Assessing the impact of different assumptions on the size of a Mixture Assessment Factor (MAF) for chemical mixtures in surface waters using data from three recent monitoring studies.

Mixture Assessment Factors (MAFs) have been proposed in the European Union (EU) as a rapid and simple way of protecting aquatic organisms from the combined effects of unintentional chemical mixtures when regulating industrial chemicals under the REACH (EU Regulation on the registration, evaluation, authorisation, and restriction of chemicals) program. A wide range of values has been suggested for the MAF including values of 20 or larger. In this paper we performed a series of case studies using composition data from 46,546 mixtures reported in three surveys of chemicals in EU surface waters.

Occurrence of common frog (Rana temporaria) and common toad (Bufo bufo) adults and metamorphs in agricultural fields in Germany: Potential for exposure to plant protection products.

To characterize the potential for exposure of amphibian terrestrial life stages to plant protection products (PPP), we studied the occurrence and habitat use of adult and metamorph common frogs (Rana temporaria) and common toads (Bufo bufo) in an agricultural landscape in Germany. The four selected study sites were breeding ponds with approximately 80% agricultural land within a 1-km radius. Adults were monitored by radio tracking for two years, and metamorph numbers were assessed for one summer using pitfall traps alongside drift fences.

Current testing programs for pesticides adequately capture endocrine activity and adversity for protection of vertebrate wildlife.

The toxicity and ecotoxicity of pesticide active ingredients are evaluated by a number of standardized test methods using vertebrate animals. These standard test methods are required under various regulatory programs for the registration of pesticides. Over the past two decades, additional test methods have been developed with endpoints that are responsive to endocrine activity and subsequent adverse effects.

Analysis and management of herbicidal mixtures in a high-intensity agricultural landscape in Belgium.

Water bodies located in anthropogenically influenced environments, such as agricultural landscapes, may be exposed to different chemicals simultaneously or sequentially. Yet, current environmental risk assessments focus on single active substances for unintended mixtures. For 3.

Acute toxicity of pesticide mixtures to honey bees is generally additive, and well predicted by Concentration Addition.

Understanding the frequency of non-additive effects of pesticides (synergism and antagonism) is important in the context of risk assessment. The goal of this study was to investigate the prevalence of non-additive effects of pesticides to honey bees (Apis mellifera). We investigated a large set of mixtures including insecticides and fungicides of different chemical modes of action and classes.

Risk from unintentional environmental mixtures in EU surface waters is dominated by a limited number of substances.

Unintentional environmental mixtures happen when multiple chemicals co-occur in the environment. A generic mixture assessment factor (MAF), has been proposed to account for this. The MAF is a number by which safe exposure levels for single chemicals are divided to ensure protection against combined exposures to multiple chemicals.

Predicted Dermal and Dietary Exposure of Bats to Pesticides.

Wild birds and mammals that feed in agricultural habitats are potentially exposed to pesticides through various routes. The European Food Safety Authority (EFSA) recently published a statement which concluded that the current EFSA risk assessment scheme for birds and mammals does not adequately cover bats (Chiroptera). In the present study, we take a more detailed look at the EFSA statement and assumptions made regarding direct (dermal) and indirect (dietary) exposure of bats to pesticides in terms of their realism and the potential implications for risk assessment outcomes.

Critical Review of Read-Across Potential in Testing for Endocrine-Related Effects in Vertebrate Ecological Receptors.

Recent regulatory testing programs have been designed to evaluate whether a chemical has the potential to interact with the endocrine system and could cause adverse effects. Some endocrine pathways are highly conserved among vertebrates, providing a potential to extrapolate data generated for one vertebrate taxonomic group to others (i.e.

Narrow pH Range of Surface Water Bodies Receiving Pesticide Input in Europe.

Fate and toxicity of the active ingredients (AI's) of plant protection products in surface waters is often influenced by pH. Although a general range of pH values is reported in literature, an evaluation targeting aquatic ecosystems with documented AI inputs is lacking at the larger scale. Results show 95% of European surface waters (n = 3075) with a documented history of AI exposure fall within a rather narrow pH range, between 7.

Refinement of the ECETOC approach to identify endocrine disrupting properties of chemicals in ecotoxicology.

To use and implement an assessment scheme for the evaluation of endocrine disrupting properties of chemicals in ecotoxicology, the types of effect need to be agreed. Effects that merit further consideration in this context should fulfil the following three criteria: caused by an endocrine mode of action, be adverse, and be relevant at the population level to reflect the protection goal of ecotoxicological assessments. Thereafter, a comparison of effect values, regardless of the causative mechanisms, should be made, firstly to determine if endocrine toxicity generates the lowest endpoint within a taxon, and secondly if it is the lowest endpoint compared to that of other taxa living in the same compartment.

Risk assessment of endocrine active chemicals: identifying chemicals of regulatory concern.

The European regulation on plant protection products (1107/2009) (EC, 2009a), the revisions to the biocides Directive (COM[2009]267) (EC, 2009b), and the regulation concerning chemicals (Regulation (EC) No. 1907/2006 'REACH') (EC.2006) only support the marketing and use of chemical products on the basis that they do not induce endocrine disruption in humans or wildlife species.

Science based guidance for the assessment of endocrine disrupting properties of chemicals.

The European legislation on plant protection products (Regulation (EC) No. 1107/2009) and biocides (Directive 98/8/EC), as well as the regulation concerning chemicals (Regulation (EC) No. 1907/2006 'REACH') only support the marketing and use of chemical products on the basis that they do not induce endocrine disruption in humans or non-target species.

Ecotoxicological characterisation and classification of existing chemicals. Examples from the ICCA HPV initiative and comparison with other existing chemicals.

Goal, Scope And Background: In 1998, the International Council of Chemical Associations (ICCA) launched a global initiative to investigate more than 1,000 HPV chemicals (High Production Volume, > or = 1,000 t/a) within the refocused OECD HPV Chemicals Programme. Up to the OECD SIDS Initial Assessment Meeting in April 2004 (SIAM 18) 147 ICCA dossiers (ca. 230 CAS-No) have been assessed based on a harmonised data set.

Use of terrestrial model ecosystem data in environmental risk assessment for industrial chemicals, biocides and plant protection products in the EU.

Risk assessment approaches within the regulatory framework of the European Union (EU) based on single species tests were compared to those using data from terrestrial model ecosystems (TMEs). In a case study with the fungicide carbendazim, single species data led to ratios of the predicted environmental concentration (PEC) and predicted no effect concentration (PNEC) of above 1000, depending on available data and related assessment factors, indicating concern for the terrestrial environment. Considering the high degree of realism of the TME studies with multiple endpoints measured, but also residual uncertainty related to higher variability of endpoints, an assessment factor of 5 was applied on TME data.

Algal growth inhibition test: does shading of coloured substances really matter?

Coloured substances are often assumed to behave differently in the algal growth inhibition test due to shading of the algae. We have investigated EU-notifications of new substances and found no significant differences in algal test results between colours and non-colours. A modified method to differentiate between shading and toxicity is not satisfactory, because the method used to determine the shading effect is incorrect.

Statistical results and implications of the enchytraeid reproduction ringtest.

An international ringtest of the enchytraeid reproduction test (ERT) was performed by 29 laboratories, with two substances (carbendazim and 4-nitrophenol) and two test designs (NOEC and ECx). Although many participants had no previous experience in enchytraeid ecotoxicology, the majority of tests were performed accurately and fulfilled the validity criteria, demonstrating method feasibility. However, variability in control reproduction was fairly high and exceeded the proposed validity criterion of a 50% coefficient of variation in 24% of the tests.