Objectives

Objectives

The COMPRENDO programme will address environment and human health aspects simultaneously by using an interdisciplinary and comparative phylogenetic approach and has the following scientific and technical objectives:

• To assess human exposure to AACs in all participating European partner countries by market basket analyses of food products (identification of background concentrations in human food) and a parallel determination of residues in human samples (blood, urine, placenta) in a highly contaminated and a reference region; to assess the exposure of wildlife populations to AACs and to characterise their effects in highly contaminated and reference regions

• To assess the potential vulnerability of representative aquatic wildlife groups (both invertebrates and vertebrates) and of humans (by using human cell lines, tissues and rodent models) to AACs by determining the impact of model compounds at environmentally relevant concentrations/doses and to identify sensitive wildlife species, critical stages of exposure and easily measurable (genetical, biochemical, physiological, histological, morphological) endpoints which can be used to determine whether pure substances or mixtures adversely affect communities in ecosystems or human populations.

• To assess common principles of the action of AACs in the analysed systematic groups (including man) so that new, sensitive, and specific animal models for extrapolation to human health can be developed.

• To develop laboratory cultures for suitable aquatic invertebrates and establish their base line endocrinology for use in risk assessment of AACs and further EDCs.

• To develop a molecular screen (array) for genes controlling development, sexual differentiation and reproduction in different vertebrate and invertebrate taxa and to quantify the effects of AACs on the expression of the target sequences.

• To evaluate the risk originating from AACs to wildlife and human populations in Europe.

Objective 1

To assess human exposure to AACs in all participating European partner countries by market basket analyses (identification of background concentrations in human food) and a parallel determination of residues in human samples (blood, urine, placenta) in a highly contaminated and a reference region; to assess the exposure of wildlife populations to AACs and to characterise their effects in highly contaminated and reference regions.

Different work packages are aimed to provide an assessment of the exposure to hormone-mimicking compounds with androgenic or antiandrogenic activity in human populations across Europe and also for aquatic wildlife species in a highly contaminated and a reference area. Due to the nature of the compounds under investigation and their broad usage as industrial chemicals and pesticides it can be assumed that humans are primarily exposed to these AACs via their food. Consequently, main emphasis for the human exposure analyses will be laid on the determination of AAC residues in representative human food samples, obtained as market basket samples in all participating European countries. Additionally, the residues of the same compounds will be determined in body fluids and tissues of a human population from a highly contaminated European region with comparably low environmental standards and a second population from a more or less uncontaminated reference area. For this purpose, different sub-groups, defined by age, gender and occupation will be considered. The sampling of environmental matrices will include sediments and aquatic organisms representing different trophic levels and systematic groups. This allows to assess not only the exposure to, and transfer of these compounds from abiotic matrices into the biota but also to analyse species- or group-specific differences and a potential bioaccumulation across the aquatic food chain. Chemical analyses of the compounds under investigation in these different samples in three independent laboratories of the consortium considering state of the art analytical techniques with quality assurance and quality control measures will be included.

Objective 2

To assess the potential vulnerability of representative aquatic wildlife groups and humans to AACs by determining the impact of model compounds at environmentally relevant concentrations/doses and to identify sensitive wildlife species, critical stages of exposure and easily measurable endpoints which can be used to determine whether substances or mixtures adversely affect communities in ecosystems or human populations.

The aim is to provide an assessment of the effects of a number of AACs in both, single compound exposure experiments at environmentally relevant concentrations and tests with complex mixtures of different compounds provided by the environmental samples. For this approach a wide range of different human-relevant test models, like human cell lines (e.g., MCF-7, SK-BR-3, LNCaP-FGC, JEG-3), human tissues (placenta, fibroblasts, gonads, liver) and rodents (Wistar rats, Rattus norvegicus), and of a wide variety of representative taxa important for the functioning of aquatic ecosystems will be used, like amphibia (Xenopus laevis), fish (Rutilus rutilus, Danio rerio, Pimephales promelas), echinoderms (Antedon mediterranea, Paracentrotus lividus), crustaceans (Hyalella azteca, Acartia tonsa) and molluscs (Marisa cornuarietis, Potamopyrgus antipodarum). We intend to investigate the effects of AACs and complex environmental samples at different levels of biological integration (from molecules to gross morphological alterations). For this work, we have access to exposure facilities in all laboratories which will cooperate. Wherever possible the considered models will be exposed to identical concentrations to enable a direct comparison of the sensitivities of the different animal groups and test systems to specific compounds / mixtures. The toxicological endpoints assigned to different biological integration levels will be analysed (identification of critical stages and of suitable morphological endpoints), (histopathological investigations), (hormone titres and comparative receptor characterisation), (biochemical markers). Dose- or concentration-response analyses will be performed for all test systems and compounds.

Objective 3

To assess common principles of the action of AACs in the analysed systematic groups (including man) so that new, sensitive, and specific animal models for extrapolation to human health can be developed.

To date, by far the greatest attention to endocrine activity of environmental chemicals has been focussed on estrogens. It is well known however, that there are chemicals discharged into the environment that have a variety of other endocrine activities and many of these chemicals end up in European aquatic ecosystems. Many of the compounds suspected as xeno-androgens or -antiandrogens are high production volume (HPV) chemicals with a wide usage as e.g. plastic stabilisers or agricultural pesticides (especially fungicides). For these compounds, also a human exposure and therefore a negative impact on human health is likely, either by the ingestion of contaminated food or additionally by an occupational exposure. It is the aim to elucidate common principles of the action of AACs in the different biological taxa considered within the COMPRENDO programme. This will include the evaluation of similarities and differences in the androgen receptors as well as in the biosynthesis, physiological role, and metabolism of endogenous androgens in the different species. Based on this evaluation, the potential of the different vertebrate and invertebrate species under investigation as new animal models for extrapolation on human health will be characterised.