Importance of exposure route for behavioural responses in <Emphasis Type="Italic">Lumbriculus variegatus</Emphasis> Müller (Oligochaeta: Lumbriculida) in short-term exposures to Pb

Goal, Scope and Background

Lumbriculus variegatus Müller (Oligochaeta), a common freshwater sediment-dweller, has frequently been used in toxicokinetic studies, although has been less used in ecotoxicity tests.

Methods

For the first time the Multispecies Freshwater Biomonitor® (MFB) was applied in a short-term whole-sediment toxicity test. The MFB automatically and quantitatively recorded the spontaneous locomotory behaviour of Lumbriculus variegatus in exposures with two compartments, water and sediment. The study questioned, whether the animals altered their locomotion depending on the compartment which was spiked with lead (Pb).

Results and Discussion

As in the exposures to Pb-contaminated water/clean sediment, the animals exposed to Pb-contaminated sediment/clean water showed higher activities in intermediate Pb-concentrations. This indicates, that spontaneous locomotory activity is affected by Pb-concentrations at sublethal levels regardless of whether the Pb-concentration is found in the water or in the sediment, because these animals use both environmental compartments simultaneously. However, within the same Pb-levels, the animals showed higher locomotory activity in contaminated water compared with contaminated sediment. This indicates a possible tendency to withdraw from (‘avoidance’) contaminated water into the clean sediment compartment, whereas there was no withdrawal from contaminated sediment into clean water. The latter might be explained by the fact that withdrawal from sediment to water might increase the risk of predation and drift in nature, whereas retracting to sediment might provide shelter.

Conclusions

The study showed that spontaneous locomotory responses of L. variegatus to Pb depend on whether the water or sediment is contaminated. The study also concluded that the Multispecies Freshwater Biomonitor® can be applied effectively in sediment toxicity testing.

Recommendations and Perspectives

More emphasis should be given to the interactions of water/sediment in sediment ecotoxicity tests to better simulate field conditions and increase ecological realism in risk assessment, especially as quantitative recording methods exisit.

     

A source classification framework supporting pollutant source mapping,pollutant release prediction,transport and load forecasting,and source control planning for urban environments

Purpose

Implementation of current European environmental legislation such as the Water Framework Directive requires access to comprehensive, well-structured pollutant source and release inventories. The aim of this work was to develop a Source Classification Framework (SCF) ideally suited for this purpose.

Methods

Existing source classification systems were examined by a multidisciplinary research team, and an optimised SCF was developed. The performance and usability of the SCF were tested using a selection of 25 chemicals listed as priority pollutants in Europe.

Results

The SCF is structured in the form of a relational database and incorporates both qualitative and quantitative source classification and release data. The system supports a wide range of pollution monitoring and management applications. The SCF functioned well in the performance test, which also revealed important gaps in priority pollutant release data.

Conclusions

The SCF provides a well-structured approach for European pollutant source and release classification and management. With further optimisation and demonstration testing, the SCF has the potential to be fully implemented throughout Europe.

     

The Rhine red,the fish dead—the 1986 Schweizerhalle disaster,a retrospect and long-term impact assessment

Background

The November 1, 1986 fire at a Sandoz Ltd. storehouse at Schweizerhalle, an industrial area near Basel, Switzerland, resulted in chemical contamination of the environment. The storehouse, which was completely destroyed by the fire, contained pesticides, solvents, dyes, and various raw and intermediate materials. The majority of the approximately 1,250 t of stored chemicals was destroyed in the fire, but large quantities were introduced into the atmosphere, into the Rhine River through runoff of the fire-fighting water, and into the soil and groundwater at the site. The chemicals discharged into the Rhine caused massive kills of benthic organisms and fish, particularly eels and salmonids. Public and private reaction to the fire and subsequent chemical spill was very strong. This happened only a few months after the Chernobyl accident and it destroyed the myth of immunity of Switzerland regarding such catastrophes.

Aim

This article reviews the damaging events of November 1986 and aims at striking stock two decades later.

Results and discussion

In the aftermath of this once-per-century accident, the aim was to obtain new knowledge for the environmental sciences and to achieve progress for water pollution control issues. The following themes are discussed: mitigation measures by the chemical industry and by the governmental authorities, activities of environmental protection organizations, chemical and biological monitoring, alert organization, ecological damages, ecotoxicological effects assessment, recovery and alteration of the river biology, return of the salmon, drinking water supplies, research programs, education of environmental scientists, and visions for the future.

Conclusions

The catastrophic pollution of the Rhine in November 1986 has triggered by the openly visible damages of the river biology that subsequently significant progress was made towards the prevention of such environmental catastrophes. The crucial risk reduction measures in the chemical industry, legal regulations and controls as well as chemical and biological monitoring of the river water quality were substantially improved. Politics and chemical industry have learned their lectures and have proceeded accordingly.

Recommendations

A drastic acute contamination, as it has happened at Schweizerhalle in 1986, is clearly recognizable by the toxic effects, which it is causing. This can lead to mitigation activities, which are positive considering a long-term perspective. However, the less obvious effects of chronic water pollution should receive more attention as well as the ongoing alteration of the biocenosis. A high water quality must be demanded for using water from the Rhine to produce drinking water. In that context, micropollutants should also be considered and particular attention should be payed to emerging contaminants.

Perspectives

The big chemical storehouse fire of 1986 had an important impact on the transboundary cooperation and has improved the willingness for international cooperation. The fire catastrophe of Schweizerhalle has triggered many activities in particular for the Rhine River. Overall, the effects are positive on the basis of a long-term perspective. The applied whole basin approach gives an example on a global basis for other river systems, which still are more heavily polluted.

     

Heavy metals in untreated/treated urban effluent and sludge from a biological wastewater treatment plant

Background, Aim and Scope

The presence of heavy metals in wastewater is one of the main causes of water and soil pollution. The aim of the present study was to investigate the removal of Cd, Cu, Pb, Hg, Mn, Cr and Zn in urban effluent by a biological wastewater treatment, as well as to quantify the levels of As, Be, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Sn, Tl, V and Zn in dewatering sludge from the Biological Wastewater Treatment Plant to Ribeirão Preto (RP-BWTP), Brazil.

Materials and Methods

Concentrations of Cd, Cr, Cu, Mn and Pb in wastewater and those of Ni in sludge were determined by atomic absorption spectrophotometry with graphite furnace atomization. Mercury concentrations in wastewater were measured by hydride generation atomic spectrophotometry, and Zn levels were determined by atomic absorption spectrophotometry using acetylene flame. In sludge, the levels of As, Be, Cd, Cr, Cu, Fe, Hg, Mn, Pb, Sn, Tl, V and Zn were determined by inductively coupled plasma-mass spectrometry.

Results

The percentages of removal efficiency (RE) were the following: Hg 61.5%, Cd 60.0%, Zn 44.9%, Cu 44.2%, PB 39.7%, Cr 16,5% and Mn 10.4%. In turn, the mean concentrations (mg/kg) of metals in dewatering sludge followed this increasing order: Tl (<0.03), Hg (0.31), Be (0.43), As (1.14), Cd (1.34), V (59.2), Pb (132.1), Sn (166.1), Cr (195.0), Mn (208.1), Ni (239.4), Cu (391.7), Zn (864.4) and Fe (20537).

Discussion

The relationship between metal levels in untreated wastewater, as well as the removal efficiency are in agreement with previous data from various investigators, It is important to note that metal removal efficiency is not only affected by metal ion species and concentration, but also by other conditions such as operating parameters, physical, chemical, and biological factors.

Conclusions

Metal values recorded for treated wastewater and sludge were within the maximum permitted levels established by the Environmental Sanitation Company (CETESB), São Paulo, Brazil.

Recommendations

There is an urgent need for the authorities who are responsible for legislation on sludge uses in agriculture of establishing safety levels for As, Be, Hg, Sn, Tl and V.

Perspectives

According to the current metal levels, RP-BWTP sludge might be used for agriculture purposes. However, for an environmentally safe use of sewage sludge, further studies including systematic monitoring are recommended. Annual metal concentrations and predicted variations of those elements in the sludge should be monitored.

     

Genotoxicity potential of a new natural formicide

Background, aim, and scope

Assessment of environmental impacts from pesticide utilization should include genotoxicity studies, where the possible effects of mutagenic/genotoxic substances on individuals are assessed. In this study, the genotoxicity profile of the new formicide Macex® was evaluated with two genotoxicity tests, namely, the micronucleus test with mouse bone marrow and Vicia faba, and a mutagenicity test using the Ames Salmonella assay.

Materials and methods

The bacterial reverse mutation test (Salmonella typhimurium strains TA97, TA98, TA100, TA102, and TA1535), the Vicia root tip and mouse micronucleus tests were conducted according to published protocols.

Results

In the range of the formicide Macex® concentrations tested from 0.06 to 1.0 g?L^?1 (or mgkg^?1 in the mouse test), no genotoxicity was observed in the prokaryotic or eukaryotic test organisms. However, at Macex® concentrations of 0.5 g?L^?1 and above a significant decrease in the mitotic index (P?≤?0.05) in the V. faba was observed. Micronucleus formation was likewise increased in the test organism at concentrations starting at 2.0 g?L^?1.

Conclusions

These data allow us to classify this natural formicide preparation as a product with no geno-environmental-impact when applied at recommended concentrations.

     

A preliminary investigation of the environmental impact of a thermal power plant in relation to PCB contamination

Purpose

The most significant application of polychlorinated biphenyls (PCBs) is in transformers and capacitors. Therefore, power plants are important suspected sources for entry of PCBs into the environment. In this context, the levels and distribution of PCBs in sediment, soil, ash, and sludge samples were investigated around Seyitömer thermal power plant, Kütahya, Turkey. Moreover, identity and contribution of PCB mixtures were predicted using the chemical mass balance (CMB) receptor model.

Methods

United States Environmental Protection Agency methods were applied during sample preparation, extraction (3540C), cleanup (3660B, 3665A, 3630C), and analysis (8082A).

Results

ΣPCB concentrations in the region ranged from not detected to 385 ng/g dry weight, with relatively higher contamination in sediments in comparison to soil, sludge, and ash samples collected from around the power plant. Congener profiles of the sediment and soil samples show penta-, hexa-, and hepta-chlorobiphenyls as the major homolog groups. The results from the CMB model indicate that PCB contamination is largely due to Clophen A60/A40 and Aroclor 1254/1254(late)/1260 release into the sediment and sludge samples around the thermal power plant.

Conclusions

Since there are no other sources of PCBs in the region and the identity of PCB sources estimated by the CMB model mirrors PCB mixtures contained in transformers formerly used in the plant, the environmental contamination observed especially in sediments is attributed to the power plant. Release of PCBs over time, as indicated by the significant concentrations observed even in surface samples, emphasizes the importance of the need for better environmental management.

     

Heavy metal contamination in the vicinity of an industrial area near Bucharest

Background, aim, and scope

Heavy metals such as lead are well known to cause harmful health effects. Especially children are particularly susceptible to increased levels of lead in their blood. It is also a fact that lead concentration is increasing in the environment due to increased anthropogenic activity. The risk of heavy metal contamination is pronounced in the environment adjacent to large industrial complexes. In a combined case study, the environmental pollution by heavy metals was related to children’s health in the vicinity of an industrial area located 4 km south-east from Bucharest about 2 km east from the nearest town—Pantelimon. This site includes companies processing different, nonferrous solid wastes for recovery of heavy metals and producing different nonferrous alloys and lead batteries. In this paper, mainly the results of environmental sampling and analyses are summarized.

Materials and methods

Water, soil, and atmospheric deposition samples were collected from different locations within 3 km from the industrial area. For comparison, samples were also taken from Bucharest. Water samples were filtered (<0.45 μm), extracted by salpetric acid, and quantified by ICP-OES and ICP-MS. Soil samples were dried, sieved (<2 mm), extracted by aqua regia and analyzed by AAS. In order to quantify the atmospheric deposition, three kinds of permanently open collecting pots were used on nine different sites between August and November 2006.

Results

At most sampling locations, the heavy metal concentrations in soil decrease with increasing distance to the presumably major source of pollution. Highest heavy metal concentrations were found in 10–20 cm soil depths. There were also decreasing heavy metal concentrations for atmospheric deposition with increasing distance to the industrial site. In surface and groundwater samples, traces of zinc, copper and lead were detected.

Discussion

The heavy metal concentrations in soil were increased in the study area, mostly under legal action limits in low-concern areas (e.g., 1,000 mg Pb/kg dry soil), but often above action limits for high-concern areas (100 mg Pb/kg dry soil) such as populated areas. The soluble lead concentrations in water samples indicate a need for monitoring and assessing water quality in more detail. The results for atmospheric deposition showed increased dust precipitation and heavy metal loads in the study area compared to Bucharest. However, based on mass flow balance calculations, the actual atmospheric deposition of heavy metals must be much lower than it was in the past decades.

Conclusions

It was shown that highest lead values in water, soil and atmospheric deposition are rather to be found near the investigated industrial site than at the control sites in Bucharest. Our results correspond very well with results that show that children from Pantelimon have significantly increased lead concentrations in their blood compared to children in Bucharest. The increased lead contamination around the investigated industrial area is likely to have caused the increased exposure for children living in Pantelimon.

Recommendations and perspectives

In high-concern areas, such as found in populated areas, further measures have to be taken to avoid health risks for people living in these areas. The measures already taken to reduce emissions from the industrial site will help to avoid further increases in heavy metal concentrations. In areas with exceeded action limits, measures have to be taken as required by law. Detailed risk assessments could help to take necessary actions to protect public health in this area. The public should be informed about the potential hazards of eating plants grown in that area. Educational programs for schools, informing children about the contamination, should lead to a better understanding of environmental problems and a more sustainable behavior in the future.

     

Sorption of polycyclic aromatic hydrocarbons (PAHs) to low and high density polyethylene (PE)

Background, aim, and scope

According to their high sorption capacity polyethylene (PE) passive samplers are often used for the analysis of polycyclic aromatic hydrocarbons (PAHs) in the aquatic environment. PE is also one of the primary synthetic polymers found in oceans, and sorption of PAHs to marine PE debris may determine PAH exposure and therefore hazards in marine ecosystems. Thus, an understanding of the sorption process is of great importance. In the present study, the sorption of several PAHs with different polarities to low density polyethylene (LDPE) and high density polyethylene (HDPE) was studied in order to improve our understanding of the influence of material properties on the Fickian diffusion of PAHs into PE.

Materials and methods

Batch sorption experiments were performed with aqueous solutions containing acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, and LPDE or HDPE pellets. Samples were shaken in the dark at 20?±?1°C for 16 time intervals within one week. Concentrations of PAHs were determined in the aqueous samples using solid-phase microextraction coupled with gas chromatography–mass spectrometry. The distribution coefficients (K _PE) between PE and water were estimated from different models reported in the literature. Kinetic sorption of the PAHs into the plastic pellets was described by a diffusion model based on Fick’s second law in spherical coordinates.

Results and discussion

A comparison between different models describing the equilibrium distribution of PAHs between PE and water revealed that the sorption equilibrium seemed to be driven by parameters other than, or in addition to, organic carbon. For both plastic types, diffusion coefficients decreased while the molecular weight of the PAHs increased which indicates a hindered diffusion through the matrix as a result of a larger molecule size. Higher diffusion coefficients were derived for LPDE than for HDPE indicating a greater sorption velocity for LPDE according to the lower polymer density.

Conclusions

Our results revealed that equilibrium time could be shortened during passive sampling as polymer membranes of lower density are used. In some areas, marine ecosystems may not be in equilibrium with respect to concentrations of organic contaminants and abundance of marine plastic debris. In such cases, different polymer densities should be taken into account in risk assessments.

     

Chemical,biological, and ecotoxicological assessment of pesticides and persistent organic pollutants in the Bahlui River,Romania

Background, aim, and scope

Current knowledge on environmental impacts of industrial activities in Romania, particularly persistent organic pollutants (POPs), indicates that environmental standards of the European Union are not systematically met. In our study area, additional sources of POPs are agriculture and domestic wastes. Very scarce information is available upon environmental contaminations and effects. In the present study, we investigated the chemical pollution and their eventual impact on the ecosystem by measuring POPs and by using biological indicators of pollution.

Materials and methods

The survey was carried out at six main sample sites along the Bahlui River. Sediments were chemically analysed for their content in polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs)—hexachlorocyclohexanes (HCHs) isomers and the dichlorodiphenyl trichloroethane (DDT) family. River water was biologically monitored at the level of phytoplankton and benthic invertebrates’ communities. Water samples from six locations have been analyzed for algal species composition and correspondence to various water quality indices. Biological samples have been taken from the same locations so as to calculate the macroinvertebrate indices. In the most polluted areas, as revealed by previous methods, toxicity was tested by exposing the green alga Pseudokirchneriella subcapitata and the cladoceran Daphnia magna to various dilutions of water sample.

Results

Important concentrations of POPs were identified only in sediments at river mouths (sites S5 and S6). Along the year, the sum of PCB concentrations ranged between 3 and 10 ng/g dw (S5), and between 4 and 26 ng/g dw (S6). Concentration of HCHs ranged between 0.4 and 3 ng/g dw (both S5 and S6) with a higher contribution of the gamma-HCH (30–70%), followed by beta-HCH (20–50%). The beta-HCH isomer was found at lower concentrations or even not detected in outer city sites. DDTs were found at higher concentrations than HCHs and ranged between 0.18 and 4 ng/g dw (S5) and between 0.56 and 18 ng/g dw (S6). The parent compound, p,p′-DDT, could be detected only in low concentrations (up to 5 ng/g dw) and contributed with less than 30% to the sum of DDTs in sediment. The principal contributors of the ΣDDTs in sediment were p,p′-DDE, and p,p′-DDD. The o,p′-DDD and DDT isomers were minor contributors to the sum of DDT. PAHs were found at higher concentrations than DDTs and ranged between 6 and 36 ng/g dw (S5) and between 36 and 155 ng/g dw (S6). Fluoranthene was predominant (up to 40%), followed by phenantrene (up to 30%), naphthalene (up to 35%), and benzo-(g,h,i)-perylene (up to 23%). The saprobity index and the diatom index increased from springs to river mouth, indicating a decrease in the water quality, but within the limits of moderate pollution. The saprobity index varied between 1.99 at spring to 2.70 at mouth. The diatom index varied from 3.48 to 3.14. The species’ richness in phytoplankton has a less clear pattern along the river, but in general, it appears to be negatively influenced by pollution. At the level of biological consumer species, the analyses of the macroinvertebrates confirm the situation and the tendency shown with algae. In addition, the Shannon–Wiener index, the Pielou evenness index, and the McNaughton dominance index indicate a peculiar pattern: invertebrate communities appear to a have a more stable structure along the river, with visible shifts at springs and at river mouths. Water toxicity testing indicates low toxicity of river waters around the city of Iasi, with two notable exceptions: the point pollution at the domestic wastewater treatment discharge and at the old open-air deposit of domestic solid wastes. Another important result was that tested algae appeared to be more readily affected than tested cladoceran: EC₅₀ (percent effluent) was 16 in algae and 28 in cladocerans. The slope of toxic effect was also much steeper in cladocerans (6) than in algae (1.8), which means that the toxic effect is more sudden on the tested invertebrates than on the tested algae.

Discussion

Pollutant concentrations reported herein are lower or similar than those reported for the sediments by earlier studies (RIZA 2000; Dragan et al., Int J Environ Anal Chem 86:833–842, 2006). Ratios of individual PAH compounds indicate important pyrolytic inputs and suggest that PAHs in the area are derived from the combustion of fossil fuels. Biologically, the waters appear to be beta-mesosaprobic towards alpha-mesosaprobic according to the saprobic index classification and undergo moderate pollution according to the diatom index classification. Water quality decreases from springs to river mouths. Algal species richness index has a less clear pattern along the river. Water toxicity is low, but certain sources of point pollution require increased attention.

Conclusions

The water quality is better than expected, probably because of the drop in pollution intensity following the collapse of local agricultural and industrial activity following the fall of communism in 1989. Nevertheless, further studies will be needed to confirm and refine our results. While this study draws no strident alarm, it appeals for high attention, particularly because the economic activity in the area is expected to increase.

Recommendations and perspectives

Future close monitoring will be necessary for insuring compliance with the Water Framework Directive, and for refining standards and understanding of the local situation, but with relevance for the wider international community. On the basis of the situation described in the present study, we recommend that future studies dedicate specific efforts to point pollution and effluent toxicity, particularly around the city of Iasi. For a better understanding of pollution and its effects, we recommend pursuing the type of multidisciplinary investigations proposed by the present study: chemical, ecotoxicological, and ecological. We also recommend that new methods should be developed and/or refined, like the empirical determination of partitioning coefficients in water and soils, process-based toxicity methods in ecotoxicological assessments, searching for interactions between pollution, producers, and consumers in aquatic ecosystems. We also recommend preference for cheaper survey methods, as these will be more applicable locally.

     

Response to W. Kramer: The human sex odds at birth after the atmospheric atomic bomb tests,after Chernobyl,and in the vicinity of nuclear facilities: comment (doi:10.1007/s11356-011-0644-8)

Introduction

This paper is in response to criticism of our article “The human sex odds at birth after the atmospheric atomic bomb tests, after Chernobyl, and in the vicinity of nuclear facilities” published in Environ Sci Pollut Res 18(5):697–707, 2011.

Methods

Our findings and methods concerning the disturbed human sex odds at birth have been criticized in this journal for being artifacts of data mining, that the concept of statistical significance was misunderstood, and that confounding factors have not been accounted for. Here, we show that this criticism has no basis. We applied well-established statistical methods to large official data sets, and confounding is less important at the level of secular sex odds trends in aggregated annual figures from countries or continents.

Results and conclusions

Moreover, our results are strengthened by recent findings concerning increased infant death sex odds in Germany and increased Down syndrome prevalence at birth across Europe after Chernobyl. Prompted by our studies, an official investigation in Lower Saxony, Germany, by the “Niedersächsisches Landesgesundheitsamt (NLGA)” confirmed our observation of severely escalated sex odds within 40 km distance from the nuclear storage site in Gorleben, Germany.

     

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.

     

Quantification and characterization of vehicle-based polycyclic aromatic hydrocarbons (PAHs) in street dust from the Tamale metropolis,Ghana

Objective

Concentrations of polycyclic aromatic hydrocarbons (PAHs) in street dust in the Tamale metropolis, Ghana, have been measured in this study.

Results

The concentrations of the various types of PAHs identified in street dust samples from high vehicular traffic density in the metropolis are as follows: naphthalene, 10,000 μg/kg; acenaphthylene, 13,000 μg/kg; acenaphthene, 76,000 μg/kg; fluorene, 18,900 μg/kg; phenanthrene, 40,000 μg/kg; anthracene, 21,000 μg/kg; fluoranthene, 35,200 μg/kg; pyrene, 119,000 μg/kg; benzo[a]anthracene, 17,700 μg/kg; chrysene, 10,600 μg/kg; benzo[k]fluoranthene, 18,700 μg/kg; benzo[a]pyrene, 10,900 μg/kg and benzo[g, h, i]perylene, 21,000 μg/kg. Calculation of the phenanthrene/anthracene ratio indicated that the PAHs identified in this study were from vehicular fallout as the ratio was less than 10.

Conclusion

It is clear from the results of the study that road users in the Tamale metropolis, especially hawkers, are exposed to the harmful effects of PAHs, and this suggests the need for the establishment of mitigation measures by the regulatory agencies.

     

Ecotoxicological research and related legislation in Serbia

Introduction

Several hot spots of severe freshwater pollution and sediment contamination (mostly heavy metals, polyaromatic hydrocarbons and polychlorinated biphenyls) have been identified in Serbia as the consequence of outdated environmental legislation, negligible amounts of properly treated waste waters and accidental spills.

Discussion

Since ecotoxicological methods have never been incorporated into risk assessment procedures, mandatory effluent discharge or ambient water monitoring programmes, ecotoxicological research, based on bioaccumulation studies, conventional ecotoxicological tests and, recently, biomarkers of exposure and effect have been restricted to independent small- to medium-scale studies, conducted, basically, to confirm, underline or oppose the results of chemical-based monitoring and to lament on inadequate environmental regulations/policy and management practice. Although hot and unresolved ecotoxicological problems still remain beyond the reach of ecotoxicological research currently conducted in Serbia, or are tackled only sporadically, it is to be expected that on-going research and institutional capacity building should, hopefully, increase the competence and competitiveness of scientific community and speed up the process of harmonisation of national environmental legislation and policy with European Union.

     

Behavioural ecotoxicology,an “early warning” signal to assess environmental quality

Background

In this review, the position of behavioural ecotoxicology within the available means to assess the status of marine environments is described as filling the gap for the needed “early warning” signals. A few examples of studies performed since the 1960s are discussed to highlight the sensitivity of these approaches in investigating the effects of chemicals, including priority pollutants and emerging contaminants, relative to conventional toxicity tests measuring survival.

Discussion

The advantage of the behavioural response is due to the integration of biochemical and physiological processes that reflect changes at higher levels of organisation with ecological relevance. Avoidance often represents a behavioural symptom easily detected in many animals exposed to contaminants and would be a useful test to explore more widely. This rapid response would reflect a defence mechanism protective against further exposure and the potential development of more pronounced deleterious effects, whilst in some cases, escape could lead to the relocation of a species with negative consequences. An investigation of the avoidance behaviour of mud shrimp, Corophium volutator, along with the chemical analyses of sediments and amphipods to assess the quality of harbour sediments is summarised. The body burden of the amphipods was 1,000 times lower than the one associated with narcosis, emphasizing the sensitivity of this endpoint. The application of this acute toxicity test is briefly compared to additional work that involved intertidal mussels collected in the field.

Conclusions

Recent research undertaken with mud snails, Ilyanassa obsoleta, and harbour sediments confirmed the usefulness of the escape behaviour as an assessment tool. However, the limits of the state of knowledge regarding the fate of contaminants in species with the ability to metabolise contaminants is further discussed along with directions to be pursued to address questions arising from the reviewed literature.

     

Adapting a geographical information system-based water resource management to the needs of the Romanian water authorities

Background, aim, and scope

The need for global and integrated approaches to water resources management, both from the quantitative and the qualitative point of view, has long been recognized. Water quality management is a major issue for sustainable development and a mandatory task with respect to the implementation of the European Water Framework Directive as well as the Swiss legislation. However, data modelling to develop relational databases and subsequent geographic information system (GIS)-based water management instruments are a rather recent and not that widespread trend. The publication of overall guidelines for data modelling along with the EU Water Framework Directive is an important milestone in this area. Improving overall water quality requires better and more easily accessible data, but also the possibility to link data to simulation models. Models are to be used to derive indicators that will in turn support decision-making processes. For this whole chain to become effective at a river basin scale, all its components have to become part of the current daily practice of the local water administration. Any system, tool, or instrument that is not designed to meet, first of all, the fundamental needs of its primary end-users has almost no chance to be successful in the longer term.

Materials and methods

Although based on a pre-existing water resources management system developed in Switzerland, the methodological approach applied to develop a GIS-based water quality management system adapted to the Romanian context followed a set of well-defined steps: the first and very important step is the assessment of needs (on the basis of a careful analysis of the various activities and missions of the water administration and other relevant stakeholders in water management related issues). On that basis, a conceptual data model (CDM) can be developed, to be later on turned into a physical database. Finally, the specifically requested additional functionalities (i.e. functionalities not provided by classical commercial GIS software), also identified during the assessment of needs, are developed. This methodology was applied, on an experimental basin, in the Ialomita River basin.

Results

The results obtained from this action-research project consist of a set of tangible elements, among which (1) a conceptual data model adapted to the Romanian specificities regarding water resources management (needs, data availability, etc.), (2) a related spatial relational database (objects and attributes in tables, links, etc.), that can be used to store the data collected, among others, by the water administration, and later on exploited with geographical information systems, (3) a toolbar (in the ESRI environment) offering the requested data processing and visualizing functionalities. Lessons learned from this whole process can be considered as additional, although less tangible, results.

Discussion

The applied methodology is fairly classical and did not come up with revolutionary results. Actually, the interesting aspects of this work are, on the one hand, and obviously, the fact that it produced tools matching the needs of the local (if not national) water administration (i.e. with a good chance of being effectively used in the day-to-day practice), and, on the other hand, the adaptations and adjustments that were needed both at the staff level and in technical terms.

Conclusions

This research showed that a GIS-based water management system needs to be backed by some basic data management tools that form the necessary support upon which a GIS can be deployed. The main lesson gained is that technology transfer has to pay much attention to the differences in existing situations and backgrounds in general, and therefore must be able to show much flexibility. The fact that the original objectives could be adapted to meet the real needs of the local end-users is considered as a major aspect in achieving a successful adaptation and development of water resources management tools. Time needed to setup things in real life was probably the most underestimated aspect in this technology transfer process.

Recommendations and perspectives

The whole material produced (conceptual data model, database and GIS tools) was disseminated among all river basin authorities in Romania on the behalf of the national water administration (ANAR). The fact that further developments, for example, to address water quantity issues more precisely, as envisaged by ANAR, can be seen as an indication that this project succeeded in providing an appropriate input to improve water quality in Romania on the long term.

     

The International Association for Danube Research (IAD)—portrait of a transboundary scientific NGO

Introduction

The International Association for Danube Research (IAD), a legal association (Verein) according to Austrian law, presently consists of 13 member countries and 12 expert groups covering all water-relevant scientific disciplines. IAD, founded in 1956, represents a traditional and significant stakeholder in the Danube River Basin, fulfilling an important task towards an integrative water and river basin management requested by the EU Water Framework Directive.

Discussion

IAD, stretching between basic and applied research, adapted its strategy after the major political changes in 1989. IAD fosters transdisciplinary and transboundary projects to support integrative Danube River protection in line with the governmental International Commission for the Protection of the Danube River (ICPDR) in which IAD has had observer status since 1998. Recent scientific outputs of IAD encompass, amongst others, a water quality map of the Danube and major tributaries, the Sturgeon Action Plan, hydromorphological mapping of the Drava, a macrophyte inventory, and a Mures River study. Further information about IAD can be found on our website http://www.iad.gs.

     

Antioxidative responses of duckweed (<Emphasis Type="Italic">Lemna minor</Emphasis> L.) to short-term copper exposure

Goal, Scope and Background

Elevated concentrations of copper in the environment result in accumulation of the metal in plants and cause an increase in reactive oxidative species (ROS). The first response to elevated amounts of ROS is increased levels of enzymatic and non-enzymatic antioxidants that reduce oxidative stress. The aim of our study was to evaluate the early stages of antioxidative responses to the low copper concentrations usually present in moderately polluted environments. In addition, some other parameters were examined to evaluate the effect of copper on plants.

Methods

Duckweed (Lemna minor L.) was exposed to different concentrations of copper sulphate for up to 24 hours. Glutathione concentration and enzymatic activities of catalase, guaiacol peroxidase and glutathione reductase were measured spectrophotometrically. Additionally, delayed and prompt chlorophyll fluorescence was measured by luminometry and fluorometry, respectively. The accumulation of copper in plants exposed for 24 hours to various concentrations of copper sulphate was measured by flame atomic absorption spectrophotometry.

Results

The treatment of plants with copper sulphate resulted in an immediate decrease of the glutathione pool, which was replenished after 24 hours at CuSO₄ concentrations lower than 2 μM. Higher CuSO₄ concentrations caused a decrease of reduced glutathione. The responses of the antioxidant enzymes glutathione reductase, guaiacol peroxidase and catalase to CuSO₄ differed during the first six hours of exposure, but their enzyme activities all increased after 24 hours of exposure. All these enzymes displayed biphasic activity curves with maximum values between 0.5 μM and 1 μM CuSO₄. The response of guaiacol peroxidase was the most pronounced and statistically significantly specific and that of catalase the least. Delayed chlorophyll fluorescence decreased after exposure to 1 μM CuSO₄, but no significant effect on maximum quantum yield of photosystem II (Fv/Fm) was observed. L. minor accumulated relatively high concentrations of copper. The accumulation rate was higher at lower concentrations of copper in the test medium (up to 2 μM CuSO₄) than at concentrations above 2 μM CuSO₄.

Discussion

One of the most pronounced antioxidative responses to copper exposure was modified levels of oxidized and reduced forms of glutathione. The decrease of the glutathione pool is most probably coupled with induced production of phytochelatins. Antioxidative enzymes showed the biphasic enzyme activity characteristic of stress response. Guaiacol peroxidase exhibited the greatest significant increase of activity, even at higher CuSO₄ concentrations at which the activity of catalase and glutathione reductase dropped. The intensity of delayed chlorophyll fluorescence decreased, indicating reduced photosynthesis of plants under stress. All the measured parameters showed that plants respond to even low copper concentrations very soon after exposure. The accumulation rate of copper in duckweed tissues indicates that L. minor is an accumulator species.

Conclusions

The synchronized and prompt inducibility of antioxidants indicates their involvement in a general plant defence strategy for coping with metal-induced oxidative stress. Glutathione concentration and guaiacol peroxidase activity were found to be the most sensitive of the early indicators of exposure to copper concentrations present in polluted water bodies.

Recommendation and Perspectives

The experimental design of the present study allowed us to compare the sensitivity of various methods and parameters for detecting plant responses to heavy metal-induced oxidative stress. The level of glutathione and the enzyme activities of guaiacol peroxidase and glutathione reductase could be used as a rapidly determined early warning system in toxicity studies.

     

EU Water Framework Directive and Stockholm Convention Can we reach the targets for priority substances and persistent organic pollutants?

Background, aim and scope  

Water is a renewable resource and acceptable quality is important for human health, ecological and economic reasons, but human activity can cause great damage to the natural aquatic environment. Managing the water cycle in a sustainable way is the key to protect natural resources and human health. On a global level, the microbiological contamination of water sources is a major problem in connection with poverty and the United Nations Millennium Development Declaration is an important initiative to handle this problem. In terms of environmental health, persistent organic pollutants (POPs) circulate globally; as they travel long distances, they are found in remote areas far from their original source of application and can cause damage wherever they move to. On a global scale, United Nations Environmental Programme (UNEP) issued the Stockholm Convention to reduce POPs; in the European Union (EU), one intention of the Water Framework Directive (WFD) is to reach the good chemical status of waters; beside these regulations, there are other directives in support of these goals. The aim of this paper is to discuss whether the Stockholm Convention and the WFD allows meeting the targets of protection of human and environmental health, which are established in the different directives and how could we approach the targets.     

An assessment of the potential toxicity of runoff from an urban roadscape during rain events

Goal, Scope and Background

The potential negative impact of urban storm water on aquatic freshwater ecosystems has been demonstrated in various studies with different types of biological methods. There are a number of factors that influence the amount and bioavailability of contaminants in storm water even if it is derived from an area with a fairly homogenous land use such as a roadscape where a variation in toxicity during rain events might be expected. There are only a few previous investigations on the toxicity of highway runoff and they have not explored these issues extensively. The main objective of this study is therefore to characterize the potential toxicity of highway runoff during several rain events before it enters a detention pond in VästerOas, Sweden, using laboratory bioassays with test organisms representing various functional groups in an aquatic ecosystem. The results are to be used for developing a monitoring program, including biological methods.

Materials and Methods

The storm water was sampled before the entrance to a detention pond, which receives run-off from a highway with approximately 20,000 vehicles a day. The drainage area, including the roadscape and vegetated areas, is 4.3 ha in size. Samples for toxicity tests were taken with an automatic sampler or manually during storm events. In total, the potential toxicity of 65 samples representing 15 different storm events was determined. The toxicity was assessed with 4 different test organisms; Vibrio fischeri using the Microtox® comparison test, Daphnia magna using Daphtoxkit-F?agna, Thamnocephalus platyurus using the ThamnotoxkitF? and Lemna minor, duckweed using SS 028313.

Results and Discussion

Of the 65 samples, 58 samples were tested with DaphniatoxkitF?agna, 57 samples with the Microtox® comparison test, 48 samples with ThamnotoxkitF? and 20 samples with Lemna minor, duckweed. None of the storm water samples were toxic.No toxicity was detected with the Lemna minor test, but in 5 of the 23 samples tested in comparison to the control a growth stimulation of 22–46% was observed. This is in accordance with the chemical analysis of the storm water, which indicated rather large concentrations of tot-N and tot-P. In addition to the growth stimulation, morphological changes were observed in all the 5 samples from the winter event that was sampled. The lack of toxicity observed in our study might be due to a lower traffic intensity (20,000 vehicles/day) at the site and the trapping of pollutants in the vegetated areas of the roadscape, resulting in much smaller loads of pollutants in the storm water than in some previous studies.

Conclusions

Ecotoxicological evaluations of storm water including run off from rain events from urban roadscape studies clearly reveal that toxicity may or may not be detected depending upon site, storm condition and the test organism chosen. However, storm water might not be as polluted as previously reported nor may the first flush be such a widespread phenomenon as we originally expected. In this study, there was also a good correlation between pollutant load measured and the lack of toxicity. The test organisms chosen in this study are commonly used in effluent control programs in Sweden and other countries, which makes it possible to compare the results with those from other effluents. In this study, only acute toxicity tests were used and further studies using chronic toxicity tests, assays for genotoxic compounds or in situ bioassays might reveal biological effects at this site. Furthermore, most of the samples were taken in spring, summer or fall and it is possible that winter conditions might alter the constituents in the storm water and, thus, the toxicity of the samples.

Recommendations and Perspectives

Considering the complex nature of run off from urban roadscapes, it will be virtually impossible to evaluate properly the potential hazard of particular storm water and the efficiency of a particular treatment strategy from only physical and chemical characterizations of the effluent. Therefore, despite the lack of toxicity detected in this study, it is recommended that toxicity tests or other biological methods should be included in evaluations of the effects of runoff from roadscapes.

     

Evaluation of the giant reed (<Emphasis Type="Italic">Arundo donax</Emphasis>) in horizontal subsurface flow wetlands for the treatment of recirculating aquaculture system effluent

Introduction

Two emergent macrophytes, Arundo donax and Phragmites australis, were established in experimental subsurface flow, gravel-based constructed wetlands (CWs) receiving untreated recirculating aquaculture system wastewater.

Materials and methods

The hydraulic loading rate was 3.75 cm day^?1. Many of the monitored water quality parameters (biological oxygen demand [BOD], total suspended solids [TSS], total phosphorus [TP], total nitrogen [TN], total ammoniacal nitrogen [TAN], nitrate nitrogen [NO₃], and Escherichia coli) were removed efficiently by the CWs, to the extent that the CW effluent was suitable for use on human food crops grown for raw produce consumption under Victorian state regulations and also suitable for reuse within aquaculture systems.

Results and discussion

The BOD, TSS, TP, TN, TAN, and E. coli removal in the A. donax and P. australis beds was 94%, 67%, 96%, 97%, 99.6%, and effectively 100% and 95%, 87%, 95%, 98%, 99.7%, and effectively 100%, respectively, with no significant difference (p?>?0.007) in performance between the A. donax and P. australis CWs. In this study, as expected, the aboveground yield of A. donax top growth (stems + leaves) (15.0?±?3.4 kg wet weight) was considerably more than the P. australis beds (7.4?±?2.8 kg wet weight). The standing crop produced in this short (14-week) trial equates to an estimated 125 and 77 t ?ha^?1 year^?1 biomass (dry weight) for A. donax and P. australis, respectively (assuming that plant growth is similar across a 250-day (September–April) growing season and a single-cut, annual harvest).

Conclusion

The similarity of the performance of the A. donax- and P. australis-planted beds indicates that either may be used in horizontal subsurface flow wetlands treating aquaculture wastewater, although the planting of A. donax provides additional opportunities for secondary income streams through utilization of the energy-rich biomass produced.