A decision framework for possible remediation of contaminated sediments in the River Kymijoki, Finland

Background, aim, and scope  The paper describes the spatial contamination of the River Kymijoki, South-Eastern Finland, and the coastal region of the Gulf of Finland with PCDD/Fs and mercury. The findings of ecotoxicologial and human health studies are also reported, including environmental and human risk assessments. Sediments from the River Kymijoki, draining into the Gulf of Finland, have been heavily polluted by the pulp and paper industry and by chemical industries. A wood preservative, known as Ky-5, was manufactured in the upper reaches of the river between 1940 and 1984 causing severe pollution of river sediments with polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF). Moreover, the sediments have been polluted with mercury (Hg) from chlor-alkali production and the use of Hg as a slimicide in pulp and paper manufacturing. Materials and methods  An extensive sediment survey was conducted as well as sediment transport modeling, toxicity screening of sediment invertebrates, and a survey of contaminant bioaccumulation in invertebrates and fish. Studies on human exposure to PCDD/Fs and the possible effects on hypermineralization of teeth as well as an epidemiological study to reveal increased cancer risk were also conducted. An assessment of the ecological and human health risks with a null hypothesis (no remediation) was undertaken. Results  The sediment survey revealed severe contamination of river and coastal sediments with PCDD/Fs and Hg. The total volume of contaminated sediments was estimated to reach 5 × 10⁶ m³ and hot spots with extremely high concentrations (max 292,000 ng g⁻¹ or 1,060 ng I-TEQ g⁻¹ d.w.) were located immediately downstream from the pollution source (approximately 90,000 m³). Sediment contamination was accompanied by changes in benthic assemblages, but direct effects were masked by many factors. The fish showed only slightly elevated PCDD/F levels in muscle, but orders of magnitude higher in the liver compared with reference freshwater sites and the Baltic Sea. The concentrations in human fat did not reveal high human exposure in the Kymijoki area in general and was lower than in sea fishermen. The relative risk for total cancer among farmers was marginally higher (RR = 1.13) among those living close to the river, compared with farmers living further away, and the possibility of increased cancer risk cannot be ruled out. A conservative risk assessment revealed that the present probability of exceeding the WHO upper exposure limit of 4 pg WHO-TEQ kg⁻¹ d⁻¹ for PCDD/Fs and DL-PCBs was 6%. The probability of exceeding the WHO limit value of 0.23 μg kg⁻¹ d⁻¹ for methyl mercury was estimated to be notably higher at 62%. Based on these studies and the estimated risks connected with different remediation techniques a general remediation plan with cost benefit analysis was generated for several sub-regions in the river. Dredging, on-site treatment, and a close disposal of the most contaminated sediments (90,000 m³) was suggested as the first phase of the remediation. The decision regarding the start of remediation will be made during autumn 2008. Conclusions  The sediments in the River Kymijoki are heavily polluted with PCDD/Fs and mercury from earlier chlorophenol, chlor-alkali, and pulp and paper manufacturing. A continuous transport of contaminants is taking place to the Gulf of Finland in the Baltic Sea. The highly increased PCDD/F and Hg levels in river sediments pose an ecotoxicological risk to benthic fauna, to fish-eating predators and probably to human health. The risks posed by mercury exceed those from PCDD/Fs and need to be evaluated for (former) chlor-alkali sites and other mercury releasing industries as one basis for remediation decision making. Recommendations and perspectives  The studies form the basis of a risk management strategy and a plan for possible remediation of contaminated sediments currently under consideration in the Southeast Finland Regional Environment Centre. It is recommended that a detailed restoration plan for the most seriously contaminated areas should be undertaken. Based on current knowledge, the restoration of the whole river is not feasible, considering the current risk caused by the contaminated sediment in the river and the costs of an extensive restoration project. The experiences gained in the present case should be utilized in the evaluation of PCDD/F- and mercury-contaminated sites in other countries. The case demonstrates that the historic reservoirs are of contemporary relevance and should be addressed, e.g., in the national implementation plans of the Stockholm Convention. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Benefits from and threats to European treeline ecosystem services: an exploratory study of stakeholders and governance

The concept of ecosystem services (ES) is being increasingly applied in environmental governance and science. To safeguard key ES in changing and complex social–ecological systems such as treeline areas, we need to (1) map key ES in different types of treeline landscapes, (2) identify the stakeholders benefiting from and threatening ES, and (3) examine how ES could be governed more sustainably. We explore these questions in European treeline areas by using quantitative and qualitative social science techniques to analyse responses from a survey of local scientific experts in 20 altitudinal and polar treeline areas in 15 European countries. In contrast to the prevalent consideration of treeline areas as a single type of a social–ecological system, we show that European treeline areas can be divided into two types that significantly differ in the delivery of ES. Our analyses allowed us to categorize stakeholders according to their benefits from and threats to ES; “Green key players” formed the most numerous group, while smaller number of stakeholder groups was categorized as “Harmless crowd”, “Occasional stressors”, and “Risky users”. However, behaviour of stakeholders is very much site-specific. Of 595 pairs of stakeholders analysed, we found <5 EU-wide “Allies” and “Opponents”. Recommendations for improved governance include adjusting governance instruments to specific problems in divergent treeline systems and creating participatory structures where stakeholders better interact with scientists and can genuinely influence management decisions.     

Biochemical transformation of birch leaf phenolics in larvae of six species of sawflies

Summary. We investigated the biochemical transformation of individual phenolic compounds of mountain birch leaves in larvae of six birch-feeding sawfly species: Amauronematus amplus, Pristiphora alpestris, Nematus brevivalvis, Priophorus pallipes, Arge sp. and Nematus viridis by comparing the phenolic residues in larval faeces to those of their leaf diet. Partial hydrolysis of hydrolysable tannins, isomerisation of chlorogenic acid and glycosylation of flavonoid aglycones were observed in all studied species. Moreover, we found considerable among-species variation in the composition of phenolic compounds in larval faeces. In addition to foliar phenolics, seventeen non-foliar phenolic metabolites, including eight phenolic acids and nine flavonoid glycosides were detected from the faeces. Of the non-foliar phenolic acids, four were egested species-specifically and only two by all six sawfly species. We also detected differences in the ratios of chlorogenic acid isomers in the faeces of different species, which can indicate different physiological conditions in the guts of studied larvae. In addition to the qualitative differences, quantitative differences were detected in the egestion of chlorogenic acids, possible o-quinone precursors in the larvae. Detected differences, either qualitative or quantitative, could not be explained by seasonal changes in the content of compounds in the leaf diet.     

Arsenic and other toxic elemental contamination of groundwater, surface water and soil in Bangladesh and its possible effects on human health

The problems of contamination caused by arsenic (As) and other toxic metals in groundwater, surface water and soils in the Bengal basin of Bangladesh have been studied. Altogether 10 groundwater, seven surface water and 31 soil samples were collected from arsenic-affected areas and analysed chemically. The geologic and anthropogenic sources of As and other toxic metals are discussed in this paper. The chemical results show that the mean As concentrations in groundwater in the Char Ruppur (0.253mg As L^–1), Rajarampur (1.955mg As L^–1) and Shamta areas (0.996mg As L^–1) greatly exceed the WHO recommended value, which is 0.01mg As L^–1. The concentrations of As in groundwater are very high compared to those in surface water and in surface soil in the three (As-affected) areas studied. This indicates that the source of As in groundwater could be bedrock. The relatively high concentrations of Cr, Cu, Ni, Pb and Zn in surface water, compared to world typical value, are due to the solubility of metal ions, organometalic complexes, coprecipitation or co-existance with the colloidal clay fraction. In the soil, the elevated concentrations of As, Cr, Cu, Ni, Pb and Zn are due to their strong affinity to organic matter, hydrous oxides of Fe and Mn, and clay minerals.     

Impacts of a participatory approach to developing national level sustainable development indicators in Finland

The paper explores the role of a participatory approach in the outcome of the Finnish sustainable development indicator (SDI) exercise in 1998-2002. The process is analysed through three main objectives: to achieve stronger democracy, better quality of the end product and a more effective process. The analysis is further structured by a set of criteria needed for successful participation and differentiation of types of participants. The criteria comprise three main aspects: fairness, competence and social learning. In addition to the normally mentioned stakeholders (e.g. citizens and interest groups) participants also include experts and civil servants. Using the set of criteria above the participatory approach of the Finnish SDI process is then evaluated, and in the light of this evaluation the paper also discusses the specifications needed as evaluation criteria for national level policy programme processes like developing the SDIs. The results are based on documentation of the indicator task force meetings, written comments and a study of the putative end-users conducted after the publication of the indicators. The results show that the intense and broad participation of experts and civil servants increased the competence of the outcome and led to greater efficiency in working methods. However, this led to technocratic participation, absence of democratic participation and absence of social learning. Thus the ultimate goal of SDIs to contribute to achieving sustainability was not reached.     

Pedestrian behavior and exit selection in evacuation of a corridor - An experimental study

In this paper, we present an experiment whose purpose was to study evacuees’ exit selection under different behavioral objectives. The experiment was conducted in a corridor with two exits located asymmetrically. This geometry was used to make most participants face a nontrivial decision on which exit to use. We analyze the behavior on a macroscopic level using statistical methods. Our results suggest that the members of an evacuating crowd may not be able to make optimal decisions when assessing the fastest exit to evacuate. In addition, the egress time of the whole crowd turns out to be shorter when the evacuees behave egoistically instead of behaving cooperatively. This is an interesting result because many studies on real emergencies show that evacuees tend to cooperate and act altruistically.     

Risk taking and accident frequency among Finnish forestry workers

The results of previous studies on the relationship between risk taking and accidents have been contradictory. The aim of this study is to examine the relationship between risk taking and accident frequency among Finnish forestry workers. The subjects were 228 forestry workers whose risk taking was measured on a questionnaire with 25 items. The accident frequency was calculated based on both company-recorded and self-reported accidents. There were no significant relationships between risk taking and accident frequency. Even after elimination of age and work experience by partial correlations, there was no significant correlation between risk taking and accident frequency. Of the personality traits of the forestry workers, impulsiveness and neuroticism correlated significantly with risk taking but not with accident frequency. Two explanations for the failure to find significant correlation between risk taking and accident frequency are given.     

Legal requirements and wastewater discharges to Polish water bodies, 1945-2003

The postwar development of water protection legislation and wastewater discharges is poorly known for the Baltic Sea region as a whole. This article presents national efforts to govern wastewater discharges in Poland using legal tools over the twentieth century with an emphasis on the postwar period, 1945-2003. The study also attempts to evaluate how the state authority responded to changing legal demands in terms of urban and industrial wastewater discharges in the postwar period. It outlines the main changes during the socialist regime in Poland and after it regained independence. Also the implications of Poland's integration into the European Union are briefly discussed. Mathematical calculations are used to illustrate some changes in legal requirements over time.     

Multicriteria decision support in a technology competition for cleaning polluted soil in Helsinki

Due to expansion of the capital area in Finland, industrial areas are being replanned for residential and commercial use. The soil in these areas is sometimes contaminated, and must therefore be cleaned before building. In spring 1997 the City of Helsinki and the National Technology Agency of Finland declared a contract-based competition for cleaning the polluted soil of the planned Toukolanranta residential area. Nine proposals entered the competition, and the problem was to choose three best candidates for test-cleaning a small part of the region considered. The winner of the test-cleaning phase will get the contract for cleaning the whole area. The proposals were evaluated based on five criteria defined by the competition board consisting of eight experts. The finalists were chosen aided by the SMAA-2 Stochastic Multicriteria Acceptability Analysis technique. SMAA-2 is a method for analysing what kind of preferences favour each alternative. This method is particularly useful in applications, where it is difficult or impossible to obtain accurate preference information. In this application SMAA-2 was observed to suit well for choosing a small set of best alternatives with different strengths and weaknesses.