DIOXIN 2004

Ohne Zusammenfassung     

The Water Framework Directive: stakeholder preferences and catchment management strategies--are they reconcilable?

The key objective of the European Water Framework Directive (WFD) is to promote sustainable water use by protecting water resources. Here, we investigate how the economic consequences of a set of water management regulations is received by a group of stakeholders in the R?nne? catchment. We explore three themes from an economic point of view: i) perceived causes of eutrophication, ii) preferences regarding water use, and iii) the extent to which the polluter-pays principle should be applied. There is a common understanding about the intentions in the WFD to enhance cost-effective water use. All stakeholder groups largely share a similar picture of the causes of water quality deterioration. However, there is not one cost-effective and fair solution. Several mixes of remedial measures within the same catchment are possible, depending on the scale of action. Despite potential economic gains from cooperation between sectors, the participants regard the individual polluter-pays principle as the most feasible mode of funding for remedial programs, supported by subsidies. There is little demand for more market institutions (emission fees, tradable emission permits). The stakeholders have a conservative view of water management, i.e. they accept the present combination of regulations and economic incentives, and they are fully aware of the complexity of the issue. In general, the WFD recommendations for the calculation of cost-effective abatement strategies seem to imply an underestimation of the value of external effects in the decision-making process.     

Occurrence of UV filter compounds from sunscreens in surface waters: regional mass balance in two Swiss lakes

Consumer care products often contain UV filters, organic compounds which absorb ultraviolet light. These compounds may enter surface waters directly (when released from the skin during swimming and bathing) or indirectly via wastewater treatment plants (when released during showering or washed from textiles). Predicted and measured UV filter concentrations were compared in a regional mass balance study for two Swiss lakes: Lake Zurich, a typical midland lake which is also an important drinking water resource, and Hüttnersee, a small bathing lake. Both lakes are extensively used for recreational activities and considerable direct input of UV filters is thus expected. This input was estimated from the number of visitors at swimming areas around the lakes and a survey of the usage of sunscreen products among these visitors. Possible additional indirect input via wastewater treatment plants was not considered in this study. The quantitatively most important UV filters, as indicated by the survey data, ethylhexyl methoxycinnamate, octocrylene, 4-methylbenzylidene camphor, butyl methoxydibenzoylmethane, and benzophenone-3, all lipophilic compounds, were selected for analysis by gas chromatography-mass spectrometry. Concentrations of individual UV filters in water from Lake Zurich were low, ranging from <2 ng l(-1) (detection limit) to 29 ng l(-1), and somewhat higher at Hüttnersee, ranging from <2 to 125 ng l(-1), with the highest concentrations found in summer, consistent with direct inputs to the lakes during this time. The concentrations were clearly lower than predicted from input estimates based on the surveys. This may be in part due to (i) an overestimation of these inputs (e.g. less than the 50% wash-off of UV filters assumed to occur during swimming), and (ii) some removal of these compounds from the lakes by degradation and/or sorption/sedimentation. UV filters were also detected in semipermeable membrane devices (SPMDs) deployed at Lake Zurich and Greifensee, another midland lake, at concentrations of 80-950 ng SPMD(-1), confirming the presence of the compounds in surface waters and indicating a certain potential for bioaccumulation. SPMD-derived water concentrations were in the range of 1-10 ng l(-1) and thus corresponded well with those determined in water directly. No UV filters were detected above blank levels in SPMDs deployed at a remote mountain lake used for background measurements.     

The effect of particle size reduction by grinding on subsampling variance for explosives residues in soil

Efforts to characterize the surface soil contamination on military training ranges have been compromised by the inability to obtain representative subsamples of soils submitted to analytical laboratories for determination of explosives residues. Two factors affecting subsampling error for explosives residues were examined using soils collected from hand grenade and anti-tank ranges. These factors were increased subsample size and particle size reduction prior to subsampling of soils. Increasing the subsample size from 2 to 50 g did not reduce the soil subsampling error because of the extreme heterogeneous distribution of the solid contaminants. Alternatively, particle size reduction by machine grinding on a ring mill reduced subsampling error to less than 10% relative standard deviation for replicate analyses using 10-g subsamples.     

Size-dependent behavior of tuna in an array of fish aggregating devices (FADs)

Several lines of evidence indicate that aggregations of yellowfin tuna associated with floating objects are more frequently composed of small animals than larger ones. Also, the diet of small yellowfin tuna caught at anchored fish aggregating devices (FADs) around Oahu, Hawaii, was found to shift quite rapidly when these fish reached approximately 50 cm FL. In order to test for ontogenetic changes in aggregation behavior, we tagged and released two distinct size classes of yellowfin tuna in an array of anchored FADs around Oahu, Hawaii. Twenty-four yellowfin tuna 30–39 cm FL and 16 yellowfin tuna 63–83 cm FL were tagged with acoustic transmitters and released near anchored FADs equipped with automated acoustic receivers. Fish in the smaller size class stayed about 2.5 times longer at individual FADs than the larger fish (mean 4.05 days vs. 1.65 days) and displayed larger horizontal movements within the array. However, the durations of unassociated phases, residence times in the entire FAD array, percentage of time spent associated with FADs and numbers of movements between FADs did not show any difference between the two size groups. The observed size-dependent behavior is discussed in terms of physiological abilities, diet segregation and anti-predator behavior.     

Limits of Concern: suggestions for the operationalisation of a concept to determine the relevance of adverse effects in the ERA of GMOs

Background

The European Food Safety Authority proposed a concept for the environmental risk assessment of genetically modified plants in the EU that is based on the definition of thresholds for the acceptability of potential adverse effects on the environment. This concept, called Limits of Concern (LoC), needs to be further refined to be implemented in the environmental risk assessment of genetically modified organisms.

Methods

We analyse and discuss how LoC can be defined for the environmental risk assessment for three different types of genetically modified plants. We outline protection goals relevant to the genetically modified plants in question and discuss existing concepts and suggestions for acceptability thresholds from the environmental risk assessment of different regulatory areas. We make specific recommendations for the setting and use of LoC for each type of genetically modified plant.

Results

The LoC concept can be suitably applied for the environmental risk assessment of genetically modified organisms, if the different protection goals in agro-environments are specifically considered. Not only biodiversity protection goals but also agricultural protection goals need to be addressed. The different ecosystem services provided by weeds inside and outside agricultural fields have to be considered for genetically modified herbicide-tolerant crops. Exposure-based LoCs are suggested based on knowledge about dose–effect relationships between maize pollen and non-target Lepidoptera for insect-resistant maize. Due to the long-term nature of biological processes such as spread and establishment, LoCs for genetically modified oilseed rape should be defined for the presence of the genetically modified plant or its genetically modified traits in relevant protection goals.

Conclusions

When setting LoCs, the focus should be on protection goals which are possibly affected. Potential overlaps of the LoC concept with the ecosystem service concept have to be clarified to harmonise protection levels in the agro-environment for different stressors. If additional impacts on agro-biodiversity resulting from the cultivation of genetically modified plants are to be avoided, then high protection levels and low thresholds for acceptable effects (i.e. LoC) should be set.

     

Exploring the Potential of Dutch Pig Farmers and Urban-Citizens to Learn Through Frame Reflection

The Dutch pig husbandry has become a topic of public debate. One underlying cause is that pig farmers and urban-citizens have different perspectives and underlying norms, values and truths on pig husbandry and animal welfare. One way of dealing with such conflicts involves a learning process in which a shared vision is developed. A prerequisite for this process is that both parties become aware of their own fixed patterns of thoughts, actions, and blind spots. Therefore, we conducted five homogeneous focus groups consisting of either urban-citizens or pig farmers. The first part of the sessions aimed to make the participants aware of their own perspectives and underlying norms and values concerning animal welfare, farm practices or consumer behavior. Then, by the use of role-play and film fragments showing the perspectives of the other party, we aimed to stimulate frame reflection. The farmers maintained their own perspective and defended their practices. They denied the perspective of the urban-citizens by portraying them as ignorant of the “factual” farm practices. They proposed the use of one-way information, but our results indicate that this is likely to fail as a strategy to support or restore public acceptance. Our case shows hardy any consensus regarding the relevance of the facts at stake and a very limited amount of shared values. However, the shared love for animals together with the recognition by the urban-citizens of the inescapable dilemma for farmers to adopt a use-framing towards animals might provide an opening for further learning strategies.     

A multiobjective optimization framework for multicontaminant industrial water network design

The optimal design of multicontaminant industrial water networks according to several objectives is carried out in this paper. The general formulation of the water allocation problem (WAP) is given as a set of nonlinear equations with binary variables representing the presence of interconnections in the network. For optimization purposes, three antagonist objectives are considered: F(1), the freshwater flow-rate at the network entrance, F(2), the water flow-rate at inlet of regeneration units, and F(3), the number of interconnections in the network. The multiobjective problem is solved via a lexicographic strategy, where a mixed-integer nonlinear programming (MINLP) procedure is used at each step. The approach is illustrated by a numerical example taken from the literature involving five processes, one regeneration unit and three contaminants. The set of potential network solutions is provided in the form of a Pareto front. Finally, the strategy for choosing the best network solution among those given by Pareto fronts is presented. This Multiple Criteria Decision Making (MCDM) problem is tackled by means of two approaches: a classical TOPSIS analysis is first implemented and then an innovative strategy based on the global equivalent cost (GEC) in freshwater that turns out to be more efficient for choosing a good network according to a practical point of view.