Eutrophication of Lake Tasaul, Romania—proposals for rehabilitation

Lake Tasaul on the Black Sea coast is highly eutrophic, but not strongly contaminated (heavy metals, PAHs, and organochlorine pesticides). Cyanophytes dominate phytoplankton by 67–94% and form frequent algal blooms. High primary production (up to 270 mg C_ass/m².h) and algal biomass (maximum chlorophyll a concentration 417 μg/l) may be controlled by light, as Secchi depth is often below 1 m. The main tributary, Casimcea River, provides high quantities of suspended matter and about 3 tons TP/year and 660 tons TN/year. Based on chemical and biological analysis as well as fishery investigations, we provide recommendations for Lake Tasaul rehabilitation.     

Eutrophication of Lake Tasaul,Romania—proposals for rehabilitation

Background, aim, and scope  The reclamation of nonferrous metal-polluted soil by phytoremediation requires an overall and permanent plant cover. To select the most suitable plant species, it is necessary to study metal effects on plants over the time, thereby checking that metals remain stored in root systems and not transferred to aerial parts. In this purpose, the seasonal and annual variations of metal bioaccumulation, transfer, and phytotoxicity in Trifolium repens and Lolium perenne grown in a Cd-, Pb-, and Zn-contaminated soil were also studied. Materials and methods  The experimental site was located near a closed smelter. In spring 2004, two areas were sown with T. repens and L. perenne, respectively. Thereafter, the samplings of plant roots and shoots and surrounding soils were realized in autumn 2004 and spring and autumn 2005. The soil agronomic characteristics, the Cd, Pb, and Zn concentrations in the surrounded soils and plant organs, as well as the oxidative alterations (superoxide dismutase [SOD], malondialdehyde [MDA], and 8-hydroxy-2′-deoxyguanosine [8-OHdG]) in plant organs were carried out. Results  Whatever the sampling period, metal concentrations in soils and plants were higher than background values. Contrary to the soils, the fluctuations of metal concentrations were observed in plant organs over the time. Bioaccumulation and transfer factors confirmed that metals were preferentially accumulated in the roots as follows: Cd>Zn>Pb, and their transfer to shoots was limited. Foliar metal deposition was also observed. The results showed that there were seasonal and annual variations of metal accumulation in the two studied plant species. These variations differed according to the organs and followed nearly the same pattern for the two species. Oxidative alterations were observed in plant organs with regard to SOD antioxidant activities, MDA, and 8-OHdG concentrations. These alterations vary according to the temporal variations of metal concentrations. Discussion  Metal concentrations in surrounded soils and plant organs showed the effective contamination by industrial dust emissions. Metals absorbed by plants were mainly stored in the roots. With regard to this storage, the plants seemed to limit the metal transfer to their aerial parts over the time, thereby indicating their availability for metal phytostabilization. Aerial deposition was another source of plant exposure to nonferrous metals. Despite the occurrence of metal-induced oxidative alterations in plant organs, both plant species seemed to tolerate a high metal concentration in soils. Conclusions  Taken together, these results indicated that T. repens and L. perenne were able to form a plant cover on highly Cd-, Pb-, and Zn-polluted soils, to limit the metal transfer to their aerial parts and were relatively metal-tolerant. All these characteristics made them suitable for phytostabilization on metal-contaminated soils. These findings also highlighted the necessity to take into account seasonal and annual variations for a future phytomanagement. Recommendations and perspectives  In this work, the behavior of plant species grown in metal-polluted soil has been studied during 2 years. Obviously, this time is too short to ensure that metals remain accumulated in the root system and few are transferred in aerial parts over the time. It is why regular monitoring should be achieved during more than a decade after the settlement of the plant cover. This work will be completed by the study of the T. repens and L. perenne effects on mobility of metals in order to evaluate the quantities of pollutants which could be absorbed by the biota and transferred to groundwater. Bioaccessibility tests could be also realized on polluted soils in order to evaluate the phytostabilization impacts on the exposition risks for humans.     

Does energy use and economic growth allow for environmental sustainability? An empirical analysis of Pakistan

Environmental Science and Pollution Research - The rapid growth of environmental pollution and the destruction of eco-systems force every individual economy to focus on environmentally friendly...     

Can Varying Concepts of Susceptibility in Risk Assessment Affect Particulate Matter Standards?

ABSTRACT

The Clean Air Act mandates that sensitive subpopulations be considered in setting standards to protect the public's health. The purposes of this paper are to point out different conceptualizations of susceptibility, examine how it is approached in risk-related processes, and recommend ways it may be more explicitly framed for risk assessment and management purposes. We studied the traditional risk assessment paradigm, the U.S. Environmental Protection Agency (EPA) guidelines and revised PM standard, discussions from recent interdisciplinary meetings, and peer-reviewed literature. Areas of controversy include what factors intrinsic and extrinsic to the host should be incorporated in susceptibility, what health endpoints are of concern, whether susceptibility is deterministic or stochastic, and whether it should be defined on an individual or population scale. Recent discussions about susceptibility applied to PM indicate that it needs to be more clearly defined and evaluated for scientific and policy purposes. We conclude that varying concepts of susceptibility can affect risk-related processes such as PM standard setting. We recommend that susceptibility be clearly defined in the problem statement of risk assessments and be addressed in a specific subsection of risk characterization, integrating all susceptibility findings from the prior three     

Does health expenditure matter for life expectancy in Mediterranean countries?

Environmental Science and Pollution Research - This research assesses the effect of health expenditure and sanitation on life expectancy in Mediterranean countries. We also consider other drivers...     

Does ICT lessen CO2 emissions for fast-emerging economies? An application of the heterogeneous panel estimations

Environmental Science and Pollution Research - This study examines the effects of electricity consumption, financial development, economic growth, trade and ICT on CO2 emissions in the...     

Does salt water intrusion constitute a mercury contamination risk for coastal fresh water aquifers?

Four different sampling surveys were carried out in 1998 to evaluate the possible causes of severe mercury contamination involving many wells spread over a vast territory along the coast of southern Tuscany (Italy). Several samples of groundwater and coastal sea water were collected to determine the Hg, Cl, Ar, He and N contents. Anthropogenic or deep-seated sources of the Hg involved in the contamination event can be excluded. The observed coupling of Hg pollution with progressive salt water intrusion along the coastal aquifer indicates a close causal relation between these two phenomena.     

Does economic policy uncertainty matter for carbon emission? Evidence from US sector level data

Environmental Science and Pollution Research - Economic policy uncertainty (EPU) will affect the external business environment of economic entities, which in turn affects the decision-making of...     

Does lipophilicity of toxic compounds determine effects on drought tolerance of the soil collembolan Folsomia candida?

The ability of Collembola to survive drought stress is crucial for their distribution in the terrestrial environment. Previous studies have suggested that several toxic compounds affect the drought tolerance of Folsomia candida in a synergistic manner and that these compounds have the feature in common that they elicit their toxicity by causing membrane damage. We hypothesised that the detrimental effect of toxic chemicals on drought tolerance in F. candida depends on the lipophilicity (log K(ow)) of the compound because a higher log K(ow) would mean a closer interaction with membranes. In this study the three chemicals 4-nonylphenol, pyrene and p,p'-DDE were tested. Surprisingly, 4-nonylphenol, with the lowest log K(ow), was the most potent with respect to reducing drought tolerance followed by pyrene, suggesting that interactions between drought tolerance and chemical stress do not depend on lipophilicity alone.     

Does renewable energy use enhance exchange rate appreciation and stable rate of inflation?

Environmental Science and Pollution Research - The current study is aimed at investigating the relationship between the use of renewable energy, the rate of currency exchange, and the rate of...     

Does small mammal prey guild affect the exposure of predators to anticoagulant rodenticides?

Ireland has a restricted small mammal prey guild but still includes species most likely to consume anticoagulant rodenticide (AR) baits. This may enhance secondary exposure of predators to ARs. We compared liver AR residues in foxes (Vulpes vulpes) in Northern Ireland (NI) with those in foxes from Great Britain which has a more diverse prey guild but similar agricultural use of ARs. Liver ARs were detected in 84% of NI foxes, more than in a comparable sample of foxes from Scotland and similar to that of suspected AR poisoned animals from England and Wales. High exposure in NI foxes is probably due to greater predation of commensal rodents and non-target species most likely to take AR baits, and may also partly reflect greater exposure to highly persistent brodifacoum and flocoumafen. High exposure is likely to enhance risk and Ireland may be a sentinel for potential effects on predator populations.     

High uptake of 2,4,6-trinitrotoluene by vetiver grass--potential for phytoremediation?

2,4,6-Trinitrotoluene (TNT) is a potent mutagen, and a Group C human carcinogen that has been widely used to produce munitions and explosives. Vast areas that have been previously used as ranges, munition burning, and open detonation sites are heavily contaminated with TNT. Conventional remediation activities in such sites are expensive and damaging to the ecosystem. Phytoremediation offers a cost-effective, environment-friendly solution, utilizing plants to extract TNT from contaminated soil. We investigated the potential use of vetiver grass (Vetiveria zizanioides) to effectively remove TNT from contaminated solutions. Vetiver grass plants were grown in hydroponic systems containing 40 mg TNTL(-1) for 8d. Aqueous concentrations of TNT reached the method detection limit ( approximately 1 microg L(-1)) within the 8-d period, demonstrating high affinity of vetiver for TNT, without any visible toxic effects. Results from this preliminary hydroponic study are encouraging, but in need of verification using TNT-contaminated soils.     

Does renewable energy consumption contribute to the development of low-carbon economy? Evidence from China

Environmental Science and Pollution Research - Stimulating renewable energy consumption has become a major strategic choice for China to both fulfill the international commitment to reduce carbon...     

Does digitalization matter in green preferences in nexus of output volatility and environmental quality?

Environmental Science and Pollution Research - The fact is that output volatility and carbon dioxide (CO2) emissions move together over the period. This empirical study examines the dynamic effect...     

Hybrid regimes of knowledge? Challenges for constructing scientific evidence in the context of the GMO-debate

Background, aim, and scope

Over the last two decades, there has been a remarkable shift of attention to the scientific and political fundamentals of the precautionary principle. The application of this principle has become a main strategy of coping with the different forms and problems related to non-knowledge. Thus, societies are increasingly confronted with the challenging and hitherto unresolved problem of political and technological decision-making under conditions of diverging framings of non-knowledge. At present, there seems to be no generally accepted scientific or institutional approach. This is why the fundamental question of how different scientific actors define and construct evidence is not answered yet. Hence, this paper is based on the consideration that the conflicts in risk policy concerning genetically modified organisms (GMO) depend on the unresolved conflicts about the diverging scientific strategies and structures of evidence-making between the epistemic cultures involved. Thus, this study investigates two questions: (1) do the epistemic strategies of evidence-making differ systematically with the scientific actors involved in the GMO-debate? (2) What consequences emerge considering institutionalized procedures of decision-making?

Main features

This article is based on a secondary analysis of findings and perspectives reported in the literature and on the methods of qualitative social empirical research, i.e., interviews with experts. A total number of 34 interviews were conducted to explore the different strategies of handling non-knowledge and constructing evidence. Actors from science, administration, business and NGOs were interviewed. In this way, typical epistemic cultures can be described. An epistemic culture is the constellation of methodological strategies, theoretical assumptions and practical-experimental settings which define in every speciality the ways how we know what we know.

Results

There are two main results. Firstly, it was worked out that the epistemic cultures involved in the GMO-debate use rather distinct strategies to define non-knowledge and to classify evidence. There are three types of constructing evidence, which correspond to different types of epistemic cultures. Secondly, the findings imply that the intensity of the conflicts in risk policy fields like the GMO-debate is due to a lack of knowledge politics. Usually, knowledge politics is restricted to the design of institutional procedures to compile knowledge provided by experts. The institutional setting of risk analysis and risk management is based on the premise of strict separation between knowledge and power. However, inadmissible mixing-up of knowledge and power is observable.

Discussion

It seems that non-knowledge leads to an epistemic no man’s land, and, hence, hybrid regimes of knowledge emerge. These regimes are hybrid with respect to the unclear and not explicitly reflected strategies of evidence-making. By lacking of knowledge politics, this situation opens up ‘windows of opportunity’ for actors with special interests in risk policy fields like the GMO-debate. Therefore, there is a difference between the visible institutionalized structures of risk policies and the rather invisible hybrid regimes of knowledge. Structure and scope of expertise have to be reflected and new instruments of knowledge politics have to be designed.

Conclusions

Different epistemic cultures can be qualified by describing their particular strategies of evidence-making. To solve the conflicts between these strategies, a meta-expertise is needed. Besides the institutionalized settings of knowledge politics, the underlying hybrid regimes of knowledge have to be identified.

Recommendations and perspectives

The concept of epistemic cultures and their strategies of evidence-making should be investigated more explicitly with respect to other risk policy fields The analysis of hybrid regimes of knowledge should be deepened by looking at the complex interactions between institutional, discursive and practical rules affecting risk assessment.

     

Does the potency of economic globalization and political instability reshape renewable energy usage in the face of environmental degradation?

Environmental Science and Pollution Research - Since renewable energy is essentially non-carbohydrate in nature, it can generate little or no pollutants and can therefore help in achieving both...     

The EU-project ERAPharm. Incentives for the further development of guidance documents?

- Triggered by the detection of a large variety of pharmaceuticals in surface waters, soils and groundwaters across the world (e.g. Halling- Sørensen et al. 1998, Daughton & Ternes 1999, Jones et al. 2001, Heberer 2002) and the widespread occurrence of endocrine active compounds and related effects in the environment (e.g. Purdom et al. 1994, Tyler et al. 1998, Vethaak et al. 2002), pharmaceuticals in the environment have become an issue for both the scientific and the public community. During the last few years, our understanding of the fate and effects of pharmaceuticals in the environment has progressed significantly. However, there are still a number of uncertainties concerning the effects of pharmaceuticals on the environment and the assessment of potential exposure (e.g. Hanisch et al. 2004, Salomon 2005). These uncertainties will be addressed by the EU-project ‘Environmental risk assessment of pharmaceuticals’ (ERAPharm). This project, a specific targeted research project, is carried out within the priority ‘Global change and ecosystems’ of the 6th framework programme of the European Union. ERAPharm has started on 1st October 2004; the project duration is three years.     

Does environmental engineering help rural industry development? Discussion on the impact of Taiwan’s “special act for forward-looking infrastructure” on rural industry development

Environmental Science and Pollution Research - This study investigated the impact of environmental engineering on existing venues, venues and operations management. First, the literature analysis...     

Does the smart city policy promote the green growth of the urban economy? Evidence from China

Environmental Science and Pollution Research - Urban governance is an important cornerstone in the modernization of a national governance system. The establishment of smart cities driven by...