Sources, transport and reactivity of anionic and non-ionic surfactants in several aquatic ecosystems in SW Spain: a comparative study

Presence, distribution and transport mechanisms of the four major synthetic surfactants -linear alkylbenzene sulfonates (LAS), alkyl ethoxysulfates (AES), nonylphenol ethoxylates (NPEOs) and alcohol ethoxylates (AEOs)- have been simultaneously studied in different aquatic ecosystems. Urban wastewater discharges and industrial activities were identified as the main sources for these compounds and their metabolites. LAS, AES and carboxylic metabolites remained in the dissolved form (87–99%). However, NPEOs and AEOs were mostly associated with particulate matter (65–86%), so their degradation in the water column was limited due to their lower bioavailability. It was also observed that sorption to the particulate phase was more intense for longer homologs/ethoxymers for all surfactants. With respect to surface sediments, AES levels were considerably below (<0.25 mg/kg) the values detected for LAS and NPEOs. Concentrations of AEOs, however, were occasionally higher (several tens of ppm) than those found for the rest of the target compounds in several sampling stations.     

Experimental approaches and analytical techniques for determining organic compound bound residues in soil and sediment

Research has shown that many chemicals form persistent and permanently bound residues in soils and sediments that play an important role in soil and sediment detoxification processes, long-term compound partitioning behaviour and compound bioavailability and toxicity in soil and sediment. This article reviews the methodological approaches that have been applied to determine the nature of bound residues in soil and sediment, the application of specific analytical techniques, the type of information they generate, and their relative advantages and disadvantages. It begins by defining bound residues and discussing soil-compound interactions. The application of model compound studies for elucidating specific binding interactions is reviewed along with long-term laboratory and field soil incubation experiments. The use of radiolabelled compounds, isotopically labelled compounds and combinations of both in these experiments are outlined by examples from the literature, along with sequential extraction schemes for releasing bound residues from soil, sediment and humic materials. The importance of spectroscopic methods, and particularly nuclear magnetic resonance techniques for characterising the structure of bound residues in soil and sedimentary humic substances is discussed and illustrated by examples from the literature on the subject. The process of bound residue formation is highly complex and requires further research to establish the mechanisms of bound residue formation and their subsequent environmental and toxicological fate. Much of the uncertainty regarding the elucidation of bound residue formation arises from our poor understanding of the structure of soil and sedimentary organic matter. Significant advances in our understanding of the formation and fate of bound residues will be made when we develop a deeper insight into the complex and heterogeneous structure of soil and sedimentary organic matter.     

Environmental features of two commercial surfactants widely used in soil remediation

One of the main limitations for a wider application of surfactants in soil remediation is the lack of knowledge about environmental fate and toxicity of surfactant itself especially for in situ application. Sorption behaviour, biodegradability, toxicity of parent compound and its metabolites are important processes that affect environmental fate of surfactants in site remediation applications. Tween 80 (poly(oxyethylene)(20)-sorbitane monooleate) and Aerosol MA+80 (dihexyl sodium sulfosuccinate) are surfactants that have been tested in laboratory and field scale remediation of soil and groundwater. In this work, the sorption and biodegradability of these surfactants were assessed to provide conditions and limitations for their use. The soil used in this experimentation was analysed for organic carbon content, soil bacteria, and size fraction and resulted to be a good model because is characterised by mean values for almost all considered parameters. Tween 80 showed high degree of biodegradability but a high affinity for soil matrix. Results suggest that Tween 80 could find its best application in ex situ solid phase remediation like ex situ bioremediation; its high affinity to soil could limit in situ applications. Biodegradation tests for Aerosol MA+80 show low degree of biodegradability and mineralisation. Biodegradation experiments, coupled with analysis of toxicity, could support the hypothesis that degradation of Aerosol MA+80 is not complete and leads to an accumulation of intermediates with at least the same toxicity of the parental compound. Therefore, aquifer remediation application with Aerosol MA+80 has to be conducted with necessary precautions to avoid product loss and excess surfactant should be flushed from the soil.     

Assessment of bioconcentration and secondary poisoning of surfactants

The relevance of the bioconcentration behaviour of surfactants for the secondary poisoning assessment and for the risk characterisation in the bird and mammalian food chain has been investigated. The approach used is described in the recently revised EU Technical Guidance Document for the Risk Assessment of Substances. The results demonstrate that, based on experimentally derived bioconcentration factors, environmental concentrations and effects in animals, there is a clear level of safety for both linear alkylbenzene sulphonate (LAS) and alcohol ethoxylates (AE), the most important surfactants by volume. To assess other surfactants used in detergents, a bioconcentration factor that would need to be attained for secondary poisoning to be of concern has been estimated from predicted environmental concentrations and known long-term effects data in animals. Based on the known structural similarity of these surfactants to LAS and AE and the ubiquitous nature of the enzymatic systems that are present in biotransformation processes in organisms, it is concluded that bioconcentration of these surfactants to these levels is highly unlikely. Therefore the potential for secondary poisoning effects of these surfactants is extremely low.     

The environmental fate of the primary degradation products of alkylphenol ethoxylate surfactants in recycled paper sludge.

Alkylphenol ethoxylates (APEOs) are a group of non-ionic surfactants that are degraded microbially into more lipophilic degradation products with estrogenic potential, including nonylphenol monoethoxylate (NP1EO), nonylphenol diethoxylate (NP2EO), octylphenol (4-tOP) and nonylphenol (4-NP). Nonylphenol ethoxylates are used in paper recycling plants for de-inking paper and have the potential to be released into the environment through spreading of wastewater treatment sludge for soil amendment. Three samples of recycled paper sludge were collected from farmers' fields and analyzed for concentrations of NP1EO, NP2EO, 4-NP and 4-tOP. Each sample differed in the amount of time elapsed since the sludge was placed on farmers' fields. Primary degradation products of APEOs were present at low micrograms/g concentrations in the sludge samples. Differences in the concentrations of these analytes in sludge samples indicated that APEO concentrations declined by 84% over a period of 14 weeks on farmers' fields. Changes in the chromatographic patterns of acetylated 4-NP indicated that there is a group of recalcitrant nonylphenol isomers that degrades more slowly than other isomers. These data indicate that microbial degradation may reduce the risk of environmental contamination by these compounds, but more work is required to assess the toxic potential of APEOs in sludges used for soil amendment.     

Acetochlor as a soil pollutant

Acetochlor is a widely used herbicide all over the world. Similarly to other organic pollutants, the environmental fate of the acetochlor is strongly related to its adsorption properties. Static adsorption equilibrium measurements were carried out at 25 degrees C on different types of Hungarian soils characterized by varying amounts of organic matter and pH values. Isotherms obtained under different conditions, as well as on various soils, exhibit a similar shape, thus indicating a two-step adsorption process. The plots cannot be interpreted according to the classes of isotherms suggested by Giles. The adsorption coefficients (K) were estimated from the initial slope of the curves. These values were determined not only by the type of the soil, but also by the composition of the aqueous media. The organic matter adsorption coefficients (Kom) were also calculated and they were approximately identical for soils of high organic matter. Due to the low value of the adsorption coefficients, the acetochlor is a rather mobile pollutant of the soil posing a potential danger to the aquatic environment. For soils with high organic content, the Kom values are similar to each other and, due to the significant coverage of the inorganic surfaces, the adsorption is controlled by the solute-organic substance interactions. The adsorption of weakly polar compounds, however, is remarkable even on those soils where the organic content is low. In this case, the binding is governed by the solute-inorganic surface interactions. This conclusion is nicely proved by the adsorption of the acetochlor on quartz. According to our hypothesis, the second part of the adsorption step is controlled by the solute-adsorbed solute interactions. The role of the organic matter in this region of the isotherm is probably negligible. As the organic matter content of the soils plays an important role in the acetochlor adsorption, humic substances must have a strong influence upon the transport of this compound. Experiments to obtain adsorption isotherms of further pesticides and the development of a quantitative model are in progress.     

The partitioning of alkylphenolic surfactants and polybrominated diphenyl ether flame retardants in activated sludge batch tests

Polybrominated diphenyl ethers and nonylphenol polyethoxylates have been reported to be estrogenic and may enter the aquatic environment through the discharge of treated sewage effluent. Therefore, their fate during wastewater treatment processes is an important factor in determining their environmental impact. Batch tests with activated sludge from a Husmann apparatus were used to determine the effects of physico-chemical properties and sludge characteristics on the partitioning of polybrominated diphenyl ether flame retardants and nonylphenol polyethoxylate surfactants during biological wastewater treatment. Hydrophobic compounds, those with high logK(ow) values, were sorbed more rapidly and to a greater extent to the solid phase than more soluble compounds. For these hydrophobic compounds sorption may become an increasingly important removal mechanism as sludge age and therefore solids content increase. The initial rate of partitioning was greatest for the most hydrophobic compounds but all rates diminished with time as a result of progressive saturation of sorbent binding sites, a reduction of sorbate availability and as a consequence of the system reaching equilibrium. The sorption of polybrominated diphenyl ethers fit Freundlich adsorption isotherms demonstrating generally increasing adsorption capacity and efficiency with increasing hydrophobic nature. A correlation between increasing logK(ow) and increasing organic matter content was also observed for both polybrominated diphenyl ethers and nonylphenol polyethoxylates indicating the organic content of mixed liquor will also be influential in removing compounds during wastewater treatment.     

Environmental fate of amitrole: influence of dissolved organic matter

In this study the environmental fate of amitrole in terrestrial and aquatic model ecosystems was investigated. Under aerobic conditions mineralization of amitrole is the main degradation pathway. The experiments revealed that the leaching behaviour is low in the presence or the absence of dissolved organic matter (DOM) despite the high water solubility due to a strong binding of amitrole to soil constituents. Under anaerobic conditions the addition of DOM increases the transport of amitrole in soil columns. The tests with water/sediment model ecosystems showed that the mineralization of amitrole is lower in comparison to aerobic soil experiments. Up to 80.6% of the applied 14C-labelled amitrole transfer into the sediment and about 1/3 of this amount formed bound residues, which are not extractable.     

Human population intake fractions and environmental fate factors of toxic pollutants in life cycle impact assessment

The present paper outlines an update of the fate and exposure part of the fate, exposure and effects model USES-LCA. The new fate and exposure module of USES-LCA was applied to calculate human population intake fractions and fate factors of the freshwater, marine and terrestrial environment for 3393 substances, including neutral organics, dissociating organics and inorganics, emitted to 7 different emission compartments. The human population intake fraction is on average 10(-5)-10(-8) for organics and 10(-3)-10(-4) for inorganics, depending on the emission compartment considered. Chemical-specific human population intake fractions can be 1-2.7 orders of magnitude higher or lower compared to the typical estimates. For inorganics, the human population intake fractions highly depend on the assumption that exposure via food products can be modelled with constant bioconcentration factors. The environmental fate factor is on average 10(-11)-10(-18) days m(-3) for organics and 10(-10)-10(-12) days m(-3) for inorganics, depending on the receiving environment and the emission compartment considered. Chemical-specific environmental fate factors can be 1-8 orders of magnitude higher or lower compared to the typical estimates. The largest differences between the new and old version of USES-LCA are found for emissions to air and soil. This is caused by a significant change in the structure of the air and soil compartments in the new version of USES-LCA, i.e. the distinction between rural and urban air, including rain-no rain conditions and including soil depth dependent intermedia transport.     

Including degradation products of persistent organic pollutants in a global multi-media box model

GOAL, SCOPE AND BACKGROUND: Global multi-media box models are used to calculate the fate of persistent organic chemicals in a global environment and assess long-range transport or arctic contamination. Currently, such models assume substances to degrade in one single step. In reality, however, intermediate degradation products are formed. If those degradation products have a high persistence, bioaccumulation potential and / or toxicity, they should be included in environmental fate models. The goal of this project was to gain an overview of the general importance of degradation products for environmental fate models, and to expand existing, exposure-based hazard indicators to take degradation products into account. METHODS: The environmental fate model CliMoChem was modified to simultaneously calculate a parent compound and several degradation products. The three established hazard indicators of persistence, spatial range and arctic contamination potential were extended to include degradation products. Five well-known pesticides were selected as example chemicals. For those substances, degradation pathways were calculated with CATABOL, and partition coefficients and half-lives were compiled from literature. RESULTS: Including degradation products yields a joint persistence value that is significantly higher than the persistence of the parent compound alone: in the case of heptachlor an increase of the persistence by a factor of 58 can be observed. For other substances, the increase is much smaller (4% for alpha-HCH). The spatial range and the arctic contamination potential (ACP) can increase significantly, too: for 2,4-D and heptachlor, an increase by a factor of 2.4 and 3.5 is seen for the spatial range. However, an important increase of the persistence does not always lead to a corresponding increase in the spatial range: the spatial range of aldrin increases by less than 50%, although the persistence increases by a factor of 20 if the degradation products are included in the assessment. Finally, the arctic contamination potential can increase by a factor of more than 100 in some cases. DISCUSSION: Influences of parent compounds and degradation products on persistence, spatial range and ACP are discussed. Joint persistence and joint ACP reflect similar characteristics of the total environmental exposure of a substance family (i.e., parent compound and all its degradation products). CONCLUSIONS: The present work emphasizes the importance of degradation products for exposure-based hazard indicators. It shows that the hazard of some substances is underestimated if the degradation products of these substances are not included in the assessment. The selected hazard indicators are useful to assess the importance of degradation products. RECOMMENDATIONS AND PERSPECTIVES: It is suggested that degradation products be included in hazard assessments to gain a more accurate insight into the environmental hazard of chemicals. The findings of this project could also be combined with information on the toxicity of degradation products. This would provide further insight into the importance of degradation products for environmental risk assessments.     

双酚A和典型类固醇环境激素迁移转化研究进展

近年来有关环境激素污染的认知、研究与防治已经开始受到全球的重视,其中双酚A(BPA)和类固醇是环境中检出频率较高的几种环境激素.国外有关BPA和类固醇环境激素的调查和其迁移转化的研究已经广泛展开,但我国仍处于起步阶段.综述了国内外BPA和两种典型类固醇激素17β-雌二醇(E2)和17α-乙炔基雌二醇(EE2)的研究进展,介绍了其基本性质、用途、危害、环境中浓度和其迁移转化规律;指出为了阐明BPA、E2和EE2在环境中危害,有关其吸附、生物降解和光降解等迁移转化规律,及各迁移转化过程之间协同作用与相互影响的研究还有待于进一步深入.     

Volatility of TCDD and PCB from soil

Volatilisation fluxes of 2,3,7,8-tetrachlorodibenzodioxin and Aroclors 1242, 1254 and 1260 were estimated from the model of Jury et.al., developed for compounds with similar physical properties. The influence of soil water content, soil organic matter and water evaporation was investigated. Increasing soil organic matter decreased the volatilisation flux of all four chemicals. Water evaporation was accompanied by increased fluxes, implying that the chemicals were susceptible to wicking. The trends observed were in qualitative agreement with field and laboratory studies. The predicted fluxes serve as a basis for comparing their volatilisation behaviour against pesticides and other homologues, and for the construction of models describing the environmental fate of these compounds.     

Fate and transport of monoterpenes through soils. Part I. Prediction of temperature dependent soil fate model input-parameters

Monoterpenes are C10H(n)O(n') compounds of natural origin and are potentially environmentally safe substitutes for traditional pesticides. Still, an assessment of their environmental behaviour is required. As a first step in a theoretical study focussing on monoterpenes applied as pesticides to terrestrial environments, soil fate model input-parameters were determined for 20 monoterpenes with widely different structural characteristics. Input-parameters are the water solubility (S(W)), vapour pressure (P), n-octanol-water partition coefficient (K(OW)), atmospheric air and bulk water diffusion coefficients (D(A)air and D(W)water), first order biodegradation rate constants (k), and their temperature dependence. Values for these parameters were estimated or taken from previous experimental work. The quality of the estimations was discussed by focussing on their statistics and by comparison with available experimental data. From these properties, the air-water partition coefficient (K(AW), Henry's Law constant), the interface-water partition coefficient (K(IW)) and the organic matter-water partition coefficient (K(OM)) could be estimated with varying levels of accuracy. In general, little experimental data turned out to be available on biodegradation rate constants and on the temperature dependence of physico-chemical parameters.     

Priority assessment of toxic substances in life cycle assessment. Part I: calculation of toxicity potentials for 181 substances with the nested multi-media fate, exposure and effects model USES-LCA

Toxicity potentials are standard values used in life cycle assessment (LCA) to enable a comparison of toxic impacts between substances. In most cases, toxicity potentials are calculated with multi-media fate models. Until now, unrealistic system settings were used for these calculations. The present paper outlines an improved model to calculate toxicity potentials: the global nested multi-media fate, exposure and effects model USES-LCA. It is based on the Uniform System for the Evaluation of Substances 2.0 (USES 2.0). USES-LCA was used to calculate for 181 substances toxicity potentials for the six impact categories freshwater aquatic ecotoxicity, marine aquatic ecotoxicity, freshwater sediment ecotoxicity, marine sediment ecotoxicity, terrestrial ecotoxicity and human toxicity, after initial emission to the compartments air, freshwater, seawater, industrial soil and agricultural soil, respectively. Differences of several orders of magnitude were found between the new toxicity potentials and those calculated previously.     

Importance of considering pesticide stereoisomerism--proposal of a scheme to apply Directive 91/414/EEC framework to pesticide active substances manufactured as isomeric mixtures

An important gap has been detected in the application of the European framework for the evaluation of pesticide active substances constituted by enantiomeric and other kind of stereoisomeric mixtures. Up to date, little attention has been paid to the different biological properties of these compounds. Considering efficacy, toxicity, environmental fate and behaviour and ecotoxicity of separated isomers is necessary to fulfil Directive 91/414/EEC objectives of health and environment protection. Here, a critical review of this question for pesticide active substances is presented. An evaluative scheme for considering this question in the framework of Directive 91/414/EEC is also proposed.     

Simultaneous transport of parent and daughter compounds in aquifers with linear first-order sorption kinetics

In soils, daughter compounds may be generated from a parent compound by microbial metabolism, chemical reactions, radioactive decay, or other mechanisms. These daughter compounds are also acted upon by soil physical, chemical and biological processes. A system often referred to as a cascade or chain of compounds system results. While a great deal of attention has been given to this problem with the linear equilibrium assumption applied uniformly to all transport and reacting compounds, little attention has been given to the simultaneous transport and fate of a parent-daughter chain with a first-order rate assumed for the adsorption-desorption kinetics of each compound and with the soil partitioned into three sorption classes.A general one-dimensional cascade or chain model for the simultaneous transport of parent and daughter compounds in sorbing, homogeneous, water table aquifers is presented. The model is based on an advective-dispersive mass accounting formulation for both compounds and includes: (a) first-order rate of conversion of parent to daughter; (2) first-order rates of loss of either parent or daughter or both due to metabolism, chemical reaction and/or irreversible processes; (3) partitioning of the aquifer material into three sorption classes, namely mildly sorbing, strongly sorbing and organic matter; (4) linear first-order kinetic rules for adsorption and desorption operating on each of the sorbing soil fractions for each compound; (5) constantly emitting sources of rectangular shape of parent compound; and (6) mass accounting boundary conditions; and a tailorable initial distribution on [0, ∞). Mathematical analysis yields a coupled, linear system of equations including two transport and fate equations, initial and boundary data, and six kinetic rules, namely three each for parent and daughter compound. A numerical scheme for solving the system of equations was developed using readily available procedures since analytical solutions could not be found. Solutions for scenarios based on leaking underground sources are presented.     

Part V—sorption of pharmaceuticals and personal care products

Background, aim, and scope  Pharmaceuticals and personal care products (PPCPs) including antibiotics, endocrine-disrupting chemicals, and veterinary pharmaceuticals are emerging pollutants, and their environmental risk was not emphasized until a decade ago. These compounds have been reported to cause adverse impacts on wildlife and human. However, compared to the studies on hydrophobic organic contaminants (HOCs) whose sorption characteristics is reviewed in Part IV of this review series, information on PPCPs is very limited. Thus, a summary of recent research progress on PPCP sorption in soils or sediments is necessary to clarify research requirements and directions. Main features  We reviewed the research progress on PPCP sorption in soils or sediments highlighting PPCP sorption different from that of HOCs. Special function of humic substances (HSs) on PPCP behavior is summarized according to several features of PPCP–soil or sediment interaction. In addition, we discussed the behavior of xenobiotic chemicals in a three-phase system (dissolved organic matter (DOM)–mineral–water). The complexity of three-phase systems was also discussed. Results  Nonideal sorption of PPCPs in soils or sediments is generally reported, and PPCP sorption behavior is relatively a more complicated process compared to HOC sorption, such as the contribution of inorganic fractions, fast degradation and metabolite sorption, and species-specific sorption mechanism. Thus, mechanistic studies are urgently needed for a better understanding of their environmental risk and for pollution control. Discussion  Recent research progress on nonideal sorption has not been incorporated into fate modeling of xenobiotic chemicals. A major reason is the complexity of the three-phase system. First of all, lack of knowledge in describing DOM fractionation after adsorption by mineral particles is one of the major restrictions for an accurate prediction of xenobiotic chemical behavior in the presence of DOM. Secondly, no explicit mathematical relationship between HS chemical–physical properties, and their sorption characteristics has been proposed. Last but not least, nonlinear interactions could exponentially increase the complexity and uncertainties of environmental fate models for xenobiotics. Discussion on proper simplification of fate modeling in the framework of nonlinear interactions is still unavailable. Conclusions  Although the methodologies and concepts for studying HOC environmental fate could be adopted for PPCP study, their differences should be highly understood. Prediction of PPCP environmental behavior needs to combine contributions from various fractions of soils or sediments and the sorption of their metabolites and different species. Recommendations and perspectives  More detailed studies on PPCP sorption in separated soil or sediment fractions are needed in order to propose a model predicting PPCP sorption in soils or sediments based on soil or sediment properties. The information on sorption of PPCP metabolites and species and the competition between them is still not enough to be incorporated into any predictive models.     

Selection of surfactant in remediation of DDT-contaminated soil by comparison of surfactant effectiveness

With an aim to select the most appropriate surfactant for remediation of DDT-contaminated soil, the performance of nonionic surfactants Tween80, TX-100, and Brij35 and one anionic surfactant sodium dodecyl benzene sulfonate (SDBS) in enhancement of DDT water solubility and desorption of DDT from contaminated soil and their adsorption onto soil and ecotoxicities were investigated in this study. Tween80 had the highest solubilizing and soil-washing ability for DDT among the four experimental surfactants. The adsorption loss of surfactants onto soil followed the order of TX-100 > Tween80 > Brij35 > SDBS. The ecotoxicity of Tween80 to ryegrass (Lolium perenne L.) was lowest. The overall performance considering about the above four aspects suggested that Tween80 should be selected for the remediation of DDT-contaminated soil, because Tween80 had the greatest solubilizing and soil-washing ability for DDT, less adsorption loss onto soil, and the lowest ecotoxicity in this experiment.     

Fragrances in the Environment: Pleasant odours for nature? (9 pp)

Goal, Scope and Background Fragrance preparations or perfumes are used in an increasing variety of applications, as for example washing, cleansing, personal care products, consumer goods or in applications to modify indoor air. However, up to now, little is known to the general or scientific public about their chemical identity and the use pattern of single substances, not even for high production volume chemicals. Some toxicological data are published for a comparatively small number of substances with a focus on sensitisation and dermal effects, while other effects are neglected. Information on ecotoxicity and environmental fate are rare, especially for long-term exposure. Data for a detailed hazard and risk analysis are available in exceptional cases only. According to the current legal situation, fragrance industry is self-regulated, which means that pre-market risk evaluation is not required for most fragrances. Odour and the ability to smell play a major role for wildlife for all taxonomic groups. Reproductive and social behaviour, defence, communication and orientation depend on volatile compounds which can be identical to those used in fragrance preparations. Our interdisciplinary approach leads to the question of whether and, if so, to what extent anthropogenic fragrances may influence life and reproduction of organisms in the environment. Main Features Information from literature on use, exposure and biological effects was combined to analyse the state of knowledge. Following an overview of the amounts of fragrances used in different consumer products and their release into the environment, the roles of odours in nature are shown for a selection of compounds. Existing regulation was analysed to describe the data basis for environmental risk evaluation. Finally, recommendations for further action are derived from these findings. Results Three main results were elaborated: First, fragrance substances are continuously discharged in large amounts into the environment, especially via the waste water. Second, there are some indications of negative effects on human health or the environment, although the data basis is very thin due to the self regulation of the fragrance industry and the regulatory situation of fragrance substances. Third, many odoriferous substances used by man are identical to those which are signal substances of environmental organisms at very low concentrations, thus giving rise to specific mode of actions in the ecosystem. Recommendations For the adequate risk assessments of fragrances, test results on their unspecific as well as their specific effects as signal substances are needed. This would imply prioritisation methods and development of useful test methods for specific endpoints for appropriate risk assessments. Before a comprehensive testing and evaluation of results has been finished, a minimization of exposure should be envisaged. Eco-labelling of products containing acceptable fragrance ingredients could be a first step and provide consumers with the respective information. Transparency concerning the fragrance ingredients used and their biological potency will help to build up confidence between producers and consumers. Conclusions and Perspectives The interdisciplinary approach, bringing together chemical, biological, toxicological and ecotoxicological data with information provided by manufacturers and with legal and consumer aspects, offers new insights into the field of fragrance substances used in consumer products. The amounts and application fields of fragrance substances increases while fate and effects in the environment are hardly known. The current legal situation is not suited to elucidate the effects of fragrances on human health and the environment sufficiently, especially as it was shown that fragrances may play a considerable role in the ecosystem on the behaviour of organisms. According to the precautionary principle, the lack of knowledge should best be tackled by reducing exposure, especially for compounds such as fragrance substances where no ethical reasons object a substitution by less hazardous chemicals. ESS-Submission Editor: Dr. Thomas Knacker (th-knacker@ect.de)