under pressure in an oxygen atmosphere for F, Cl and Br or under pressure with nitric acid for Cd and Pb. The digestion converts the halides to the anions which are measured potentiometrically (F, Br) or with ion chromatography (Cl). Cd and Pb are measured by graphite furnace atomic absorption spectrometry (GF‐AAS). The determination limits achieved are 20 μg/g for F and Br, 250 μg/g for Cl, 0.01 μg/g for Cd and 0.2 μg/g for Pb, all below the limit values set by current regulations in Switzerland.  相似文献   

19.
Extinctions typically have ecological drivers, such as habitat loss. However, extinction events are also influenced by policy and management settings that may be antithetical to biodiversity conservation, inadequate to prevent extinction, insufficiently resourced, or poorly implemented. Three endemic Australian vertebrate species—the Christmas Island pipistrelle (Pipistrellus murrayi), Bramble Cay melomys (Melomys rubicola), and Christmas Island forest skink (Emoia nativitatis)—became extinct from 2009 to 2014. All 3 extinctions were predictable and probably preventable. We sought to identify the policy, management, research, and other shortcomings that contributed to their extinctions or failed to prevent them. These included a lack within national environmental legislation and policy of explicit commitment to the prevention of avoidable extinctions, lack of explicit accountability, inadequate resources for conservation (particularly for species not considered charismatic or not of high taxonomic distinctiveness), inadequate biosecurity, a slow and inadequate process for listing species as threatened, recovery planning that failed to consider the need for emergency response, inability of researchers to identify major threatening factors, lack of public engagement and involvement in conservation decisions, and limited advocacy. From these 3 cases, we recommend: environmental policy explicitly seeks to prevent extinction of any species and provides a clear chain of accountability and an explicit requirement for public inquiry following any extinction; implementation of a timely and comprehensive process for listing species as threatened and for recovery planning; reservation alone not be assumed sufficient to maintain species; enhancement of biosecurity measures; allocation of sufficient resources to undertake actions necessary to prevent extinction; monitoring be considered a pivotal component of the conservation response; research provides timely identification of factors responsible for decline and of the risk of extinction; effective dissemination of research results; advocacy by an informed public for the recovery of threatened species; and public involvement in governance of the recovery process. These recommendations should be applicable broadly to reduce the likelihood and incidence of extinctions.  相似文献   

20.
Abstract:  Much has been written in recent years regarding whether and to what extent scientists should engage in the policy process, and the focus has been primarily on the issue of advocacy. Despite extensive theoretical discussions, little has been done to study attitudes toward and consequences of such advocacy in particular cases. We assessed attitudes toward science and policy advocacy in the case of marine protected areas (MPAs) on the basis of a survey of delegates at the First International Marine Protected Areas Congress. Delegates were all members of the international marine conservation community and represented academic, government, and nongovernmental organizations. A majority of respondents believed science is objective but only a minority believed that values can be eliminated from science. Respondents showed only partial support of positivist principles of science. Almost all respondents supported scientists being integrated into MPA policy making, whereas half of the respondents agreed that scientists should actively advocate for particular MPA policies. Scientists with a positivist view of science supported a minimal role for scientists in policy, whereas government staff with positivist beliefs supported an advocacy or decision-making role for scientists. Policy-making processes for MPAs need to account for these divergent attitudes toward science and advocacy if science-driven and participatory approaches are to be reconciled.  相似文献   

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