The NORMAN Association and the European Partnership for Chemicals Risk Assessment (PARC): let’s cooperate! [Commentary]

The Partnership for Chemicals Risk Assessment (PARC) is currently under development as a joint research and innovation programme to strengthen the scientific basis for chemical risk assessment in the EU. The plan is to bring chemical risk assessors and managers together with scientists to accelerate method development and the production of necessary data and knowledge, and to facilitate the transition to next-generation evidence-based risk assessment, a non-toxic environment and the European Green Deal. The NORMAN Network is an independent, well-established and competent network of more than 80 organisations in the field of emerging substances and has enormous potential to contribute to the implementation of the PARC partnership. NORMAN stands ready to provide expert advice to PARC, drawing on its long experience in the development, harmonisation and testing of advanced tools in relation to chemicals of emerging concern and in support of a European Early Warning System to unravel the risks of contaminants of emerging concern (CECs) and close the gap between research and innovation and regulatory processes. In this commentary we highlight the tools developed by NORMAN that we consider most relevant to supporting the PARC initiative: (i) joint data space and cutting-edge research tools for risk assessment of contaminants of emerging concern; (ii) collaborative European framework to improve data quality and comparability; (iii) advanced data analysis tools for a European early warning system and (iv) support to national and European chemical risk assessment thanks to harnessing, combining and sharing evidence and expertise on CECs. By combining the extensive knowledge and experience of the NORMAN network with the financial and policy-related strengths of the PARC initiative, a large step towards the goal of a non-toxic environment can be taken

Epithelial cell renewal in the digestive gland and stomach of mussels, season, age and tidal regime related variations

The natural variability in cell proliferation activity in the epithelium of the digestive gland and stomach was investigated in mussels, Mytilus galloprovincialis (Lmk), of different age and tidal level at different seasons. After treating mussels with the thymidine analogue bromodeoxyuridine (BrdU) for 6 hours, BrdU immunohistochemistry was performed every 2 hours for the next 36. The relative proportion of BrdU positive cells was quantified as BrdU labelling (‰). Marked seasonal differences were recorded in BrdU labelling, with much higher proliferating activity in summer than in autumn and winter. Cell proliferation seemed not to be significantly dissimilar between mussels of different age (size). In contrast, the digestive gland epithelium of mussels from intertidal and subtidal populations differed not only in the levels but also in the pattern of variation of BrdU labelling, which in intertidal mussels appeared to be modulated by photoperiod and tide, unlike in subtidal mussels, in which variations followed a circatidal pattern

Immunolocalization of metallothioneins in different tissues of turbot (Scophthalmus maximus) exposed to Cd

Metallothioneins (MT) were localized by immunochemistry in different organs and cell compartments of turbot exposed to sublethal concentrations (100 ppb) of Cd for 7 days. The polyclonal rabbit anti-cod MT antibody (NIVA, Norway) applied herein exhibited positive cross-reactivity with turbot MTs. Immunoreactive MTs were localized in the branchial epithelium, in the liver and in the kidney of turbot. In Cd exposed fishes MTs were demonstrated mainly in branchial chloride cells (CC) and to a lesser extend in the area where progenitor cells are located and in the cells of the respiratory epithelium (secondary lamellae). A higher staining intensity for MTs was observed in CC of the interlamelar space of the main branchial epithelium in comparison with control CC. MT-staining was also observed in the chondroblasts of the cartilage and in the erythrocytes within blood vessels both in control and Cd-exposed specimens. MT immunoreaction was high in the liver hepatocytes and weak in the epithelium of the proximal portion of the kidney in exposed turbot. The tegument, spleen and muscle were devoid of any immunolabelling in both treatments. Ultrastructural studies at the transmission electron microscope revealed that Cd-induced MTs were mainly located in the cytoplasm of gill CC, the lysosomes and the cytoplasm of hepatocytes and in the basal labyrinth of kidney proximal nephrocytes. The differential localization/induction of MTs in different cell types described hereby suggests that the quantification of the specific expression of MT may be used in biomonitoring programs as a biomarker of Cd exposure in aquatic environments

Structure of peroxisomes and activity of the marker enzyme catalase in digestive epithelial cells in relation to PAH content of mussels from two Basque estuaries (Bay of Biscay) Seasonal and site-specific variations

The aim of the present work was to study the seasonal as well as the site-specific variations in the structure of peroxisomes and in the activity of the peroxisomal marker enzyme catalase in digestive epithelial cells of mussels to validate the potential use of these parameters as early biomarkers of environmental organic pollution in estuarine ecosystems. For this purpose, mussels were sampled monthly for 14 months in two Basque estuaries (Bay of Biscay) with different degrees of pollution. Stereological procedures were applied to detect changes in peroxisome structure, and microspectrophotometry was used to quantify changes in catalase activity. The animals from the two studied sampling sites presented differences in polycyclic aromatic hydrocarbon (PAH) burdens, mussels from Plentzia generally showing lower total PAH contents than mussels from Galea. The peroxisome structure of the animals from the two estuaries suffered seasonal variations that were of different kind and intensity in both sites. In this way, a strong peroxisome proliferatory response was found in mussels sampled in Plentzia during the summer months, while mussels from Galea presented few variations along the year. Catalase activity behaved similarly in the animals sampled in the two estuaries, with higher values in spring. It appeared that mussels exposed chronically to PAHs and other pollutants, such as those from Galea, lost their ability to respond to this exposure in terms of peroxisome proliferation. In contrast, mussels collected in Plentzia effectively responded to an increased bioavailability of organic pollutants during the summer by increasing peroxisome volume and surface and numerical densities in digestive epithelial cells. However, these increases were transient because elevated PAH body burdens detected in mussels sampled in Plentzia in autumn were not accompanied by a peroxisome proliferatory response. Further studies are needed before changes in peroxisomal structure and in the activity of catalase could be used as early biomarkers to assess environmental quality in pollution monitoring programs like the Mussel Watch

Assessment of ecosystem health disturbance in mangrove-lined Caribbean coastal systems using the oyster Crassostrea rhizophorae as sentinel species

18 páginasThis investigation was aimed at contributing to develop a suitable multi-biomarker approach for pollution monitoring in mangrove-lined Caribbean coastal systems using as sentinel species, the mangrove cupped oyster, Crassostrea rhizophorae. A pilot field study was carried out in 8 localities (3 in Nicaragua; 5 in Colombia), characterized by different environmental conditions and subjected to different levels and types of pollution. Samples were collected in the rainy and dry seasons of 2012–2013. The biological effects at different levels of biological complexity (Stress-on-Stress response, reproduction, condition index, tissue-level biomarkers and histopathology) were determined as indicators of health disturbance, integrated as IBR/n index, and compared with tissue burdens of contaminants in order to achieve an integrative biomonitoring approach. Though modulated by natural variables and confounding factors, different indicators of oyster health, alone and in combination, were related to the presence of different profiles and levels of contaminants present at low-to-moderate levels. Different mixtures of persistent (As, Cd, PAHs) and emerging chemical pollutants (musk fragrances), in combination with different levels of organic and particulate matter resulting from seasonal oceanographic variability and sewage discharges, and environmental factors (salinity, temperature) elicited a different degree of disturbance in ecosystem health condition, as reflected in sentinel C. rhizophorae. As a result, IBR/n was correlated with pollution indices, even though the levels of biological indicators of health disturbance and pollutants were low-to-moderate, and seasonality and the incidence of confounding factors were remarkable. Our study supports the use of simple methodological approaches to diagnose anomalies in the health status of oysters from different localities and to identify potential causing agents and reflect disturbances in ecosystem health. Consequently, the easy methodological approach used herein is useful for the assessment of health disturbance in a variety of mangrove-lined Caribbean coastal systems using mangrove cupped oysters as sentinel species