Anna Beronius

Facilitating the use of non-standard in vivo studies in health risk assessment of chemicals: a proposal to improve evaluation criteria and reporting

To improve data availability in health risk assessment of chemicals and fill information gaps there is a need to facilitate the use of non‐standard toxicity studies, i.e. studies not conducted according to any standardized toxicity test guidelines. The purpose of this work was to propose criteria and guidance for the evaluation of reliability and relevance of non‐standard in vivo studies, which could be used to facilitate systematic and transparent evaluation of such studies for health risk assessment. Another aim was to propose user friendly guidance for reporting of non‐standard studies intended to promote an improvement in reporting of studies that could be of use in risk assessment. Requirements and recommendations for the design and execution of in vivo toxicity studies were identified from The Organisation for Economic Co‐operation and Development (OECD) test guidelines, and served as basis for the data evaluation criteria and reporting guidelines. Feedback was also collected from experts within the field of toxicity testing and risk assessment and used to construct a two‐tiered framework for study evaluation, as well as refine the reporting guidelines. The proposed framework emphasizes the importance of study relevance and an important aspect is to not completely dismiss studies from health risk assessment based on very strict criteria for reliability. The suggested reporting guidelines provide researchers with a tool to fulfill reporting requirements as stated by regulatory agencies. Together, these resources provide an approach to include all relevant data that may fill information gaps and reduce scientific uncertainty in health risk assessment conclusions, and subsequently also in chemical policy decisions. Copyright

The influence of study design and sex-differences on results from developmental neurotoxicity studies of bisphenol A: implications for toxicity testing.

Developmental neurotoxicity (DNT) of bisphenol A (BPA) has been investigated in a large number of studies. However, there are discrepancies in the results reported between the studies. The aim of this study was to identify and analyze factors that may contribute to these differences and to assess whether there are sex-differences in the sensitivity of certain endpoints or tests used in DNT-studies. Forty-four DNT studies of BPA were identified from the open literature. Details about study design and results from each study, as well as the criteria for DNT testing according to the standardized OECD test guideline (TG) 426, were collected in a database. This enabled systematic and detailed comparisons between studies as well as to the criteria and recommendations stated in TG 426. Multivariate analyses were also used to investigate how different factors of the study design contributed to differences in study results. The analyses showed behavioral effects were often observed for endpoints that are not required according to OECD TG 426, such as anxiety-related, social and sexual behaviors, especially at very low doses and in female offspring. On the other hand relatively few studies observed any effects on motor activity, which is commonly used in screening for neurotoxic effects in regulatory testing. However, varied and to some extent seemingly contradictory results have been reported in these studies, especially for endpoints related to motor activity and anxiety and exploration. Many studies were also poorly reported, limiting these analyses. No strong conclusions could be drawn from the multivariate analyses. A few factors of study design, such as the size of the dose and number of dose levels used and the use of litter or individual pup as statistical unit seemed to have some influence on study results. In conclusion, this analysis suggests that DNT-studies conducted according to the standardized OECD TG 426 may overlook sensitive effects of BPA, and possibly other potential endocrine disruptors, especially in female offspring.

A proposed framework for the systematic review and integrated assessment (SYRINA) of endocrine disrupting chemicals.

BackgroundThe issue of endocrine disrupting chemicals (EDCs) is receiving wide attention from both the scientific and regulatory communities. Recent analyses of the EDC literature have been criticized for failing to use transparent and objective approaches to draw conclusions about the strength of evidence linking EDC exposures to adverse health or environmental outcomes. Systematic review methodologies are ideal for addressing this issue as they provide transparent and consistent approaches to study selection and evaluation. Objective methods are needed for integrating the multiple streams of evidence (epidemiology, wildlife, laboratory animal, in vitro, and in silico data) that are relevant in assessing EDCs.MethodsWe have developed a framework for the systematic review and integrated assessment (SYRINA) of EDC studies. The framework was designed for use with the International Program on Chemical Safety (IPCS) and World Health Organization (WHO) definition of an EDC, which requires appraisal of evidence regarding 1) association between exposure and an adverse effect, 2) association between exposure and endocrine disrupting activity, and 3) a plausible link between the adverse effect and the endocrine disrupting activity.ResultsBuilding from existing methodologies for evaluating and synthesizing evidence, the SYRINA framework includes seven steps: 1) Formulate the problem; 2) Develop the review protocol; 3) Identify relevant evidence; 4) Evaluate evidence from individual studies; 5) Summarize and evaluate each stream of evidence; 6) Integrate evidence across all streams; 7) Draw conclusions, make recommendations, and evaluate uncertainties. The proposed method is tailored to the IPCS/WHO definition of an EDC but offers flexibility for use in the context of other definitions of EDCs.ConclusionsWhen using the SYRINA framework, the overall objective is to provide the evidence base needed to support decision making, including any action to avoid/minimise potential adverse effects of exposures. This framework allows for the evaluation and synthesis of evidence from multiple evidence streams. Finally, a decision regarding regulatory action is not only dependent on the strength of evidence, but also the consequences of action/inaction, e.g. limited or weak evidence may be sufficient to justify action if consequences are serious or irreversible.

Health risk assessment procedures for endocrine disrupting compounds within different regulatory frameworks in the European Union.

In this study we have investigated how different regulatory frameworks in Europe cope with identification and risk assessment of endocrine disrupting compounds (EDCs). Four regulatory groups were selected for the investigation: existing industrial chemicals, environmental pollutants in food, pharmaceuticals and plant protection products. The legislation and guidelines for each of these groups were scrutinized and compared in detail. In addition, one recent European risk assessment document each for three identified EDCs, i.e. bisphenol A, dioxins and vinclozolin, were reviewed and compared. We found that the requirements for toxicity testing and availability and scope of risk assessment guidelines varied between the four regulatory frameworks. Also, the general principles regarding the human relevance of the mode of action identified in animal tests differed in the different risk assessments. In conclusion, there is little conformity in the risk assessment processes between these groups of chemicals. Because of the complicated nature of endocrine disruption, test methods, principles and criteria for data interpretation traditionally used might not be directly applicable to EDCs and further development of a transparent and reliable risk assessment process for this type of substances is needed.

Science in Risk Assessment and Policy (SciRAP): An Online Resource for Evaluating and Reporting In Vivo (Eco)Toxicity Studies

ABSTRACT (Eco)toxicity studies conducted according to internationally standardized test guidelines are often considered reliable by default and preferred as key evidence in regulatory risk assessment. At the same time regulatory agencies emphasize the use of all relevant (eco)toxicity data in the risk assessment process, including non-standard studies. However, there is a need to facilitate the use of such studies in regulatory risk assessment. Therefore, we propose a framework that facilitates a systematic and transparent evaluation of the reliability and relevance of (eco)toxicity in vivo studies for health and environmental risk assessment. The framework includes specific criteria to guide study evaluation, as well as a color-coding tool developed to aid the application of these criteria. In addition we provide guidance intended for researchers on how to report non-standard studies to ensure that they meet regulatory requirements. The intention of the evaluating and reporting criteria is to increase the usability of all relevant data that may fill information gaps in chemical risk assessments. The framework is publically available online, free of charge, at the Science in Risk Assessment and Policy (SciRAP) website: www.scirap.org. The aim of this article is to present the framework and resources available at the SciRAP website.

Using systematic reviews for hazard and risk assessment of endocrine disrupting chemicals

The possibility that endocrine disrupting chemicals (EDCs) in our environment contribute to hormonally related effects and diseases observed in human and wildlife populations has caused concern among decision makers and researchers alike. EDCs challenge principles traditionally applied in chemical risk assessment and the identification and assessment of these compounds has been a much debated topic during the last decade. State of the science reports and risk assessments of potential EDCs have been criticized for not using systematic and transparent approaches in the evaluation of evidence. In the fields of medicine and health care, systematic review methodologies have been developed and used to enable objectivity and transparency in the evaluation of scientific evidence for decision making. Lately, such approaches have also been promoted for use in the environmental health sciences and risk assessment of chemicals. Systematic review approaches could provide a tool for improving the evaluation of evidence for decision making regarding EDCs, e.g. by enabling systematic and transparent use of academic research data in this process. In this review we discuss the advantages and challenges of applying systematic review methodology in the identification and assessment of EDCs.

Weight of evidence evaluation and systematic review in EU chemical risk assessment: Foundation is laid but guidance is needed.

The aim of this review was to investigate if and how the application of weight of evidence (WoE) evaluation or systematic review (SR) in chemical risk assessment is promoted within different regulatory frameworks in the European Union. Legislative and relevant guidance documents within nine regulatory frameworks were scrutinized and compared. WoE evaluation or SR is promoted in seven of the investigated frameworks but sufficient guidance for how to perform these processes is generally lacking. None of the investigated frameworks give enough guidance for generating robust and reproducible WoE evaluations or SRs. In conclusion, the foundation for use of WoE evaluation and SR is laid in the majority of the investigated frameworks, but there is a need to provide more structured and detailed guidance. In order to make the process of developing guidance as efficient as possible, and to ensure smooth transfer of risk assessments between frameworks if a chemical is risk assessed both as, for example, a biocide and an industrial chemical, it is recommended that guidance is developed jointly by the European regulatory agencies.

Bridging the gap between academic research and regulatory health risk assessment of Endocrine Disrupting Chemicals.

Regulatory risk assessment is traditionally based primarily on toxicity studies conducted according to standardized and internationally validated test guidelines. However, health risk assessment of endocrine disrupting chemicals (EDCs) is argued to rely on the efficient integration of findings from academic research. The aim of this review was to provide an overview of current developments to facilitate the use of academic research in regulatory risk assessment of chemicals and how certain aspects of study design and reporting are particularly important for the risk assessment process. By bridging the gap between academic research and regulatory health risk assessment of EDCs, scientific uncertainty in risk assessment conclusions can be reduced, allowing for better targeted policy decisions for chemical risk reduction.

Transparency of chemical risk assessment data under REACH

The REACH regulation requires EU manufacturers and importers of substances to register information on the hazard and risk of their substances with the European Chemicals Agency (ECHA). Risk management of the substances is based on the provided information. It is known that conclusions on hazard and risk are influenced by expert judgements as well as potential conflict of interests. Thus, it is important that hazard and risk assessments are transparent and can be evaluated by a third party. The aim of this study is to scrutinize the transparency, i.e. the accessibility and comprehensibility, of information on substances registered under REACH. Data on repeated dose toxicity and hazard assessment conclusions were extracted for 60 substances from the REACH registration database available on the ECHA website. The data were compiled in a database for systematically evaluating the transparency of information related to the conclusions on hazard or risk. In addition, chemical safety reports (CSR) were requested from ECHA for five substances. The transparency of information on the hazard and risk of substances was found to be limited for several reasons. First, certain information was removed due to confidentiality and certain fields were not published because they could contain confidential information although the information had not been claimed confidential. Also, the extent to which registrants reported information varied, and the presentation of some data and certain terminology required further clarification. In addition, the data source for the majority of the key and supporting studies could not be identified due to confidentiality. Since registrants are only required to summarise studies, it cannot be verified whether all relevant information from non-public industry reports have been reported. Lastly, certain information related to the hazard and risk assessment were only reported in the CSR which is only available upon request; a time-consuming and work-intensive process. As information on registered chemicals is currently provided to the public, it is difficult to follow steps that are undertaken in the hazard and risk assessment. This limits the possibility for a third party to evaluate the assessment.

Combining web-based tools for transparent evaluation of data for risk assessment: developmental effects of bisphenol A on the mammary gland as a case study.

Different tools have been developed that facilitate systematic and transparent evaluation and handling of toxicity data in the risk assessment process. The present paper sets out to explore the combined use of two web‐based tools for study evaluation and identification of reliable data relevant to health risk assessment. For this purpose, a case study was performed using in vivo toxicity studies investigating low‐dose effects of bisphenol A on mammary gland development. The reliability of the mammary gland studies was evaluated using the Science in Risk Assessment and Policy (SciRAP) criteria for toxicity studies. The Health Assessment Workspace Collaborative (HAWC) was used for characterizing and visualizing the mammary gland data in terms of type of effects investigated and reported, and the distribution of these effects within the dose interval. It was then investigated whether there was any relationship between study reliability and the type of effects reported and/or their distribution in the dose interval. The combination of the SciRAP and HAWC tools allowed for transparent evaluation and visualization of the studies investigating developmental effects of BPA on the mammary gland. The use of these tools showed that there were no apparent differences in the type of effects and their distribution in the dose interval between the five studies assessed as most reliable and the whole data set. Combining the SciRAP and HAWC tools was found to be a useful approach for evaluating in vivo toxicity studies and identifying reliable and sensitive information relevant to regulatory risk assessment of chemicals. Copyright