Eric M. J. Verbruggen

Common implementation strategy for the water framework directive (2000/60/EC)

This Technical Guidance Document on Biota Monitoring (the Implementation of EQSbiota) aims to facilitate the implementation of environmental quality standards (EQS) in biota under the Water Framework Directive by addressing in particular the sampling strategies appropriate for monitoring programmes designed to assess compliance with biota EQS. It is Guidance Document No. 32 in the series of guidance documents prepared to support the Common Implementation Strategy (CIS) for the Water Framework Directive. It elaborates extensively on the content of Guidance Document No. 25 on Chemical Monitoring in Sediment and Biota under the Water Framework Directive, and is complemented by Guidance Document No. 33, the Technical Guidance Document on Analytical Methods for Biota Monitoring. Guidance Documents 32 and 33 together address the requirement for guidance on biota monitoring mentioned in Article 3(8a) of Directive 2008/105/EC as amended by Directive 2013/39/EU. The original Directive 2008/105/EC included biota standards for mercury, hexachlorobenzene and hexachlorobutadiene. In Directive 2013/39/EU, biota EQS were introduced for three other existing priority substances (fluoranthene, polyaromatic hydrocarbons and brominated diphenylethers), and set for four new priority substances (dicofol, perfluorooctane sulfonic acid and its derivatives, hexabromocyclododecane, and heptachlor/heptachlor epoxide). This guidance document takes into account the fact that trend monitoring in sediment and/or biota is required for several other priority substances as specified in Article 3(6), and indicates how trend monitoring data can be used to check compliance with biota EQS, but does not elaborate on trend monitoring as such. This document constitutes guidance and Member States are therefore not legally required to follow the recommendations contained in it. Member States are, however, required to use methods compliant with the requirements of the Environmental Quality Standards Directive 2008/105/EC and the Quality Assurance/Quality Control Directive 2009/90/EC.

Ecotoxicological environmental risk limits for total petroleum hydrocarbons on the basis of internal lipid concentrations

A method is described for deriving ecotoxicological environmental risk limits (ERLs) for total petroleum hydrocarbons (TPH). Toxicity data for two oil types (light and heavy) to benthic organisms and corresponding estimated internal lipid concentrations, calculated by equilibrium partitioning, are used as a measure of toxicity by narcosis. It is assumed that uptake by organisms takes place from the aqueous phase, and for partitioning, both oil droplets or coating and organic carbon of sediment are taken into account. To distinguish between the different fractions of TPH, the method used is based on a fraction analysis approach in which aliphatic and aromatic compounds are regarded separately and both are further divided into different fractions. A toxic unit approach is applied to these fractions to take additivity into account. Lethality of the lighter oil type (internal concentration 28-204 mmol/Llipid) was in good agreement with data on internal concentrations retrieved from the literature. For the heavier oil type the observed toxicity was slightly higher and can probably be attributed to physical soiling of the organisms by oil or oxygen depletion due to biodegradation of the oil. For deriving ERLs, chronic endpoints are considered. The most sensitive chronic endpoints appear to be similar for both types of oil. The distribution of estimated total internal concentrations for chronic endpoints (1.38-149 mmol/Llipid) is used as a basis for the ERLs. The resulting ERLs for the mixture of TPH are comparable with ERLs for single compounds.

Biomimetic extraction as a tool to identify chemicals with high bioconcentration potential : An illustration by two fragrances in sewage treatment plant effluents and surface waters

The Empore disk biomimetic extraction procedure is a method to estimate total body residues (TBR est ) in biota after exposure to complex mixtures of organic chemicals in water. Except for highly hydrophobic compounds, the extraction procedure is nondepletive by using an excess of water. Therefore, it is a selective extraction process of the bioavailable fraction of compounds. The extent, to which compounds are extracted, depends on their hydrophobicity. Consequently, compounds that only have a minor contribution to the total amount in exhaustive extracts can become very prominent in the biomimetic extracts. Bioconcentration is also a process that depends primarily on hydrophobicity. In this study the method is applied to selectively focus on compounds with a high bioconcentration potential. This feature is illustrated by data on two fragrances (HHCB and AHTN) in effluents of municipal sewage treatment plants and several types of surface water. Although estimated aqueous concentrations of both AHTN and HHCB ranged from about only 1 ng/L in clean surface water to 500 ng/L in the effluents of sewage treatment plants, the contribution of these two compounds together to the total amount of extracted compounds varied from 1 to 23% for surface waters and from 5 to 22% for effluents.

Physicochemical Properties of Higher Nonaromatic Hydrocarbons: A Literature Study

Few data are available on the behavior of higher aliphatic hydrocarbons in the environment and especially in relation to hydrophobicity. Sorption to soil and bioconcentration by aquatic organisms are examples of processes that can be estimated from hydrophobicity parameters, such as aqueous solubility and octanol-water partition coefficient. A literature study was carried out on these physicochemical properties of aliphatic hydrocarbons containing ten or more carbon atoms. In general, very few experimental data were found, probably as a consequence of the fact that these parameters are very difficult to determine for these compounds. Reliable data on hydrophobicity parameters, for example, were not found for n-alkanes higher than tridecane.

Hydrophobicity of complex organic mixtures

Hydrophobicity is an important property in risk assessment of chemicals. A group parameter that reflects the hydrophobicity of technical mixtures is not yet available. However, many substances are complex organic mixtures, for which it is practically impossible to determine each component separately. An experimental procedure to measure the hydrophobicity of organic mixtures without knowledge of the individual components was developed and tested for a mixture of benzene and twelve chlorobenzenes. This procedure is based on separation of the mixture into fractions of increasing hydrophobicity by reversed-phase HPLC, after which the total molar concentration in each fraction is determined by vapour pressure osmometry. The obtained information on hydrophobicity can be used for assessing bioaccumulation and sediment sorption after emission of the mixture to water has occurred.