101 research outputs found

    Endocrine disruption in the Scheldt estuary distribution, exposure and effects (ENDIS-RISKS). Final report

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    ENDIS-RISKS is a multidisciplinary, research project conducted by five institutes. This project aimed to assess the distribution, exposure and effects of endocrine disruptors in the Scheldt estuary, with specific attention to invertebrates. The Scheldt estuary is known to be one of the most polluted estuaries in the world. The industrial areas of Ghent and Antwerp are to a large extent responsible for this pollution. To achieve these goals detailed knowledge of the distribution and long-term effects of these substances is needed. This information is crucial for the development of future-oriented policy measures at the national and European level. The project can be divided into four different research phases. In Phase I the occurance and distribution of endocrine disrupting substances in the Scheldt estuary was studied. Water, sediment, suspended solids and biota were sampled 3 times a year for a period of 4 years (2002-2006). In all these matrices, 7 groups of chemicals were analysed: estrogens, pesticides, phthalates, organotins, polyaromatic components (PCBs, PBDEs), polyaromatic hydrocarbons (PAHs) and phenols. All the analyzed chemicals are on the OSPAR list of priority chemicals or are indicated as endocrine disruptors on this list. The different water samples were also tested using in vitro assays to assess their potential to bind to the (human) estrogen and androgen receptor. Phase II evaluated the exposure of biota occuring in the Scheldt estuary to endocrine disrupting substances. Based on the results of the chemical analysis, priority substances were selected. Phase III studied the effects of endocrine disrupting substances occurring in the Scheldt estuary on resident mysid shrimp populations (laboratory and field studies). Substances of concern were selected and tested in the laboratory to evaluate their effects on the estuarine mysid Neomysis integer. In the context of this project, three new assays using invertebrate-specific endpoints were developed to examine the effect of endocrine disrupting chemicals (EDCs) on molting, embryogenesis and vitellogenesis of N. integer. Finally, in Phase IV laboratory and field results were used to perform a preliminary environmental risk assessment of endocrine disruptors in the Scheldt estuary. Samples were collected along the salinity gradiënt of the Scheldt estuary with the RV Belgica. Water samples were taken with Teflon-coated Go-Flo bottles (10L), sediment samples with Van Veen Grab, biota with a hyperbentic sledge, and suspended particulate matter (SPM) was continuously sampled with an Alfa Laval flow-through centrifuge. For the chemical analysis, protocols were developed to analyse estrogens, organotriazine herbicides, organochlorine pesticides, phtalates, organotins, PAHs, PCBs, and PBDEs in the different matrices: i.e. water, sediment, SPM and biota.Experimental studies were performed to analyse growth, molting, embryogenesis and vitellogenesis of N. integer. These studies were needed to develop ecotoxicological assays to evaluate EDCs on these physiological processes. To study growth of N. integer, organisms were individually transferrred in exposure solutions and molts were collected to measure the growth after each molting. To study embryogenesis, embryos were taking out of the marsupium and placed in multiwell plates. Each day survival, developmental stages and hatching was analysed. To study vitellogenesis, vitellin was isolated from eggs with gelfitration and polyclonal antibodies were developed (in rabbits). With the isolated vitellin and the antibodies an enzyme-linked immunosorbent assay (ELISA) was developed. Vitellin was quatified in ovigerous females exposed to test compound in the laboratory and in females collected from the different sampling sites of the Scheldt estuary. In addition to vitellin levels, energy allocation and testosterone metabolism was examined in field collected mysids. Finally, results from population stu

    Skin and liver diseases induced in flounder (Platichthys flesus) after long-term exposure to contaminated sediments in large-scale mesocosms.

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    Disease development in flounder (Platichthys flesus) was studied over a period of 3 years in three large mesocosms (40 m x 40 m x 3 m). Two of the mesocosms contained clean sand and the third, sharing a common water circulation with one of the clean-sand mesocosms, was stocked with contaminated dredged spoil. In this way, one of the clean-sand mesocosms was indirectly polluted via the water phase, and analysis of contaminant concentrations in sediments and flounder tissues showed that it had a status intermediate between the other two. Random samples of the flounder populations from the indirectly polluted and reference mesocosms were examined every 2 months for epidermal diseases (lymphocystis, skin ulcers, fin rot) and then released. In addition, every 6 months, random samples of fish from all three mesocosms were sacrificed for histological and chemical investigation. With regard to the development of epidermal disease, the results showed little difference between the reference mesocosm and the indirectly polluted mesocosm, with the exception that lymphocystis was significantly elevated in the indirectly polluted mesocosm. Although pollution may be a risk factor in the etiology of this disease, such a relationship would probably be obscured under field conditions due to variation arising from other factors. Histopathological analysis of the livers revealed in total four cases of hepatocellular adenoma (1.5% of sampled population) in fish from the polluted mesocosms, the first occurring after 2.5 years of exposure in fish from the indirectly polluted mesocosm. Furthermore, several other liver lesions, including foci of cellular alteration and hydropic vacuolated lesions, developed during the course of the experiment before tumor formation was apparent. Prevalences of these conditions were very much lower in the reference mesocosm than in the two polluted mesocosms. Densities of melanomacrophage centers in the liver showed a similar trend. The findings clearly indicate that long-term exposure to chemically contaminated dredged spoil can induce liver neoplasia and other liver lesions in flounder at contaminant levels comparable to those found in the natural environment

    Environmentally weathered polystyrene particles induce phenotypical and functional maturation of human monocyte-derived dendritic cells

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    Micro- and nanoplastics (MNP) are ubiquitously present in the environment due to their high persistence and bioaccumulative properties. Humans get exposed to MNP via various routes and consequently, they will encounter dendritic cells (DC) which are antigen-presenting cells involved in regulating immune responses. The consequences of DC exposure to MNP are an important, yet understudied, cause of concern. Therefore, this study aimed to assess the uptake and effect of MNP in vitro by exposing human monocyte-derived dendritic cells (MoDC) to virgin and environmentally weathered polystyrene (PS) particles of different sizes (0.2, 1, and 10 µm), at different concentrations ranging from 1 to 100 µg/ml. The effects of these particles were examined by measuring co-stimulatory surface marker (i.e. CD83 and CD86) expression. In addition, T-cell proliferation was measured via a mixed-leukocyte reaction (MLR) assay. The results showed that MoDC were capable of absorbing PS particles, and this was facilitated by pre-incubation in heat-inactivated (HI) plasma. Furthermore, depending on their size, weathered PS particles in particular caused increased expression of CD83 and CD86 on MoDC. Lastly, weathered 0.2 µm PS particles were able to functionally activate MoDC, leading to an increase in T-cell activation. These in vitro data suggest that, depending on their size, weathered PS particles might act as an immunostimulating adjuvant, possibly leading to T-cell sensitization

    Knowledge Hub on the Integrated Assessment of Chemical Contaminants and their Effects on the Marine Environment

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    In a time of environmental awareness, spurred on by the possibility that our world is threatened by climate change, it is important to remember that there are other anthropogenic pressures, which are also essential for addressing the protection of the marine and coastal environment. Pollution is a global, complex issue that contributes to biodiversity loss and poor environmental health and comes from the production and release of many of the synthetic chemicals that we use in our daily lives. Chemical contaminants are often underrepresented as a major contributor of environmental deterioration. The Joint Programming Initiative Healthy and Productive Seas and Oceans (JPI Oceans) established in 2018 the JPI Oceans Knowledge Hub on the integrated assessment of chemical contaminants and their effects on the marine environment. The purpose of the Knowledge Hub was to provide recommendations on how to improve the methodological basis for marine chemical status assessment. The work has resulted in the following policy paper which focuses on improving the efficiency and implementation of integrated assessment methodology of effects of chemicals of emerging concern. Substantial additional knowledge of biological effects is needed to achieve Good Environmental Status (GES) of our oceans and coastal areas. The Knowledge Hub is represented by highly skilled scientists and policy makers, appointed by the JPI Oceans Management Board, to ensure that the recommendations provided are useful for policy making
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