β-Nitrostyrene, an important intermediate in chemical industry, shows relevant anti-proliferative and pro-apoptotic potential and has thus been suggested for potential use in tumor chemotherapy. If not derivatized, β-nitrostyrene is however, highly reactive and possess (geno)toxic potential. To decipher structural elements relevant for biological activity, crucial for both, chemical risk assessment and potential drug development, a panel of nine structural derivatives of β-nitrostyrene, was put together. It included structures with and without nitrovinyl moiety and was based on fingerprint similarity, QSAR-based mutagenicity alerts, and literature reports. It comprised simple structures like styrene and more complex structures such as 2-methoxy-5-[(E)-2-nitroethenyl]phenol. In vitro experiments in human WS1 and mouse L5178/TK± cells demonstrated that the nitrovinyl moiety of β-nitrostyrene seems vital for its cytotoxic (membrane damage, metabolic competence) and genotoxic (clastogenicity, mutagenicity) properties. The extent of adversity varied with modification of structural elements. For example 1-nitro-2-[(E)-2-nitroethenyl]benzene led to 2.3-fold higher mean tail intensities in the alkaline comet assay than β-nitrostyrene. Notably, all derivatives with a nitrovinyl moiety, except 5-[(E)-2-nitroethenyl]-1,3-benzodioxole, induced DNA double-strand breaks, as judged by γH2A.X induction. In conclusion, our study identified structural elements responsible for the cyto- and genotoxic potential of β-nitrostyrene, demonstrating that minor structural changes can significantly alter its adverse biological activity.

European populations are chronically exposed to fluoride, as fluoride is supplemented for caries prophylaxis and is furthermore present in some food sources. As there is evidence that fluoride exposure at drinking water concentrations above 1.5 mg/L is associated with lower IQ in children, total daily intake in Europe might be close to or above this exposure level. Concerning health effects in Europe, epidemiological data are limited. Therefore, it would be beneficial to consider existing studies from non-EU countries to transfer observed effects to the exposure situation in Europe. Additionally, animal data could also deliver supporting information, if equivalent doses could be calculated. In this work, a methodology was developed to determine daily fluoride intake and excretion in Europe and align it to concentrations reported in animal and epidemiological studies. With this, a total daily intake of 2.05-mg fluoride for 3-year-old children and 3.8-mg fluoride for adults was estimated. For 3-year-olds, this value exceeds the current recommendations of fluoride intake by EFSA and even the tolerable upper intake level. The daily urinary fluoride excretion was calculated to be 0.72 mg/day, and for adults, it was 2.05 mg/day. For in vivo studies, rat exposure to fluoride drinking water concentrations of 12.5 ppm was considered to be equivalent to the daily fluoride intake in Europe. With the presented approach, equivalent doses can be applied to select international epidemiological as well as in vivo studies reflecting the fluoride exposure situation in European countries to extrapolate potential health effects.

A risk-based strategy is presented aimed at prioritizing chemicals screened as potential persistent, mobile and toxic (PMT) or very persistent and very mobile (vPvM) substances. Prioritization is done to strengthen the decision-making process regarding actions that might be taken against chemicals screened as potential PMT/vPvM substances. Such actions can range from acquiring additional data aimed at reducing uncertainties in toxicological effect concentrations or internal exposure concentrations to—in case of acceptable uncertainty—suggesting compounds for prevention and/or removal measures in order to limit future exposure. The prioritization strategy is developed within the ZeroPM project and applies a variety of tools, including in silico and in vitro models for exposure and toxicity hazard assessment. These tools will be applied to chemicals identified as PMT/vPvM substances, with a preliminary emphasis on substances belonging to three chemical classes, i.e. perfluorinated compounds, triazines and triazoles. Here we describe the ZeroPM approach providing a proof-of-principle illustrative example, based on data-rich substances, results from which demonstrate how prioritization can be achieved using a risk-based approach that uses data obtained from new approach methodologies (NAMs) and environmental exposure concentrations, obtained either through modelling or monitoring studies. Results are communicated using a risk-based prioritization matrix, which can be used to help to communicate prioritization needs, such as identifying data gaps or for guiding actions aimed at mitigating exposure. The precision and accuracy of the prioritization matrix is evaluated using several data-rich chemicals, which identifies perfluorooctanoic acid and perfluorooctane sulfonic acid as high priority, due to a combination of toxicity and exposure estimates, whereas atrazine and melamine are observed at lower priority. The proposed risk-based prioritization framework thus represents a complementary source of information that should help support regulatory decision-making for PMT/vPvM substances.

Abstract New approach methodologies (NAMs) are an integral part of Next Generation Risk Assessment (NGRA). NAMs consider in-vitro, in-silico, in-chemistry test methods. These can be linked by PBK modelling and in-vitro in-vivo extrapolation (IVIVE) to external exposure concentrations. Thus NAM-based test methods require translation from external exposure to internal exposure and vice versa. Additionally aggregated external human exposure by inhalation and dermal route will be often based on measurements or are estimated by tools usually applied under REACH. PBK modelling allows to predict chemical and metabolite concentrations over time and in relevant body compartments (human plasma and/or tissues) for given exposure scenarios (forward dosimetry). By turning around the approach (reverse dosimetry) acceptable external exposure levels (such as OEL) may be derived on internal thresholds (in-vitro effect data, compound specific threshold values, human biomonitoring data). Thereby, maximal external exposure concentrations below which human exposure is considered safe can be derived. The presentation will contain the description of the approach to derive acceptable occupational exposure levels (OELs) based on internal threshold values. The approach will be discussed with a case study to illustrate the applicability. The approach is beneficial especially for case compounds such as NMP where aggregated exposure is determined by inhalation and dermal by air.

Novel medical devices must conform to medical device regulation (MDR) for European market entry. Likewise, chemicals must comply with the Registration, Evaluation, Authorization and Restriction of Chemicals (REACh) regulation. Both pose regulatory challenges for manufacturers, but concordantly provide an approach for transferring data from an already registered device or compound to the one undergoing accreditation. This is called equivalence for medical devices and read-across for chemicals.Although read-across is not explicitly prohibited in the process of medical device accreditation, it is usually not performed due to a lack of guidance and acceptance criteria from the authorities. Nonetheless, a scientifically justified read-across of material-based endpoints, as well as toxicological assessment of chemical aspects, such as extractables and leachables, can prevent failure of MDR device equivalence if data is lacking. Further read-across, if applied correctly can facilitate the standard MDR conformity assessment.The need for read-across within medical device registration should let authorities to reconsider device accreditation and the formulation of respective guidance documents. Acceptance criteria like in the European Chemicals Agency (ECHA) read-across assessment framework (RAAF) are needed. This can reduce the impact of the MDR and help with keeping high European innovation device rate, beneficial for medical device patients.

BACKGROUND:This study aims to facilitate the identification of similar devices for both, the European Medical Device Regulation (MDR) and the US 510(k) equivalence pathway by leveraging existing data. Both are related to the regulatory pathway of read across for chemicals, where toxicological data from a known substance is transferred to one under investigation, as they aim to streamline the accreditation process for new devices and chemicals. RESEARCH DESIGN AND METHODS:This study employs latent semantic analysis to generate similarity values, harnessing the US Food and Drug Administration 510k-database, utilizing their 'Device Descriptions' and 'Intended Use' statements. RESULTS:For the representative inhaler cluster, similarity values up to 0.999 were generated for devices within a 510(k)-predicate tree, whereas values up to 0.124 were gathered for devices outside this group. CONCLUSION:Traditionally, MDR equivalence involves manual review of many devices, which is laborious. However, our results suggest that the automated calculation of similarity coefficients streamlines this process, thus reducing regulatory effort, which can be beneficial for patients needing medical devices. Although this study is focused on the European perspective, it can find application within 510(k) equivalence regulation. The conceptual approach is reminiscent of chemical fingerprint similarity analysis employed in read-across.

Abstract The European regulation on Registration, Evaluation and Authorization of Chemicals (REACH) requires generation of information on the intrinsic properties (including hazard) of registered substances depending on their tonnage. In situations where human or environmental exposure is absent or not significant, exposure-based adaptation (EBA) may be considered. EBA comprises all types of modifications of the standard information requirements, of which the exposure based waiving (EBW) is an option that allows to waive higher tier mammalian toxicity studies. In order to justify for a defined endpoint the omission of the standard information requirement, a high level of confidence is needed to demonstrate no or no significant exposure. Thresholds for toxicological concern (TTC) are used to decide on acceptable oral intakes. This concept has recently been expanded to inhalation route of exposure. These values can easily be converted in inhalation exposure levels or vapour pressures below which no concern exist. These cut off criteria provide the basis for robust science-based EBA justifications and can be used to identify the most relevant exposure route(s) for new testing proposals. Even though, this approach is more challenging for dermal uptake iTTC values can be used together with PBK modelling and dermal uptake to calculate maximal external exposure concentrations below which human exposure is considered safe, and which can be applied for exposure-based waiving.

Man-made vitreous fibers (MMVF) comprise diverse materials for thermal and acoustic insulation, including stone wool. Depending on dimension, durability, and dose, MMVF might induce adverse health effects. Therefore, early predictive in vitro (geno)toxicity screening of new MMVF is highly desired to ensure safety for exposed workers and consumers. Here, we investigated, as a starting point, critical in vitro screening determinants and pitfalls using primary rat alveolar macrophages (AM) and normal rat mesothelial cells (NRM2). A stone wool fiber (RIF56008) served as an exemplary MMVF (fibrous vs. ground to estimate impact of fiber shape) and long amosite (asbestos) as insoluble fiber reference. Materials were comprehensively characterized, and in vivo-relevant in vitro concentrations defined, based on different approaches (low to supposed overload: 0.5, 5 and 50 µg/cm2). After 4–48 h of incubation, certain readouts were analyzed and material uptake was investigated by light and fluorescence-coupled darkfield microscopy. DNA-strand break induction was not morphology-dependent and nearly absent in both cell types. However, NRM2 demonstrated material-, morphology- and concentration-dependent membrane damage, CINC-1 release, reduction in cell count, and induction of binucleated cells (asbestos > RIF56008 > RIF56008 ground). In contrast to NRM2, asbestos was nearly inactive in AM, with CINC-1 release solely induced by RIF56008. In conclusion, to define an MMVF-adapted, predictive in vitro (geno)toxicity screening tool, references, endpoints, and concentrations should be carefully chosen, based on in vivo relevance, and sensitivity and specificity of the chosen cell model. Next, further endpoints should be evaluated, ideally with validation by in vivo data regarding their predictivity.

Background Oxidative stress is thought to be related to many diseases. Furthermore, it is hypothesized that radiofrequency electromagnetic fields (RF-EMF) may induce excessive oxidative stress in various cell types and thereby have the potential to compromise human and animal health. The objective of this systematic review (SR) is to summarize and evaluate the literature on the relation between the exposure to RF-EMF in the frequency range from 100 kHz to 300 GHz and biomarkers of oxidative stress. Methods The SR framework was developed following the guidelines established in the WHO Handbook for Guideline Development and NTP/OHAT’s Handbook for Conducting a Literature-Based Health Assessment. We used the latter handbook’s methodology for implementing the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach for environmental health assessments.We searched the following databases up until June 30, 2023: PubMed, Embase, Web of Science Core Collection, Scopus, and the EMF-Portal. The reference lists of included studies and retrieved review articles were also manually searched.We rated Risk of Bias (RoB) using the OHAT RoB Rating Tool and assessed publication bias using funnel plots of included studies. We assessed the certainty of the evidence (high, moderate, low, or inadequate) for an association between RF-EMF and oxidative stress using an adapted version of the GRADE framework.Data were extracted according to a predefined set of forms developed in DistillerSR.Data were analysed after grouping them first as in vitro or in vivo and then according to outcome category, species category, and exposed tissue. We synthesized study results using a random effects meta-analysis when study characteristics were judged sufficiently similar to be combined and heterogeneity (I2) was lower than 75 %, otherwise we describe the findings narratively. Results Fifty-six (56) studies, 45 in vivo and 11 in vitro, exposed to frequencies in the range 800–2450 MHz, were included in the SR after eliminating 11,543 publications because they did not meet the criteria defined in the published protocol (Henschenmacher et al., 2022). Of 56 studies 51 studies with 168 individual results were included in the meta-analysis. Together, these studies examined six human in vitro samples and fifty animal samples, including rodents (mice, rats, hamsters, and guinea pigs, [n = 46]) and rabbits [n = 4]. RF-EMF were predominantly applied as continuous wave exposures in these studies. The outcome biomarkers for modified proteins and amino acids were measured in 30 studies, for oxidized DNA bases in 26 studies, for oxidized lipids in 2 studies and hydrogen peroxide production in 2 studies. Outcomes were mostly measured in the brain (n = 22), liver (n = 9), cells (n = 9), blood (n = 6), and testis (n = 2). RoB in studies was high, mainly due to biases in exposure and outcome assessment. In vivo studies Brain: The effect on biomarkers for oxidized DNA bases in the rodent brain (five studies, n = 98) had an inconsistent effect, varying from a large decrease with a standardized mean difference (SMD) of −3.40 (95 % CI [−5.15, −1.64]) to a large increase with an SMD of 2.2 (95 % CI [0.78, 3.62]). In the brain of rabbits (two studies, n = 44), the effect sizes also varied, from an SMD of −1.06 (95 % CI [−2.13, 0.00]) to an SMD of 5.94 (95 % CI [3.14, 8.73]). The effect on biomarkers for modified proteins and amino acids in the rodent brain (15 studies, n = 328) also varied from a large decrease with an SMD of −6.11 (95 % CI [−8.16, −4.06]) to a large increase with an SMD of 5.33 (95 % CI [2.49, 8.17]).The effect on biomarkers for oxidized lipids in the brain of rodents (one study, n = 56) also varied from a large decrease with SMD = −4.10 (95 % CI [−5.48, −2.73]) to SMD = 1.27 (95 % CI [0.45, 2.10]).Liver: The effect on biomarkers for oxidized DNA bases in the rodent liver (two studies, n = 26) was inconsistent with effect sizes in both directions: SMD = −0.71 (95 % CI [−1.80, 0.38]) and SMD = 1.56 (95 % CI [0.19, 2.92]). The effect on biomarkers for oxidized DNA bases in the rabbits’ liver (two studies, n = 60) was medium with a pooled SMD of 0.39 (95 % CI [−0.79, 1.56]).Biomarkers for modified proteins and amino acids in the liver of rodents (six studies, n = 159) increased with a pooled SMD of 0.55 (95 % CI [0.06, 1.05]).Blood: The effect of RF-EMF on biomarkers for oxidized DNA bases in rodent blood (four studies, n = 104) was inconsistent, with SMDs ranging from −1.14 (95 % CI [−2.23, −0.06]) to 1.71 (95 % CI [−0.10, 3.53]).RF-EMF had no effect on biomarkers for modified proteins and amino acids in rodent blood (three studies, n = 40), with a pooled SMD of −0.08 (95 % CI [−1.32, 1.16]).There was a large increase in biomarkers for oxidized DNA bases in rodent plasma (two studies, n = 38) with a pooled SMD of 2.25 (95 % CI [1.27, 3.24]).Gonads: There was an increase in biomarkers for oxidized DNA bases in the rodent testis (two studies, n = 24) with a pooled SMD of 1.60 (95 % CI [0.62, 2.59]).The effect of RF-EMF on biomarkers for modified proteins and amino acids in the ovary of rodents (two studies, n = 52) was inconsistent with a small effect, SMD = 0.24 (95 % CI [−0.74, 1.23])) and a large effect (SMD = 2.08 (95 % CI [1.22, 2.94])).Thymus: RF-EMF increased biomarkers for modified proteins and amino acids in the thymus of rodents (one study, n = 42) considerably with a pooled SMD of 6.16 (95 % CI [3.55, 8.76]).Cells: RF-EMF increased oxidized DNA bases in rodent cells with SMD of 2.49 (95 % CI [1.30, 3.67]) (one study, n = 27). There was a small effect in oxidized lipids (one study, n = 18) but not statistically significant with an SMD of 0.34 (95 % CI [−0.62, 1.29]). In vitro studies In in vitro studies in human cells (three studies, n = 112), there were inconsistent increases in biomarkers for oxidized DNA bases, where the SMDs varied between 0.01 (95 % CI [−0.59, 0.62]) and 7.74 (95 % CI [2.24, 13.24]) in 4 results (2 of them statistically significant). In rodent cells (three studies, n = 24), there was a not statistically significant large effect in biomarkers for oxidized DNA bases with SMD = 2.07 (95 % CI [−1.38, 5.52]).The RF-EMF biomarkers for modified proteins and amino acids in human cells (one study, n = 18) showed a large effect with SMD = 1.07 (95 % CI [−0.05, 2.19]). In rodent cells (two studies, n = 24) a medium effect of SMD = 0.56 (95 % CI [−0.29, 1.41]) was observed. Discussion The evidence on the relation between the exposure to RF-EMF and biomarkers of oxidative stress was of very low certainty, because a majority of the included studies were rated with a high RoB level and provided high heterogeneity. This is due to inaccurate measurements of exposure and/or of measurement of oxidative stress biomarkers and missing information on the blinding of the research personnel. There may be no or an inconsistent effect of RF-EMF on biomarkers of oxidative stress in the brain, liver, blood, plasma and serum, and in the female reproductive system in animal experiments but the evidence is of very low certainty. There may be an increase in biomarkers of oxidative stress in testes, serum and thymus of rodents but the evidence is of very low certainty. Future studies should improve experimental designs and characterization of exposure systems as well as the use of validated biomarker measurements with positive controls.Other: This review was partially funded by the World Health Organization.The protocol for this review is registered in PROSPERO (https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021235573) and published in Environment International (https://doi.org/10.1016/j.envint.2021.106932) (Henschenmacher et al., 2022).

Abstract Metals and metal compounds are essential in daily life. Besides particulate materials nanofibrous material (nanowires) gain importance in innovative processes like optoelectronics. Toxicological data to assess the hazard is often available only for granular metals while data on nanowires is sparse. The project MetalSafety funded by the German BMBF aims at the development of an in vitro model to allow the grouping of different metal compounds with different bioavailability according to their toxicological hazard. Ex vivo and in vivo investigations are used to analyse the predictivity of the in vitro results and the underlying mode-of-action and dose-response relationship. Within this contribution the study concept is introduced. Silver and copper, both in particulate and nanofibrous form, are used across all examinations in vitro, ex vivo and in vivo. To allow an interspecies comparison cell lines derived from human and rat lung are used. Exposure to the materials can be investigated either submerse or with air-liquid-interface (ALI) conditions. The correlation between both species can also be examined ex vivo using precision-cut lung slices (PCLS) derived from human and rat lung tissue. Application in vivo by intratracheal instillation in rats is conducted to enable a validation of the in vitro and ex vivo screening models in a best case scenario under physiological conditions. Comparable endpoints in vitro, ex vivo as well as in vivo are measured during the study. This includes cytotoxicity endpoints and cytokine measurements as well as gene expression analyses. The lung tissue is also subjected to a histopathological examination.

Hazard assessment requires toxicity tests to allow deriving protective points of departure (PoDs) for risk assessment irrespective of a compound's mode of action (MoA). The scope of in vitro test batteries (ivTB) needed to assess systemic toxicity is still unclear. We explored the protectiveness regarding systemic toxicity of an ivTB with a scope that was guided by previous findings from rodent studies, where examining six main targets, including liver and kidney, was sufficient to predict the guideline scope -based PoD with high probability. The ivTB comprises human in vitro models representing liver, kidney, lung, and the neuronal system covering transcriptome, mitochondrial dysfunction, and neuronal outgrowth. Additionally, 32 CALUX (R)- and 10 HepG2 BAC-GFP reporters cover a broad range of disturbance mechanisms. Eight compounds were chosen for causing adverse effects such as immunotoxicity or anemia in vivo, i.e., effects not directly covered by assays in the ivTB. PoDs derived from the ivTB and from oral repeated dose studies in rodents were extrapolated to maximum unbound plasma concentrations for comparison. The ivTB-based PoDs were one to five orders of magnitude lower than in vivo PoDs for six of eight compounds, implying that they were protective. The extent of in vitro response varied across test compounds. Especially for hematotoxic substances, the ivTB showed either no response or only cytotoxicity. Assays better capturing this type of hazard would be needed to complement the ivTB. This study highlights the potentially broad applicability of ivTBs for deriving protective PoDs of compounds with unknown MoA. Plain language summary Animal tests are used to determine how much of a chemical is toxic ("threshold of toxicity") and which organs are affected. In principle, the threshold can also be derived solely from tests with cultured cells. However, only a limited number of cell types can practically be tested, so one challenge is to determine how many and which types shall be tested. In animal tests, only few organs including liver and kidney are regularly among those most sensitively affected. We explored whether a cellbased test battery representing these sensitive organs and covering important mechanisms of toxicity can be used to derive protective human thresholds. To challenge this approach, eight chemicals were tested that primarily cause effects in organs not directly represented in our test battery. Results provided protective thresholds for most of the investigated compounds and gave indications how to further improve the approach towards a full-fledged replacement of animal tests.

This case study explores the applicability of transcriptome data to characterize a common mechanism of action within groups of short-chain aliphatic α-, β-, and γ-diketones. Human reference in vivo data indicate that the α-diketone diacetyl induces bronchiolitis obliterans in workers involved in the preparation of microwave popcorn. The other three α-diketones induced inflammatory responses in preclinical in vivo animal studies, whereas beta and gamma diketones in addition caused neuronal effects. We investigated early transcriptional responses in primary human bronchiolar (PBEC) cell cultures after 24 h and 72 h of air-liquid exposure. Differentially expressed genes (DEGs) were assessed based on transcriptome data generated with the EUToxRisk gene panel of Temp-O-Seq®. For each individual substance, genes were identified displaying a consistent differential expression across dose and exposure duration. The log fold change values of the DEG profiles indicate that α- and β-diketones are more active compared to γ-diketones. α-diketones in particular showed a highly concordant expression pattern, which may serve as a first indication of the shared mode of action. In order to gain a better mechanistic understanding, the resultant DEGs were submitted to a pathway analysis using ConsensusPathDB. The four α-diketones showed very similar results with regard to the number of activated and shared pathways. Overall, the number of signaling pathways decreased from α-to β-to γ-diketones. Additionally, we reconstructed networks of genes that interact with one another and are associated with different adverse outcomes such as fibrosis, inflammation or apoptosis using the TRANSPATH-database. Transcription factor enrichment and upstream analyses with the geneXplain platform revealed highly interacting gene products (called master regulators, MRs) per case study compound. The mapping of the resultant MRs on the reconstructed networks, visualized similar gene regulation with regard to fibrosis, inflammation and apoptosis. This analysis showed that transcriptome data can strengthen the similarity assessment of compounds, which is of particular importance, e.g., in read-across approaches. It is one important step towards grouping of compounds based on biological profiles.

An Extensive Literature Search (ELS) to collect and identify all studies published since 2010 and relevant to the topic mineral oil hydrocarbons in combination with the substance group characterisation, occurrence in food and toxicity was performed in the three databases PubMed, Web of Science and SciFinder® for six Areas. After combination of the searches from the three databases and removal of the duplicates, the total number of references is 2504. The evaluation of all retrieved references for relevance by screening the title and abstract and applying eligibility criteria (inclusion/exclusion) resulted in a total number of relevant references for Area 1 of 55, for Area 2 of 27, for Area 3 of 15, for Area 4 of 21 for Area 5 of 1 and for Area 6 of 6. The total number of relevant references was 93. However, for the substance group POH no relevant reference was identified. Additionally, there are 4 references additionally, which could not be clearly assigned.

BACKGROUND:Oxidative stress is conjectured to be related to many diseases. Furthermore, it is hypothesized that radiofrequency fields may induce oxidative stress in various cell types and thereby compromise human and animal health. This systematic review (SR) aims to summarize and evaluate the literature related to this hypothesis. OBJECTIVES:The main objective of this SR is to evaluate the associations between the exposure to radiofrequency electromagnetic fields and oxidative stress in experimental models (in vivo and in vitro). METHODS:The SR framework has been developed following the guidelines established in the WHO Handbook for Guideline Development and the Handbook for Conducting a Literature-Based Health Assessment). We will include controlled in vivo and in vitro laboratory studies that assess the effects of an exposure to RF-EMF on valid markers for oxidative stress compared to no or sham exposure. The protocol is registered in PROSPERO. We will search the following databases: PubMed, Embase, Web of Science Core Collection, Scopus, and the EMF-Portal. The reference lists of included studies and retrieved review articles will also be manually searched. STUDY APPRAISAL AND SYNTHESIS METHOD:Data will be extracted according to a pre-defined set of forms developed in the DistillerSR online software and synthesized in a meta-analysis when studies are judged sufficiently similar to be combined. If a meta-analysis is not possible, we will describe the effects of the exposure in a narrative way. RISK OF BIAS:The risk of bias will be assessed with the NTP/OHAT risk of bias rating tool for human and animal studies. We will use GRADE to assess the certainty of the conclusions (high, moderate, low, or inadequate) regarding the association between radiofrequency electromagnetic fields and oxidative stress. FUNDING:This work was funded by the World Health Organization (WHO). REGISTRATION:The protocol was registered on the PROSPERO webpage on July 8, 2021.

This report evaluates the training courses delivered under the contract OC/EFSA/SCER/2017/01 - Lot 1. Within the period of January 2018 to February 2022 a total of 21 training courses were provided, eight on-site training courses in Parma at EFSA, six virtual training courses during the Covid-19 pandemic and seven eLearning courses comprising various numbers of modules. The courses covered different aspects of chemical and biological risk assessment and related tools, namely i) harmonisation of risk assessment methodologies for human health and ecological risk assessment of combined exposure to multiple chemicals (mixture assessment), ii) risk assessment of the application of nanoscience and nanotechnologies in agro/food/feed (nanotoxicity); iii) science-based criteria for identifying endocrine disruptors in the context of EU legislation on pesticides and biocides (endocrine disruption); iv) principles on genotoxicity on scientific assessment (genotoxicity) and v) computational toxicology approaches and tools (in silico). All tutors were experts in their field and had previously performed training courses on these topics. The target participants of the training courses were members of EFSA’s Scientific Committee/Panels and their working groups as well as employees from national and international regulatory agencies associated with risk assessment of feed and food compounds. Members of the EFSA Networks as well as EFSA scientific staff also participated in the training courses. Courses were evaluated based on the feedback of participants and continuously improved also by integrating updated or new EFSA guidance documents.

The article contains sections titled: 1 Introduction 2 Endocrine System 3 Endocrine Mechanism 4 Test Methods 4.1 OECD Conceptual Framework 4.2 New Testing and Screening Methods 5 Natural and Synthetic Endocrine Disruptors 5.1 Estrogens 5.2 Phytohormones 5.3 17α-Ethinylestradiol 5.4 Alkylphenols 5.5 Phthalates 5.6 Bisphenol A 5.7 Dioxins 5.8 Polychlorinated Biphenyls 5.9 Tributyltin 6 Toxicology and Regulatory Affairs 6.1 Biocides 6.2 Pesticides 6.3 Medicinal Products 6.3.1 Humans 6.3.2 Animals 6.4 Food and Feed 6.5 Cosmetics References