Thresholds for Endocrine Disrupters and Related Uncertainties

The European Commission, under Directorate-General for Environment (DG ENV) created an ad hoc group of Commission Services and Member States to serve the EU Community Strategy on Endocrine Disrupters. The ad hoc group created the Endocrine Disrupters Expert Advisory Group (ED EAG) in November 2011 to provide detailed reflections on scientific issues relevant to identifying and assessing endocrine disrupting substances, not specific to any regulatory framework. The European Commission's Joint Research Centre was tasked with facilitating and chairing meetings of the ED EAG and preparing this report. The scope of the present report is to capture the experts' opinions on scientific issues relevant to the likelihood of the existence of thresholds for a biological response of an organism to an ED, in particular considering thresholds of adversity and the uncertainties associated with reliably estimating such thresholds from experimental data. The question although relevant to the evaluation of EDs per se was specifically raised by the ad hoc group in relation to a review of the REACH regulation with respect to treatment of EDs under authorisation (Article 138 (7)).JRC.I.5-Systems Toxicolog

Key scientific issues relevant to the identification and characterisation of endocrine disrupting substances - Report of the Endocrine Disrupters Expert Advisory Group

The European Commission, under Directorate-General for Environment (DG ENV) as file leader of the Community Strategy on Endocrine Disrupters, In 2010, DG ENV created an ad hoc group of Commission Services and Member States on the EU Community Strategy on Endocrine Disrupters. The ad hoc group created the Endocrine Disrupters Expert Advisory Group (ED EAG) in November 2011 to provide scientific advice on the development of criteria for identification of EDs. The European Commission's Joint Research Centre was tasked with running the expert sub-group, consisting of around 40 experts nominated by Member State regulatory authorities, relevant industry associations and non-governmental consumer/environmental protection organisations. This report captures the experts' opinions on key scientific issues relevant to the identification and characterisation of endocrine disrupting substances (EDs). It provides one input to the Commission’s decisions on the establishment of horizontal criteria for the identification of EDs to be applied as appropriate across all relevant pieces of legislation concerning the control and risk management of chemicals substances (including pesticides, biocides, pharmaceuticals, industrial chemicals, controls on water quality, occupational exposure, etc).JRC.I.5-Systems Toxicolog

Description of Prototype Modes-of-Action Related to Repeated Dose Toxicity

This report presents the definition and detailed documentation of chosen toxicological MoAs associated with repeated dose target organ toxicity as a first step in building a "prototype" safety assessment framework. In addition to providing a detailed description of the two chosen MoAs related to chronic liver toxicity, namely "MoA from Protein Alkylation to Liver Fibrosis" and "MoA from Liver X Receptor Activation to Liver Steatosis", the report also describes the working process leading to this result including the problems that have been encountered. The exercise followed as far as possible relevant WHO-IPCS and OECD guidance. The report represents the first deliverable of a contract of work between Cosmetics Europe and the European Commission's Joint Research Centre for supplementing the work of the SEURAT-1 research cluster.JRC.I.5-Systems Toxicolog

Emerging links between cadmium exposure and insulin resistance: Human, animal, and cell study data

Recent research has helped clarify the role of cadmium (Cd) in various pathological states. We have demonstrated Cd involvement in pancreatic cancer, as well as the bioaccumulation of Cd in the pancreas. Bioaccumulation and increased toxicity suggest that Cd may also be involved in other pancreas-mediated diseases, like diabetes. Cd falls into the category of "hyperglycemic" metals, i.e., metals that increase blood glucose levels, which could be due to increased gluconeogenesis, damage to β-cells leading to reduced insulin production, or insulin resistance at target tissue resulting in a lack of glucose uptake. This review addresses the current evidence for the role of Cd, leading to insulin resistance from human, animal, and in vitro studies. Available data have shown that Cd may affect normal insulin function through multiple pathways. There is evidence that Cd exposure results in the perturbation of the enzymes and modulatory proteins involved in insulin signal transduction at the target tissue and mutations of the insulin receptor. Cd, through well-described mechanisms of oxidative stress, inflammation, and mitochondrial damage, may also alter insulin production in β-cells. More work is necessary to elucidate the mechanisms associated with Cd-mediated insulin resistance

A new threat from an old enemy: Re‑emergence of coronavirus (Review)

The new outbreak of coronavirus from December 2019 has brought attention to an old viral enemy and has raised concerns as to the ability of current protection measures and the healthcare system to handle such a threat. It has been known since the 1960s that coronaviruses can cause respiratory infections in humans; however, their epidemic potential was understood only during the past two decades. In the present review, we address current knowledge on coronaviruses from a short history to epidemiology, pathogenesis, clinical manifestation of the disease, as well as treatment and prevention strategies. Although a great amount of research and efforts have been made worldwide to prevent further outbreaks of coronavirus‑associated disease, the spread and lethality of the 2019 outbreak (COVID‑19) is proving to be higher than previous epidemics on account of international travel density and immune naivety of the population. Only strong, joint and coordinated efforts of worldwide healthcare systems, researchers, and pharmaceutical companies and receptive national leaders will succeed in suppressing an outbreak of this scale

Alternative methods for regulatory toxicology – a state-of-the-art review

This state-of-the art review is based on the final report of a project carried out by the European Commission’s Joint Research Centre (JRC) for the European Chemicals Agency (ECHA). The aim of the project was to review the state of the science of non-standard methods that are available for assessing the toxicological and ecotoxicological properties of chemicals. Non-standard methods refer to alternatives to animal experiments, such as in vitro tests and computational models, as well as animal methods that are not covered by current regulatory guidelines. This report therefore reviews the current scientific status of non-standard methods for a range of human health and ecotoxicological endpoints, and provides a commentary on the mechanistic basis and regulatory applicability of these methods. For completeness, and to provide context, currently accepted (standard) methods are also summarised. In particular, the following human health endpoints are covered: a) skin irritation and corrosion; b) serious eye damage and eye irritation; c) skin sensitisation; d) acute systemic toxicity; e) repeat dose toxicity; f) genotoxicity and mutagenicity; g) carcinogenicity; h) reproductive toxicity (including effects on development and fertility); i) endocrine disruption relevant to human health; and j) toxicokinetics. In relation to ecotoxicological endpoints, the report focuses on non-standard methods for acute and chronic fish toxicity. While specific reference is made to the information needs of REACH, the Biocidal Products Regulation and the Classification, Labelling and Packaging Regulation, this review is also expected to be informative in relation to the possible use of alternative and non-standard methods in other sectors, such as cosmetics and plant protection products.JRC.I.5-Systems Toxicolog

Study of the in vivo genotoxicity of plant protection products' combinations

In the present dissertation, the in vivo genotoxicity of 4 binary combinations of pesticides’ commercial formulations as well as the respective 8 pesticides’ commercial formulations separately, were studied. For this purpose the in vivo bone marrow micronucleus test and the DNA alkaline elution technique in liver tissue were performed, both using Wistar rats. The studied formulations’ active substances and their combinations were: atrazine & pendimethalin, paraquat & linuron, captan & carbendazim and thiram & thiophanate methyl. In order to be implemented, the alkaline elution technique as well as the fluorometric DNA quantification method were modified and validated appropriately. For the evaluation of the MN incidences that were obtained from the micronucleus test, different non-parametric statistical methods were implemented and their results were co-evaluated. As a result of the study of the 4 combinations and the 8 individual formulations, it was found that under the given experimental conditions, chromosomal aberrations are caused by the combination of captan and carbendazim formulations and by the formulations of carbendazim and thiophanate methyl when are administered separately. Cytotoxicity in the bone marrow was evidenced by the following combinations: a) paraquat and linuron b) captan and carbendazim and c) thiram and thiophanate methyl. Cytotoxicity was also caused by the formulations of linuron, carbendazim, thiram and thiophanate methyl while a weak decrease of the PCE / RBC % ratio, used as bone marrow cytotoxicity indicator, was observed from paraquat and captan formulations. DNA strand breaks were caused only by the paraquat and linuron formulations when they were administered separately and to a smaller extent, from pendimethalin formulation. A less than additive interaction with respect to the MN incidence was observed from the combination of captan and carbendazim formulations. A lower than expected cytotoxicity in bone marrow was observed for the combination of paraquat and linuron formulations while the cytotoxicity observed for the combination of captan and carbendazim formulations was greater than the expected one. Finally, interaction was observed between the formulations of paraquat and linuron, which resulted in the inhibition of the inducement of DNA strand breaks observed when both formulations were administered separately. The studies that were performed during the current dissertation indicated the necessity for studying the combinations of the pesticides’ formulations, usually used in agriculture, in the same way as it is done for the individual active substances, instead of predicting their potency based on existing data for the respective active substances and assuming zero interaction between them. This need is even more imperative in the case of genotoxicity studies as according to EU 91/414/EEC directive, the use of genotoxic active substances, as well as their formulation or formulations’ combinations, is prohibited in all EU member states.Στην παρούσα διατριβή μελετήθηκε η in vivo γονοτοξικότητα 4 δυαδικών συνδυασμών σκευασμάτων φυτοπροστατευτικών προϊόντων και των αντίστοιχων 8 μεμονωμένων σκευασμάτων, με τη δοκιμασία του μικροπυρήνα για την ανίχνευση χρωμοσωμικών βλαβών σε μυελό των οστών επίμυων και με τη δοκιμασία αλκαλικής εκχύλισης του DNA για την ανίχνευση θραύσεων αλύσου του DNA σε ηπατικό ιστό επίμυων. Οι δραστικές ουσίες των σκευασμάτων που μελετήθηκαν και οι μεταξύ τους συνδυασμοί τους ήταν οι εξής: atrazine & pendimethalin, paraquat & linuron, captan & carbendazim και thiram & thiophanate methyl. Για την εφαρμογή της δοκιμασίας της αλκαλικής εκχύλισης πραγματοποιήθηκε τροποποίηση και αξιολόγηση τόσο της τεχνικής της αλκαλικής εκχύλισης όσο και της μεθόδου του φθορισμομετρικού ποσοτικού προσδιορισμού του DNA. Για την αξιολόγηση της συχνότητας εμφάνισης μικροπυρήνα που προέκυψε ως αποτέλεσμα της δοκιμασίας του μικροπυρήνα, εφαρμόσθηκαν και συν-αξιολογήθηκαν διαφορετικές μη - παραμετρικές στατιστικές δοκιμασίες. Από τη μελέτη των 4 συνδυασμών και των 8 μεμονωμένων σκευασμάτων φυτοπροστατευτικών προϊόντων προέκυψε ότι, υπό τις δεδομένες πειραματικές συνθήκες, χρωμοσωμικές βλάβες προκαλούνται από το συνδυασμό των σκευασμάτων του captan και του carbendazim και από τα μεμονωμένα σκευάσματα του carbendazim και του thiophanate methyl. Κυτταροτοξική δράση στον μυελό των οστών επίμυων παρατηρήθηκε για τους συνδυασμούς των σκευασμάτων α) του paraquat και του linuron, β) του captan και του carbendazim και γ) του thiram και του thiophanate methyl. Κυτταροτοξικότητα προέκυψε επίσης για τα μεμονωμένα σκευάσματα του linuron, του carbendazim, του thiram και του thiophanate methyl ενώ μία ασθενής μείωση του λόγου % PCE / RBC ως δείκτη κυτταροτοξικότητας παρατηρήθηκε και από τα σκευάσματα του paraquat και του captan. Πρόκληση θραύσεων αλύσου του DNA παρατηρήθηκε μόνο από τα μεμονωμένα σκευάσματα του paraquat, του linuron και σε μικρότερη ένταση και από το σκεύασμα της pendimethalin. Αλληλεπίδραση μεταξύ των συστατικών των σκευασμάτων, με αποτέλεσμα την σχετική μείωση της αναμενόμενης συχνότητας εμφάνισης ΜΝ, παρατηρήθηκε για το συνδυασμό των σκευασμάτων του captan και του carbendazim. Επίσης, παρατηρήθηκε μείωση της αναμενόμενης κυτταροτοξικότητας στον μυελό των οστών για το συνδυασμό των σκευασμάτων του paraquat και του linuron, ενώ μεγαλύτερη από την αναμενόμενη ήταν η κυτταροτοξικότητα του συνδυασμού των σκευασμάτων του captan και του carbendazim. Τέλος, αλληλεπίδραση με αποτέλεσμα την αναστολή της πρόκλησης θραύσεων αλύσου του DNA παρατηρήθηκε για το συνδυασμό των σκευασμάτων του paraquat και του linuron. Από το σύνολο των μελετών που πραγματοποιήθηκαν στα πλαίσια της παρούσας διατριβής, καταδεικνύεται η αναγκαιότητα μελέτης των συνδυασμών σκευασμάτων φυτοπροστατευτικών προϊόντων που χρησιμοποιούνται στη γεωργία, κατά τον ίδιο τρόπο που μελετώνται και οι μεμονωμένες δραστικές ουσίες αντί της πρόβλεψης της δραστικότητάς τους με βάση υπάρχοντα στοιχεία για τα συστατικά τους και υποθέτοντας μηδενική αλληλεπίδραση. Η ανάγκη αυτή είναι ακόμα πιο επιτακτική στην περίπτωση της μελέτης της γονοτοξικότητας καθώς η ύπαρξη τέτοιας επίδρασης αποτελεί σύμφωνα με την Οδηγία 91/414/EEC της Ευρωπαϊκής Ένωσης, επαρκή αιτία για την απαγόρευση της χρήσης της δραστικής ουσίας, του σκευάσματος ή του συνδυασμού που την προκαλεί, στα κράτη μέλη της

The role of toxic stimuli combinations in determining safe exposure limits

This editorial addresses the effects of toxic stimuli combinations on determination of safe Exposure Limits. Examination of thousands of Medline abstracts showed typically that combinations of toxic stimuli can produce damage even when the exposure level of each member of the combination is less than the lowest exposure level of the member that produced damage when tested in isolation. The synergy of the toxic stimuli in combination means less of each component stimulus is required to cause damage compared to exposure levels when tested in isolation. This Editorial concludes there is no reason to believe today that the Exposure Limits on potentially toxic stimuli that have been set by the regulatory agencies are fully protective against serious adverse health effects in all real life exposure scenarios. The conclusion is applicable to essentially all potential contributing factors to disease amenable to Exposure Limits, including not only chemicals but other types of exposures such as radiofrequency radiation (RFR). Keywords: Synergetic effects, Combined effects, Additive effects, Safe exposure limits, Combination toxicity, Joint toxicity, Cumulative risk assessmen