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

A UK framework for the assessment and integration of different scientific evidence streams in chemical risk assessment

BACKGROUND

Few methods are available for transparently combining different evidence streams for chemical risk assessment to reach an integrated conclusion on the probability of causation. Hence, the UK Committees on Toxicity (COT) and on Carcinogenicity (COC) have reviewed current practice and developed guidance on how to achieve this in a transparent manner, using graphical visualisation.

METHODS/APPROACH

All lines of evidence, including toxicological, epidemiological, new approach methodologies, and mode of action should be considered, taking account of their strengths/weaknesses in their relative weighting towards a conclusion on the probability of causation. A qualitative estimate of the probability of causation is plotted for each line of evidence and a combined estimate provided.

DISCUSSION/CONCLUSIONS

Guidance is provided on integration of multiple lines of evidence for causation, based on current best practice. Qualitative estimates of probability for each line of evidence are plotted graphically. This ensures a deliberative, consensus conclusion on likelihood of causation is reached. It also ensures clear communication of the influence of the different lines of evidence on the overall conclusion on causality. Issues on which advice from the respective Committees is sought varies considerably, hence the guidance is designed to be sufficiently flexible to meet this need.

A framework for integrating evidence to assess hazards and risk

To accurately characterize human health hazards, human, animal, and mechanistic data must be integrated and the relevance to the research question of all three lines of evidence must be considered. Mechanistic data are often critical to the full integration of animal and human data and to characterizing relevance and uncertainty. This novel evidence integration framework (EIF) provides a method for synthesizing data from comprehensive, systematic, quality-based assessments of the epidemiological and toxicological literature, including in vivo and in vitro mechanistic studies. It organizes data according to both the observed human health effects and the mechanism of action of the chemical, providing a method to support evidence synthesis. The disease-based component uses the evidence of human health outcomes studied in the best quality epidemiological literature to organize the toxicological data according to authors' stated purpose, with the pathophysiology of the disease determining the potential relevance of the toxicological data. The mechanism-based component organizes the data based on the proposed mechanisms of effect and data supporting events leading to each endpoint, with the epidemiological data potentially providing corroborating information. The EIF includes a method to cross-classify and describe the concordance of the data, and to characterize its uncertainty. At times, the two methods of organizing the data may lead to different conclusions. This facilitates identification of knowledge gaps and shows the impact of uncertainties on the strength of causal inference.

Systems for rating bodies of evidence used in systematic reviews of air pollution exposure and reproductive and children's health: a methodological survey

BACKGROUND

Translating findings from systematic reviews assessing associations between environmental exposures and reproductive and children's health into policy recommendations requires valid and transparent evidence grading.

METHODS

We aimed to evaluate systems for grading bodies of evidence used in systematic reviews of environmental exposures and reproductive/ children's health outcomes, by conducting a methodological survey of air pollution research, comprising a comprehensive search for and assessment of all relevant systematic reviews. To evaluate the frameworks used for rating the internal validity of primary studies and for grading bodies of evidence (multiple studies), we considered whether and how specific criteria or domains were operationalized to address reproductive/children's environmental health, e.g., whether the timing of exposure assessment was evaluated with regard to vulnerable developmental stages.

RESULTS

Eighteen out of 177 (9.8%) systematic reviews used formal systems for rating the body of evidence; 15 distinct internal validity assessment tools for primary studies, and nine different grading systems for bodies of evidence were used, with multiple modifications applied to the cited approaches. The Newcastle Ottawa Scale (NOS) and the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) framework, neither developed specifically for this field, were the most commonly used approaches for rating individual studies and bodies of evidence, respectively. Overall, the identified approaches were highly heterogeneous in both their comprehensiveness and their applicability to reproductive/children's environmental health research.

CONCLUSION

Establishing the wider use of more appropriate evidence grading methods is instrumental both for strengthening systematic review methodologies, and for the effective development and implementation of environmental public health policies, particularly for protecting pregnant persons and children.

Applying a modified systematic review and integrated assessment framework (SYRINA) - a case study on triphenyl phosphate

This work presents a case study in applying a systematic review framework (SYRINA) to the identification of chemicals as endocrine disruptors. The suitability and performance of the framework is tested with regard to the widely accepted World Health Organization definition of an endocrine disruptor (ED). The endocrine disrupting potential of triphenyl phosphate (TPP), a well-studied flame retardant reported to exhibit various endocrine related effects was assessed. We followed the 7 steps of the SYRINA framework, articulating the research objective via Populations, Exposures, Comparators, Outcomes (PECO) statements, performed literature search and screening, conducted study evaluation, performed data extraction and summarized and integrated the evidence. Overall, 66 studies, consisting of in vivo, in vitro and epidemiological data, were included. We concluded that triphenyl phosphate could be identified as an ED based on metabolic disruption and reproductive function. We found that the tools used in this case study and the optimizations performed on the framework were suitable to assess properties of EDs. A number of challenges and areas for methodological development in systematic appraisal of evidence relating to endocrine disrupting potential were identified; significant time and effort were needed for the analysis of in vitro mechanistic data in this case study, thus increasing the workload and time needed to perform the systematic review process. Further research and development of this framework with regards to grey literature (non-peer-reviewed literature) search, harmonization of study evaluation methods, more consistent evidence integration approaches and a pre-defined method to assess links between adverse effect and endocrine activity are recommended. It would also be advantageous to conduct more case studies for a chemical with less data than TPP.

Endocrine-disrupting chemicals: Mainstream recognition of health effects and implications for the practicing internist

Rapidly advancing evidence documents that a broad array of synthetic chemicals found ubiquitously in the environment contribute to disease and disability across the lifespan. Although the early literature focused on early life exposures, endocrine-disrupting chemicals (EDCs) are now understood to contribute substantially to chronic disease in adulthood, especially metabolic, cardiovascular, and reproductive consequences as well as endocrine cancers. The contribution to mortality is substantial, with over 90,000 deaths annually and at least $39 billion/year in lost economic productivity in the United States (US) due to exposure to certain phthalates that are used as plasticizers in food packaging. Importantly, exposures are disproportionately high in low-income and minoritized populations, driving disparities in these conditions. Though non-Hispanic Blacks and Mexican Americans comprise 12.6% and 13.5% of the US population, they bear 16.5% and 14.6% of the disease burden due to EDCs, respectively. Many of these exposures can be modified through safe and simple behavioral changes supported by proactive government action to both limit known hazardous exposures and to proactively screen new industrial chemicals prior to their use. Routine healthcare maintenance should include guidance to reduce EDC exposures, and a recent report by the Institute of Medicine suggests that testing be conducted, particularly in populations heavily exposed to perfluoroalkyl substances-chemicals used in nonstick coatings as well as oil- and water-resistant clothing.

Frameworks for screening and risk management of chemicals and advanced materials: A critical review

Despite the evolution over the last half century of regulatory programs and frameworks developed for the evaluation of safety and management of risks associated with chemicals and materials, new and emerging contaminant issues continue to be identified. These recurring issues suggest a need for review and reflection on current approaches and strategies for ensuring the safety of chemicals and materials. Twelve existing frameworks relating to the evaluation and management of chemical or material risk were reviewed to identify potential process improvements for facilitating early identification of potentially problematic substances and better inform risk management strategies (e.g., prohibition, restricted use, or selection of safer alternatives). The frameworks were selected to represent a broad spectrum of regional, national, and international authorities and purposes, including preproduction evaluation of new substances, classification and hazard communication, identification of persistent pollutants, and identification of safer alternatives. Elements common to the frameworks were identified, as well as features unique to select frameworks. A comparative evaluation was performed, and potential new strategies and approaches were identified to inform process improvement recommendations. These recommendations include requiring validated analytical procedures to enable measurement in environmental media, improved data transparency and accessibility, flexibility to incorporate advances into the state of the practice (e.g., new approach methodologies and high-throughput assessment tools), and incorporation of monitoring and adaptive management strategies to enable more timely intervention. Process improvement recommendations are discussed and summarized in a conceptual risk management framework. Integr Environ Assess Manag 2023;19:1192-1206. © 2022 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC). This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Prenatal exposure to ambient air pollutants and congenital heart defects: An umbrella review

BACKGROUND

Prenatal exposure to ambient air pollutants has been linked to congenital heart defects (CHD), but findings of existing systematic reviews have been mixed.

OBJECTIVE

To assess the epidemiological evidence on associations between prenatal exposure to ambient air pollutants and CHD subtypes, based on a systematic overview of reviews ("umbrella review").

METHODS

We conducted a systematic search for reviews assessing associations between prenatal exposure to criteria air pollutants and CHD. The risk of bias was evaluated using the Risk of Bias in Systematic Reviews (ROBIS) tool. The certainty of the systematic review findings was graded using the Navigation Guide methodology.

RESULTS

We identified eleven systematic reviews, including eight with meta-analyses, assessing in total 35 primary studies of prenatal exposure to criteria air pollutants and various CHD subtypes. The certainty of the findings of four meta-analyses indicating an increased risk for coarctation of the aorta associated with nitrogen dioxide exposure was rated as moderate. The certainty of findings indicating positive, inverse, or null associations for other pollutant-subtype combinations was rated as very low to low, based on low precision and high statistical heterogeneity of summary odds ratios (SOR), substantial inconsistencies between review findings, and methodological limitations of the systematic reviews.

DISCUSSION

The inconsistent findings and high statistical heterogeneity of many SOR of the included systematic reviews may partly be traced to differences in methodological approaches, and the risk of bias across included reviews (e.g., inclusion criteria, systematic search strategies, synthesis methods) and primary studies (e.g., exposure assessment, diagnostic criteria). Adherence to appropriate systematic review guidelines for environmental health research, as well as rigorous evaluation of risk of bias in primary studies, are essential for future risk assessments and policy-making. Still, our findings suggest that prenatal exposure to ambient air pollutants may increase risks for at least some CHD subtypes.

Research advances in identification procedures of endocrine disrupting chemicals

Endocrine disrupting chemicals (EDCs) are increasingly concerned substance endangering human health and environment. However, there is no unified standard for identifying chemicals as EDCs, which is also controversial internationally. In this review, the procedures for EDC identification in different organizations/countries were described. Importantly, three aspects to be considered in identifying chemical substances as EDCs were summarized, which were mechanistic data, animal experiments, and epidemiological information. The relationships between them were also discussed. To elaborate more clearly on these three aspects of evidence, scientific data on some chemicals including bisphenol A, 1,2-dibromo-4-(1,2 dibromoethyl) cyclohexane and perchlorate were collected and evaluated. Altogether, the above three chemicals were assessed for interfering with hormones and elaborated their health hazards from macroscopic to microscopic. This review is helpful for standardizing the identification procedure of EDCs.

Understanding target-specific effects of antidepressant drug pollution on molluscs: A systematic review protocol

BACKGROUND

The environmental prevalence of widely prescribed human pharmaceuticals that target key evolutionary conserved biomolecules present across phyla is concerning. Antidepressants, one of the most widely consumed pharmaceuticals globally, have been developed to target biomolecules modulating monoaminergic neurotransmission, thus interfering with the endogenous regulation of multiple key neurophysiological processes. Furthermore, rising prescription and consumption rates of antidepressants caused by the burgeoning incidence of depression is consistent with increasing reports of antidepressant detection in aquatic environments worldwide. Consequently, there are growing concerns that long-term exposure to environmental levels of antidepressants may cause adverse drug target-specific effects on non-target aquatic organisms. While these concerns have resulted in a considerable body of research addressing a range of toxicological endpoints, drug target-specific effects of environmental levels of different classes of antidepressants in non-target aquatic organisms remain to be understood. Interestingly, evidence suggests that molluscs may be more vulnerable to the effects of antidepressants than any other animal phylum, making them invaluable in understanding the effects of antidepressants on wildlife. Here, a protocol for the systematic review of literature to understand drug target-specific effects of environmental levels of different classes of antidepressants on aquatic molluscs is described. The study will provide critical insight needed to understand and characterize effects of antidepressants relevant to regulatory risk assessment decision-making, and/or direct future research efforts.

METHODS

The systematic review will be conducted in line with the guidelines by the Collaboration for Environmental Evidence (CEE). A literature search on Scopus, Web of Science, PubMed, as well as grey literature databases, will be carried out. Using predefined criteria, study selection, critical appraisal and data extraction will be done by multiple reviewers with a web-based evidence synthesis platform. A narrative synthesis of outcomes of selected studies will be presented. The protocol has been registered in the Open Science Framework (OSF) registry with the registration DOI: 10.17605/OSF.IO/P4H8W.

Weight of evidence for cross-species conservation of androgen receptor-based biological activity

The U.S. Environmental Protection Agency's Endocrine Disruptor Screening Program (EDSP) is tasked with assessing chemicals for their potential to perturb endocrine pathways, including those controlled by androgen receptor (AR). To address challenges associated with traditional testing strategies, EDSP is considering in vitro high-throughput screening assays to screen and prioritize chemicals more efficiently. The ability of these assays to accurately reflect chemical interactions in nonmammalian species remains uncertain. Therefore, a goal of the EDSP is to evaluate how broadly results can be extrapolated across taxa. To assess the cross-species conservation of AR-modulated pathways, computational analyses and systematic literature review approaches were used to conduct a comprehensive analysis of existing in silico, in vitro, and in vivo data. First, molecular target conservation was assessed across 585 diverse species based on the structural similarity of ARs. These results indicate that ARs are conserved across vertebrates and are predicted to share similarly susceptibility to chemicals that interact with the human AR. Systematic analysis of over 5000 published manuscripts was used to compile in vitro and in vivo cross-species toxicity data. Assessment of in vitro data indicates conservation of responses occurs across vertebrate ARs, with potential differences in sensitivity. Similarly, in vivo data indicate strong conservation of the AR signaling pathways across vertebrate species, although sensitivity may vary. Overall, this study demonstrates a framework for utilizing bioinformatics and existing data to build weight of evidence for cross-species extrapolation and provides a technical basis for extrapolating hAR-based data to prioritize hazard in nonmammalian vertebrate species.

Endocrine Disruptor Chemicals and Children's Health

We are all exposed to endocrine-disrupting chemicals (EDCs) starting from embryonic life. The fetus and child set up crucial developmental processes allowing adaptation to the environment throughout life: they are extremely sensitive to very low doses of hormones and EDCs because they are developing organisms. Considering the developmental origin of well-being and diseases, every adult organism expresses consequences of the environment in which it developed. The molecular mechanisms through which the main EDCs manifest their effects and their potential association with endocrine disorders, such as diabetes, obesity, thyroid disease and alteration of adrenal hormones, will be reviewed here. Despite 40 years having passed since the first study on EDCs, little is yet known about them; therefore, our purpose is to take stock of the situation to establish a starting point for further studies. Since there is plenty of evidence showing that exposure to EDCs may adversely impact the health of adults and children through altered endocrine function-suggesting their link to endocrinopathies-it is essential in this context to bear in mind what is already known about endocrine disruptors and to deepen our knowledge to establish rules of conduct aimed at limiting exposure to EDCs' negative effects. Considering that during the COVID-19 pandemic an increase in endocrine disruptor effects has been reported, it will also be useful to address this new phenomenon for better understanding its basis and limiting its consequences.

Unlocking India's Potential in Managing Endocrine-Disrupting Chemicals (EDCs): Importance, Challenges, and Opportunities

Endocrine-disrupting chemicals (EDCs) are a prime concern for the environment and health globally. Research shows that in developing countries such as India both the environment and human populations are severely exposed to EDCs and consequently experience rising incidents of adverse health effects such as diabetes and cancers. In this paper, we discuss the current EDC management approach in India, critically assess its limitations, and describe opportunities for potential improvements. Foremost, current EDC management actions and interventions in India are fragmented and outdated, and far behind the modern and comprehensive approaches adopted in the European Union and other developed countries. Strong and well-planned actions are required on various fronts of science, policy, commerce, and public engagement. These actions include the adoption of a dedicated and modern regulatory framework for managing EDCs, enhancing capacity and infrastructure for EDC monitoring in the environment and human population, employing public-private partnership programs for not only managing EDCs but also in the sectors that indirectly contribute toward the mismanagement of EDCs in the country, and raising awareness on EDCs and promoting health-preserving consumption habits among the public. As India hosts a large proportion of the global human population and biodiversity, the success or failure of its actions will substantially affect the direction of global efforts to manage EDCs and set an example for other developing countries.

Conducting evaluations of evidence that are transparent, timely and can lead to health-protective actions

BACKGROUND

In February 2021, over one hundred scientists and policy experts participated in a web-based Workshop to discuss the ways that divergent evaluations of evidence and scientific uncertainties are used to delay timely protection of human health and the environment from exposures to hazardous agents. The Workshop arose from a previous workshop organized by the European Environment Agency (EEA) in 2008 and which also drew on case studies from the EEA reports on 'Late Lessons from Early Warnings' (2001, 2013). These reports documented dozens of hazardous agents including many chemicals, for which risk reduction measures were delayed for decades after scientists and others had issued early and later warnings about the harm likely to be caused by those agents.

RESULTS

Workshop participants used recent case studies including Perfluorooctanoic acid (PFOA), Extremely Low Frequency - Electrical Magnetic Fields (ELF-EMF fields), glyphosate, and Bisphenol A (BPA) to explore myriad reasons for divergent outcomes of evaluations, which has led to delayed and inadequate protection of the public's health. Strategies to overcome these barriers must, therefore, at a minimum include approaches that 1) Make better use of existing data and information, 2) Ensure timeliness, 3) Increase transparency, consistency and minimize bias in evidence evaluations, and 4) Minimize the influence of financial conflicts of interest.

CONCLUSION

The recommendations should enhance the production of "actionable evidence," that is, reliable evaluations of the scientific evidence to support timely actions to protect health and environments from exposures to hazardous agents. The recommendations are applicable to policy and regulatory settings at the local, state, federal and international levels.

Assessing the quality of evidence in studies estimating prevalence of exposure to occupational risk factors: The QoE-SPEO approach applied in the systematic reviews from the WHO/ILO Joint Estimates of the Work-related burden of disease and Injury

BACKGROUND

The World Health Organization (WHO) and the International Labour Organization (ILO) have produced the WHO/ILO Joint Estimates of the Work-related Burden of Disease and Injury (WHO/ILO Joint Estimates). For these, systematic reviews of studies estimating the prevalence of exposure to selected occupational risk factors have been conducted to provide input data for estimations of the number of exposed workers. A critical part of systematic review methodology is to assess the quality of evidence across studies. In this article, we present the approach applied in these WHO/ILO systematic reviews for performing such assessments on studies of prevalence of exposure. It is called the Quality of Evidence in Studies estimating Prevalence of Exposure to Occupational risk factors (QoE-SPEO) approach. We describe QoE-SPEO's development to date, demonstrate its feasibility reporting results from pilot testing and case studies, note its strengths and limitations, and suggest how QoE-SPEO should be tested and developed further.

METHODS

Following a comprehensive literature review, and using expert opinion, selected existing quality of evidence assessment approaches used in environmental and occupational health were reviewed and analysed for their relevance to prevalence studies. Relevant steps and components from the existing approaches were adopted or adapted for QoE-SPEO. New steps and components were developed. We elicited feedback from other systematic review methodologists and exposure scientists and reached consensus on the QoE-SPEO approach. Ten individual experts pilot-tested QoE-SPEO. To assess inter-rater agreement, we counted ratings of expected (actual and non-spurious) heterogeneity and quality of evidence and calculated a raw measure of agreement (P_i) between individual raters and rater teams for the downgrade domains. P_i ranged between 0.00 (no two pilot testers selected the same rating) and 1.00 (all pilot testers selected the same rating). Case studies were conducted of experiences of QoE-SPEO's use in two WHO/ILO systematic reviews.

RESULTS

We found no existing quality of evidence assessment approach for occupational exposure prevalence studies. We identified three relevant, existing approaches for environmental and occupational health studies of the effect of exposures. Assessments using QoE-SPEO comprise three steps: (1) judge the level of expected heterogeneity (defined as non-spurious variability that can be expected in exposure prevalence, within or between individual persons, because exposure may change over space and/or time), (2) assess downgrade domains, and (3) reach a final rating on the quality of evidence. Assessments are conducted using the same five downgrade domains as the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach: (a) risk of bias, (b) indirectness, (c) inconsistency, (d) imprecision, and (e) publication bias. For downgrade domains (c) and (d), the assessment varies depending on the level of expected heterogeneity. There are no upgrade domains. The QoE-SPEO's ratings are "very low", "low", "moderate", and "high". To arrive at a final decision on the overall quality of evidence, the assessor starts at "high" quality of evidence and for each domain downgrades by one or two levels for serious concerns or very serious concerns, respectively. In pilot tests, there was reasonable agreement in ratings for expected heterogeneity; 70% of raters selected the same rating. Inter-rater agreement ranged considerably between downgrade domains, both for individual rater pairs (range P_i: 0.36-1.00) and rater teams (0.20-1.00). Sparse data prevented rigorous assessment of inter-rater agreement in quality of evidence ratings.

CONCLUSIONS

We present QoE-SPEO as an approach for assessing quality of evidence in prevalence studies of exposure to occupational risk factors. It has been developed to its current version (as presented here), has undergone pilot testing, and was applied in the systematic reviews for the WHO/ILO Joint Estimates. While the approach requires further testing and development, it makes steps towards filling an identified gap, and progress made so far can be used to inform future work in this area.

Innovation in regulatory approaches for endocrine disrupting chemicals: The journey to risk assessment modernization in Canada

Globally, regulatory authorities grapple with the challenge of assessing the hazards and risks to human and ecosystem health that may result from exposure to chemicals that disrupt the normal functioning of endocrine systems. Rapidly increasing number of chemicals in commerce, coupled with the reliance on traditional, costly animal experiments for hazard characterization - often with limited sensitivity to many important mechanisms of endocrine disruption -, presents ongoing challenges for chemical regulation. The consequence is a limited number of chemicals for which there is sufficient data to assess if there is endocrine toxicity and hence few chemicals with thorough hazard characterization. To address this challenge, regulatory assessment of endocrine disrupting chemicals (EDCs) is benefiting from a revolution in toxicology that focuses on New Approach Methodologies (NAMs) to more rapidly identify, prioritize, and assess the potential risks from exposure to chemicals using novel, more efficient, and more mechanistically driven methodologies and tools. Incorporated into Integrated Approaches to Testing and Assessment (IATA) and guided by conceptual frameworks such as Adverse Outcome Pathways (AOPs), emerging approaches focus initially on molecular interactions between the test chemical and potentially vulnerable biological systems instead of the need for animal toxicity data. These new toxicity testing methods can be complemented with in silico and computational toxicology approaches, including those that predict chemical kinetics. Coupled with exposure data, these will inform risk-based decision-making approaches. Canada is part of a global network collaborating on building confidence in the use of NAMs for regulatory assessment of EDCs. Herein, we review the current approaches to EDC regulation globally (mainly from the perspective of human health), and provide a perspective on how the advances for regulatory testing and assessment can be applied and discuss the promises and challenges faced in adopting these novel approaches to minimize risks due to EDC exposure in Canada, and our world.

Assessor burden, inter-rater agreement and user experience of the RoB-SPEO tool for assessing risk of bias in studies estimating prevalence of exposure to occupational risk factors: An analysis from the WHO/ILO Joint Estimates of the Work-related Burden of Disease and Injury

BACKGROUND

As part of the development of the World Health Organization (WHO)/International Labour Organization (ILO) Joint Estimates of the Work-related Burden of Disease and Injury, WHO and ILO carried out several systematic reviews to determine the prevalence of exposure to selected occupational risk factors. Risk of bias assessment for individual studies is a critical step of a systematic review. No tool existed for assessing the risk of bias in prevalence studies of exposure to occupational risk factors, so WHO and ILO developed and pilot tested the RoB-SPEO tool for this purpose. Here, we investigate the assessor burden, inter-rater agreement, and user experience of this new instrument, based on the abovementioned WHO/ILO systematic reviews.

METHODS

Twenty-seven individual experts applied RoB-SPEO to assess risk of bias. Four systematic reviews provided a total of 283 individual assessments, carried out for 137 studies. For each study, two or more assessors independently assessed risk of bias across the eight RoB-SPEO domains selecting one of RoB-SPEO's six ratings (i.e., "low", "probably low", "probably high", "high", "unclear" or "cannot be determined"). Assessors were asked to report time taken (i.e. indicator of assessor burden) to complete each assessment and describe their user experience. To gauge assessor burden, we calculated the median and inter-quartile range of times taken per individual risk of bias assessment. To assess inter-rater reliability, we calculated a raw measure of inter-rater agreement (Pi) for each RoB-SPEO domain, between Pi = 0.00, indicating no agreement and Pi = 1.00, indicating perfect agreement. As subgroup analyses, Pi was also disaggregated by systematic review, assessor experience with RoB-SPEO (≤10 assessments versus > 10 assessments), and assessment time (tertiles: ≤25 min versus 26-66 min versus ≥ 67 min). To describe user experience, we synthesised the assessors' comments and recommendations.

RESULTS

Assessors reported a median of 40 min to complete one assessment (interquartile range 21-120 min). For all domains, raw inter-rater agreement ranged from 0.54 to 0.82. Agreement varied by systematic review and assessor experience with RoB-SPEO between domains, and increased with increasing assessment time. A small number of users recommended further development of instructions for selected RoB-SPEO domains, especially bias in selection of participants into the study (domain 1) and bias due to differences in numerator and denominator (domain 7).

DISCUSSION

Overall, our results indicated good agreement across the eight domains of the RoB-SPEO tool. The median assessment time was comparable to that of other risk of bias tools, indicating comparable assessor burden. However, there was considerable variation in time taken to complete assessments. Additional time spent on assessments may improve inter-rater agreement. Further development of the RoB-SPEO tool could focus on refining instructions for selected RoB-SPEO domains and additional testing to assess agreement for different topic areas and with a wider range of assessors from different research backgrounds.

Molecular Changes in the Dorsal Root Ganglion during the Late Phase of Peripheral Nerve Injury-induced Pain in Rodents: A Systematic Review

The dorsal root ganglion is widely recognized as a potential target to treat chronic pain. A fundamental understanding of quantitative molecular and genomic changes during the late phase of pain is therefore indispensable. The authors performed a systematic literature review on injury-induced pain in rodent dorsal root ganglions at minimally 3 weeks after injury. So far, slightly more than 300 molecules were quantified on the protein or messenger RNA level, of which about 60 were in more than one study. Only nine individual sequencing studies were performed in which the most up- or downregulated genes varied due to heterogeneity in study design. Neuropeptide Y and galanin were found to be consistently upregulated on both the gene and protein levels. The current knowledge regarding molecular changes in the dorsal root ganglion during the late phase of pain is limited. General conclusions are difficult to draw, making it hard to select specific molecules as a focus for treatment.

Endocrine disrupting chemicals and COVID-19 relationships: A computational systems biology approach

BACKGROUND

Patients at high risk of severe forms of COVID-19 frequently suffer from chronic diseases, but other risk factors may also play a role. Environmental stressors, such as endocrine disrupting chemicals (EDCs), can contribute to certain chronic diseases and might aggravate the course of COVID-19.

OBJECTIVES

To explore putative links between EDCs and COVID-19 severity, an integrative systems biology approach was constructed and applied.

METHODS

As a first step, relevant data sets were compiled from major data sources. Biological associations of major EDCs to proteins were extracted from the CompTox database. Associations between proteins and diseases known as important COVID-19 comorbidities were obtained from the GeneCards and DisGeNET databases. Based on these data, we developed a tripartite network (EDCs-proteins-diseases) and used it to identify proteins overlapping between the EDCs and the diseases. Signaling pathways for common proteins were then investigated by over-representation analysis.

RESULTS

We found several statistically significant pathways that may be dysregulated by EDCs and that may also be involved in COVID-19 severity. The Th17 and the AGE/RAGE signaling pathways were particularly promising.

CONCLUSIONS

Pathways were identified as possible targets of EDCs and as contributors to COVID-19 severity, thereby highlighting possible links between exposure to environmental chemicals and disease development. This study also documents the application of computational systems biology methods as a relevant approach to increase the understanding of molecular mechanisms linking EDCs and human diseases, thereby contributing to toxicology prediction.

Systematic Review Methodologies and Endocrine Disrupting Chemicals: Improving Evaluations of the Plastic Monomer Bisphenol A

BACKGROUND

Endocrine disrupting chemicals (EDCs) are found in plastics, personal care products, household items, and other consumer goods. Risk assessments are intended to characterize a chemical's hazards, identify the doses at which adverse outcomes are observed, quantify exposure levels, and then compare these doses to determine the likelihood of risk in a given population. There are many problems with risk assessments for EDCs, allowing people to be exposed to levels that are later associated with serious health outcomes in epidemiology studies.

OBJECTIVE

In this review, we examine issues that affect the evaluation of EDCs in risk assessments (e.g., use of insensitive rodent strains and absence of disease-oriented outcomes in hazard assessments; inadequate exposure assessments). We then review one well-studied chemical, Bisphenol A (BPA; CAS #80-05-7) an EDC found in plastics, food packaging, and other consumer products. More than one hundred epidemiology studies suggest associations between BPA exposures and adverse health outcomes in environmentally exposed human populations.

FINDINGS

We present support for the use of systematic review methodologies in the evaluation of BPA and other EDCs. Systematic reviews would allow studies to be evaluated for their reliability and risk of bias. They would also allow all data to be used in risk assessments, which is a requirement for some regulatory agencies.

CONCLUSION

Systematic review methodologies can be used to improve evaluations of BPA and other EDCs. Their use could help to restore faith in risk assessments and ensure that all data are utilized in decision-making. Regulatory agencies are urged to conduct transparent, well-documented and proper systematic reviews for BPA and other EDCs.

REPRODUCTIVE TOXICOLOGY: Endocrine disruption and reproductive disorders: impacts on sexually dimorphic neuroendocrine pathways

We are all living with hundreds of anthropogenic chemicals in our bodies every day, a situation that threatens the reproductive health of present and future generations. This review focuses on endocrine-disrupting compounds (EDCs), both naturally occurring and man-made, and summarizes how they interfere with the neuroendocrine system to adversely impact pregnancy outcomes, semen quality, age at puberty, and other aspects of human reproductive health. While obvious malformations of the genitals and other reproductive organs are a clear sign of adverse reproductive health outcomes and injury to brain sexual differentiation, the hypothalamic-pituitary-gonadal (HPG) axis can be much more difficult to discern, particularly in humans. It is well-established that, over the course of development, gonadal hormones shape the vertebrate brain such that sex-specific reproductive physiology and behaviors emerge. Decades of work in neuroendocrinology have elucidated many of the discrete and often very short developmental windows across pre- and postnatal development in which this occurs. This has allowed toxicologists to probe how EDC exposures in these critical windows can permanently alter the structure and function of the HPG axis. This review includes a discussion of key EDC principles including how latency between exposure and the emergence of consequential health effects can be long, along with a summary of the most common and less well-understood EDC modes of action. Extensive examples of how EDCs are impacting human reproductive health, and evidence that they have the potential for multi-generational physiological and behavioral effects are also provided.

Reviews in environmental health: How systematic are they?

BACKGROUND

Synthesizing environmental health science is crucial to taking action to protect public health. Procedures for evidence evaluation and integration are transitioning from "expert-based narrative" to "systematic" review methods. However, little is known about the methodology being utilized for either type of review.

OBJECTIVES

To appraise the methodological strengths and weaknesses of a sample of "expert-based narrative" and "systematic" reviews in environmental health.

METHODS

We conducted a comprehensive search of multiple databases and identified relevant reviews using pre-specified eligibility criteria. We applied a modified version of the Literature Review Appraisal Toolkit (LRAT) to three environmental health topics that assessed the utility, validity and transparency of reviews.

RESULTS

We identified 29 reviews published between 2003 and 2019, of which 13 (45%) were self-identified as systematic reviews. Across every LRAT domain, systematic reviews received a higher percentage of "satisfactory" ratings compared to non-systematic reviews. In eight of these domains, there was a statistically significant difference observed between the two types of reviews and "satisfactory" ratings. Non-systematic reviews performed poorly with the majority receiving an "unsatisfactory" or "unclear" rating in 11 of the 12 domains. Systematic reviews performed poorly in six of the 12 domains; 10 (77%) did not state the reviews objectives or develop a protocol; eight (62%) did not state the roles and contribution of the authors, or evaluate the internal validity of the included evidence consistently using a valid method; and only seven (54%) stated a pre-defined definition of the evidence bar on which their conclusions were based, or had an author disclosure of interest statement.

DISCUSSION

Systematic reviews produced more useful, valid, and transparent conclusions compared to non-systematic reviews, but poorly conducted systematic reviews were prevalent. Ongoing development and implementation of empirically based systematic review methods are required in environmental health to ensure transparent and timely decision making to protect the public's health.

Endocrine disrupting chemicals (EDCs) and the neuroendocrine system: Beyond estrogen, androgen, and thyroid

Hundreds of anthropogenic chemicals occupy our bodies, a situation that threatens the health of present and future generations. This chapter focuses on endocrine disrupting compounds (EDCs), both naturally occurring and man-made, that affect the neuroendocrine system to adversely impact health, with an emphasis on reproductive and metabolic pathways. The neuroendocrine system is highly sexually dimorphic and essential for maintaining homeostasis and appropriately responding to the environment. Comprising both neural and endocrine components, the neuroendocrine system is hormone sensitive throughout life and touches every organ system in the body. The integrative nature of the neuroendocrine system means that EDCs can have multi-system effects. Additionally, because gonadal hormones are essential for the sex-specific organization of numerous neuroendocrine pathways, endocrine disruption of this programming can lead to permanent deficits. Included in this review is a brief history of the neuroendocrine disruption field and a thorough discussion of the most common and less well understood neuroendocrine disruption modes of action. Also provided are extensive examples of how EDCs are likely contributing to neuroendocrine disorders such as obesity, and evidence that they have the potential for multi-generational effects.

An approach to classifying occupational exposures to endocrine disrupting chemicals by sex hormone function using an expert judgment process

Endocrine disrupting chemicals (EDCs) are exogenous substances that interfere with the endocrine system and cause adverse effects. We aimed to classify the effects of 24 known EDCs, prevalent in certain occupations, according to four modes of action (estrogenic, antiestrogenic, androgenic, and/or antiandrogenic). A literature search, stratified into four types of literature was conducted (namely: national and international agency reports; review articles; primary studies; ToxCast^TM). The state of the evidence of each EDC on sex hormone function was summarized and reviewed by an expert panel. For each mode of action, the experts evaluated the likelihood of endocrine disruption in five categories: "No", "Unlikely", "Possibly", "Probably", and "Yes". Seven agents were categorized as "Yes," or having strong evidence for their effects on sex hormone function (antiandrogenic: lead, arsenic, butylbenzyl phthalate, dibutyl phthalate, dicyclohexyl phthalate; estrogenic: nonylphenol, bisphenol A). Nine agents were categorized as "Probable," or having probable evidence (antiandrogenic: bis(2-ethylhexyl)phthalate, nonylphenol, toluene, bisphenol A, diisononyl phthalate; androgenic: cadmium; estrogenic: copper, cadmium and; anti-estrogenic: lead). Two agents (arsenic, polychlorinated biphenyls) had opposing conclusions supporting both "probably" estrogenic and antiestrogenic effects. This synthesis will allow researchers to evaluate the health effects of selected EDCs with an added level of precision related to the mode of action.

Towards guidelines for time-trend reviews examining temporal variability in human biomonitoring data of pollutants

In the last few decades, a plethora of studies have focused on human biomonitoring (HBM) of chemical pollutants. Reviewing the copious HBM data reported in these studies is essential for evaluating the effectiveness of pollution management efforts, for example by evaluating time-trends. Nevertheless, guidance to systematically evaluate time trends in published HBM data has never been developed. In this study, we therefore present a proposal for guidelines to conduct "time-trend reviews" (TTRs) that examine time trends in published large HBM datasets of chemical pollutant concentrations. We also demonstrate the applicability of these guidelines through a case study that assesses time-trends in global and regional HBM data on mercury. The recommended TTR guidelines in this study are divided into seven steps: formulating the objective of the TTR, setting up of eligibility criteria, defining search strategy and screening of literature, screening results of search, extracting data, analysing data, and assessing certainty, including the potential for bias in the evidence base. The TTR guidelines proposed in this study are straightforward and less complex than those for conducting systematic reviews assessing datasets on potential human health effects of exposure to pollutants or medical interventions. These proposed guidelines are intended to enable the credible, transparent, and reproducible conduct of TTRs.

A Survey of Systematic Evidence Mapping Practice and the Case for Knowledge Graphs in Environmental Health and Toxicology

Systematic evidence mapping offers a robust and transparent methodology for facilitating evidence-based approaches to decision-making in chemicals policy and wider environmental health (EH). Interest in the methodology is growing; however, its application in EH is still novel. To facilitate the production of effective systematic evidence maps for EH use cases, we survey the successful application of evidence mapping in other fields where the methodology is more established. Focusing on issues of “data storage technology,” “data integrity,” “data accessibility,” and “transparency,” we characterize current evidence mapping practice and critically review its potential value for EH contexts. We note that rigid, flat data tables and schema-first approaches dominate current mapping methods and highlight how this practice is ill-suited to the highly connected, heterogeneous, and complex nature of EH data. We propose this challenge is overcome by storing and structuring data as “knowledge graphs.” Knowledge graphs offer a flexible, schemaless, and scalable model for systematically mapping the EH literature. Associated technologies, such as ontologies, are well-suited to the long-term goals of systematic mapping methodology in promoting resource-efficient access to the wider EH evidence base. Several graph storage implementations are readily available, with a variety of proven use cases in other fields. Thus, developing and adapting systematic evidence mapping for EH should utilize these graph-based resources to ensure the production of scalable, interoperable, and robust maps to aid decision-making processes in chemicals policy and wider EH.

Assessment of the endocrine disrupting properties of bisphenol AF: a case study applying the European regulatory criteria and guidance

BACKGROUND

Scientific criteria to identify endocrine disruptors (ED) was recently implemented for plant protection products (PPP) and biocidal products (BP). A guidance document has been published by ECHA and EFSA in the context of ED criteria for PPPs and BPs.

METHODS

In the present work, a case study was performed on Bisphenol AF (BPAF) to explore the application of the EU criteria and EFSA/ECHA guidance document for the ED assessment of a non-pesticide chemical regulated under REACH. A data dossier was built by a systematic literature search (Web of Science, Pubmed, Embase; n = 511), title/abstract screening (n = 124) and full text examination (n = 88). All the information was extracted and systematically reported for 309 parameters (100 for adversity; 209 for endocrine activity). The reliability of studies was assessed (SciRAP tool).

RESULTS

Data were synthesized into 96 lines of evidence for adversity (n = 57), and endocrine activity (n = 39); and assessed by weight of evidence methodology. The initial analysis of the evidence indicated EATS-mediated adversity in mammals, therefore a mode of action (MoA) was postulated for both male and female adult exposure. Female MoA included estrogen receptor activation and altered steroidogenesis leading to ovarian dysfunction, altered estrous cycling and impaired female fertility. Male MoA was initiated by androgen receptor inhibition and altered steroidogenesis leading to dysfunction of male reproductive organs and impaired male fertility.

CONCLUSIONS

The overall conclusion of the ED assessment indicated that BPAF meets the ED criteria for human health. The steps described in the ED guidance document were successfully completed, resulting in a thorough, structured and transparent identification of BPAF as an ED. Advantages and limitations of applying the ED criteria and guidance for a REACH chemical are discussed.

Serum bisphenol A analogues in women diagnosed with the polycystic ovary syndrome - is there an association?

Due to the endocrine disrupting effects of bisphenol A (BPA) several governmental authorities have banned its use and the manufacturers had to find alternative substances with similar chemical properties. This led to the increase in the use of so-called BPA analogues, which however also turn out to possess mild estrogenic and ani-androgenic properties and thus, may cause fertility problems and sex-hormone dependent endocrinopathies. The aim of this study was to evaluate the potential association between the exposure to BPA and its two analogues: BPS and BPF, with the diagnosis of the polycystic ovary syndrome (PCOS), which remains the most common female endocrinopathy. Serum concentrations of BPA, BPS and BPF were measured using high performance liquid chromatography method with tandem mass spectrometry (HPLC-MS/MS) among 199 women with PCOS and 158 control subjects. In women with PCOS serum BPS concentrations were significantly higher compared to the control subjects (geometric mean [95% CI]: 0.14 ng/mL [0.10; 1.17] vs. 0.08 ng/mL [0.06; 0.09], P = 0.023). Serum BPA and BPF concentrations did not differ between the studied groups. There was however a negative correlation between serum BPA and HOMA-IR (r = - 0.233, P = 0.001) and TST (r = - 0.203, P = 0.006) in women with PCOS. No correlations were found between the serum BPs and other metabolic parameters such as serum lipids, insulin, DHEA-S, androstenedione and FAI. When studying the association between serum BPA analogues and PCOS it turned out that women whose serum BPS concentrations were in the first tertile were more likely to be diagnosed with this endocrinopathy (OR [95% CI]: 1.21 [1.04; 3.46], P = 0.017). This association was also statistically significant when adjusted for age, education, BMI, smoking, income, and alcohol consumption (adjusted OR [95% CI]: 1.12 [1.03; 3.71], P = 0.029). These results point to the potential association between the exposure to BPS and the diagnosis of PCOS. The role of BPA is not clear and warrants further studies.

Agrochemicals with estrogenic endocrine disrupting properties: Lessons Learned?

Many agrochemicals have endocrine disrupting properties. A subset of these chemicals is characterized as "estrogenic". In this review, we describe several distinct ways that chemicals used in crop production can affect estrogen signaling. Using three agrochemicals as examples (DDT, endosulfan, and atrazine), we illustrate how screening tests such as the US EPA's EDSP Tier 1 assays can be used as a first-pass approach to evaluate agrochemicals for endocrine activity. We then apply the "Key Characteristics" approach to illustrate how chemicals like DDT can be evaluated, together with the World Health Organization's definition of an endocrine disruptor, to identify data gaps. We conclude by describing important issues that must be addressed in the evaluation and regulation of hormonally active agrochemicals including mixture effects, efforts to reduce vertebrate animal use, chemical prioritization, and improvements in hazard, exposure, and risk assessments.

Facilitation of risk assessment with evidence-based methods - A framework for use of systematic mapping and systematic reviews in determining hazard, developing toxicity values, and characterizing uncertainty

Systematic review tools and approaches developed for clinical medicine are often difficult to apply "off the shelf" in order to meet the needs of chemical risk assessments. To address such, we propose an approach that can be used by practitioners for using evidence-based methods to facilitate the risk assessment process. The framework builds on and combines efforts conducted to date by a number of agencies and researchers; the novelty is in combining these efforts with a practical understanding of risk assessment, and translating such into a 'step-by-step' guide. The approach relies on three key components: problem formulation, systematic evidence mapping, and systematic review, applied using a stepwise approach. Unique to this framework is the consideration of exposure in selecting, prioritizing, and evaluating data (e.g., dose-relevance, routes of exposure, etc.). Using the proposed step-by-step process, critical appraisal of individual studies (e.g., formal and structured assessment of both relevance and reliability) and integration efforts are considered in context of specified risk assessment objectives (e.g., mode of action, dose-response) as well as chemical-specific considerations. The resulting framework provides a logical approach of how evidence-based methods can be used to facilitate risk assessment, and elevates the use of systematic methods beyond hazard identification to directly facilitating transparent and objective selection of candidate studies and/or datasets used to quantitatively characterize risk, and to better use the underlying process to inform the approaches used to develop toxicity values.

Mitigation strategies to fight the COVID-19 pandemic—present, future and beyond

Purpose

The latest novel coronavirus disease 2019 (COVID-19) pandemic continues to have a significant social and financial impact globally. It is very essential to study, categorize and systematize published research on mitigation strategies adopted during previous pandemic scenario that could provide an insight into improving the current crisis. The goal of this paper is to systematize and identify gaps in previous research and suggest potential recommendations as a conceptual framework from a strategic point of view.

Design/methodology/approach

A systematic review of Scopus and Web of Science (WoS) core collection databases was performed based on strict keyword search selections followed by a bibliometric meta-analysis of the final dataset.

Findings

This study indicated that the traditional mitigation techniques adopted during past pandemics are in place but are not capable of managing the transmission capability and virulence of COVID-19. There is a greater need for rethinking and re-engineering short and long-term approaches to prevent, control and contain the current pandemic situation.

Practical implications

Integrating various mitigation approaches shall assist in flattening the pandemic curve and help in the long run.

Originality/value

Articles, conference proceedings, books, book chapters and other references from two extensive databases (Scopus and WoS) were purposively considered for this study. The search was confined to the selected keywords outlined in the methodology section of this paper.

Endocrine-disrupting chemicals: implications for human health

Since reports published in 2015 and 2016 identified 15 probable exposure-outcome associations, there has been an increase in studies in humans of exposure to endocrine-disrupting chemicals (EDCs) and a deepened understanding of their effects on human health. In this Series paper, we have reviewed subsequent additions to the literature and identified new exposure-outcome associations with substantial human evidence. Evidence is particularly strong for relations between perfluoroalkyl substances and child and adult obesity, impaired glucose tolerance, gestational diabetes, reduced birthweight, reduced semen quality, polycystic ovarian syndrome, endometriosis, and breast cancer. Evidence also exists for relations between bisphenols and adult diabetes, reduced semen quality, and polycystic ovarian syndrome; phthalates and prematurity, reduced anogenital distance in boys, childhood obesity, and impaired glucose tolerance; organophosphate pesticides and reduced semen quality; and occupational exposure to pesticides and prostate cancer. Greater evidence has accumulated than was previously identified for cognitive deficits and attention-deficit disorder in children following prenatal exposure to bisphenol A, organophosphate pesticides, and polybrominated flame retardants. Although systematic evaluation is needed of the probability and strength of these exposure-outcome relations, the growing evidence supports urgent action to reduce exposure to EDCs.

Endocrine-disrupting chemicals: economic, regulatory, and policy implications

Endocrine-disrupting chemicals (EDCs) substantially cost society as a result of increases in disease and disability but-unlike other toxicant classes such as carcinogens-have yet to be codified into regulations as a hazard category. This Series paper examines economic, regulatory, and policy approaches to limit human EDC exposures and describes potential improvements. In the EU, general principles for EDCs call for minimisation of human exposure, identification as substances of very high concern, and ban on use in pesticides. In the USA, screening and testing programmes are focused on oestrogenic EDCs exclusively, and regulation is strictly risk-based. Minimisation of human exposure is unlikely without a clear overarching definition for EDCs and relevant pre-marketing test requirements. We call for a multifaceted international programme (eg, modelled on the International Agency for Research in Cancer) to address the effects of EDCs on human health-an approach that would proactively identify hazards for subsequent regulation.

Endocrine disrupting chemicals and COVID-19 relationships: a computational systems biology approach

Background

Patients at high risk of severe forms of COVID-19 frequently suffer from chronic diseases, but other risk factors may also play a role. Environmental stressors, such as endocrine disrupting chemicals (EDCs), can contribute to certain chronic diseases and might aggravate the course of COVID-19.

Objectives

To explore putative links between EDCs and COVID-19 severity, an integrative systems biology approach was constructed and applied.

Methods

As a first step, relevant data sets were compiled from major data sources. Biological associations of major EDCs to proteins were extracted from the CompTox database. Associations between proteins and diseases known as important COVID-19 comorbidities were obtained from the GeneCards and DisGeNET databases. Based on these data, we developed a tripartite network (EDCs-proteins-diseases) and used it to identify proteins overlapping between the EDCs and the diseases. Signaling pathways for common proteins were then investigated by over-representation analysis.

Results

We found several statistically significant pathways that may be dysregulated by EDCs and that may also be involved in COVID-19 severity. The Th17 and the AGE/RAGE signaling pathways were particularly promising.

Conclusions

Pathways were identified as possible targets of EDCs and as contributors to COVID-19 severity, thereby highlighting possible links between exposure to environmental chemicals and disease development. This study also documents the application of computational systems biology methods as a relevant approach to increase the understanding of molecular mechanisms linking EDCs and human diseases, thereby contributing to toxicology prediction.

How Frequently Do We Touch Facial T-Zone: A Systematic Review

Background

Researchers across the world are emphasising the importance of hand-washing and limited touching of face to curb the spread of COVID-19. However, access to safe water and hygiene is inadequate in many places around the globe; hence T-zone touching restriction is considered more worthwhile compared to other prevention strategies.

Aim

A systematic review was carried out to appraise the frequency of T-zone (eyes, nose, mouth, chin) touching in humans to comprehend the challenge of its restriction, and thus support public health professionals to produce evidence synthesis guidance for public.For this systemic review, data were collected by keyword searching, and several online databases were searched. The PRISMA checklist, PECO protocol and STROBE guideline were followed in this review, and pooled data were analysed in R version 4.

Result

Total of 10 single arms observational studies were included. The pooled average (SD) facial self-touch per hour was 50.06 (±47) times, and a specific touch of T-zone was 68.7 (±27). T-zone self-touch within the total facial self-touch was found higher R = 0.680, with 95% CI 0.14, 0.91, P = 0.02 and X2 = 167.63, P < 0.0001.

Conclusion

The review found that face-touch is a type of consistent regulatory movements. Control of T-zone touch requires extensive behaviour intervention and community awareness.

Bisphenol A shapes children's brain and behavior: towards an integrated neurotoxicity assessment including human data

Concerns about the effects of bisphenol A (BPA) on human brain and behavior are not novel; however, Grohs and colleagues have contributed groundbreaking data on this topic in a recent issue of Environmental Health. For the first time, associations were reported between prenatal BPA exposure and differences in children's brain microstructure, which appeared to mediate the association between this exposure and children's behavioral symptoms. Findings in numerous previous mother-child cohorts have pointed in a similar worrying direction, linking higher BPA exposure during pregnancy to more behavioral problems throughout childhood as assessed by neuropsychological questionnaires. Notwithstanding, this body of work has not been adequately considered in risk assessment. From a toxicological perspective, results are now available from the CLARITY-BPA consortium, designed to reconcile academic and regulatory toxicology findings. In fact, the brain has consistently emerged as one of the most sensitive organs disrupted by BPA, even at doses below those considered safe by regulatory agencies such as the European Food Safety Authority (EFSA). In this Commentary, we contextualize the results of Grohs et al. within the setting of previous epidemiologic and CLARITY-BPA data and express our disquiet about the "all-or-nothing" criterion adopted to select human data in a recent EFSA report on the appraisal methodology for their upcoming BPA risk assessment. We discuss the most relevant human studies, identify emerging patterns, and highlight the need for adequate assessment and interpretation of the increasing epidemiologic literature in this field in order to support decision-making. With the aim of avoiding a myopic or biased selection of a few studies in traditional risk assessment procedures, we propose a future reevaluation of BPA focused on neurotoxicity and based on a systematic and comprehensive integration of available mechanistic, animal, and human data. Taken together, the experimental and epidemiologic evidence converge in the same direction: BPA is a probable developmental neurotoxicant at low doses. Accordingly, the precautionary principle should be followed, progressively implementing stringent preventive policies worldwide, including the banning of BPA in food contact materials and thermal receipts, with a focus on the utilization of safer substitutes.

Acting on uncertainty: real-life mixtures of endocrine disrupting chemicals

Exposure to multiple synthetic chemicals is a permanent feature of modern life. Many of these chemicals are suspected to disrupt endocrine systems of humans and animals. Endocrine disrupting chemicals (EDCs) act at very low concentrations and non-linearly, defying mainstream single-substance chemical regulation. Here we provide an analysis of findings from the first phase of the European Horizon2020-funded “EDC-MixRisk” project as a case of contemporary life-science enterprise, which addresses health-risks related to real-life exposure to mixtures of EDCs. Real-life EDC mixtures were inferred in the project from biological samples taken from pregnant women in a large epidemiological study that followed up their children over several years across major health domains; responses to these mixtures were then experimentally identified, and based on these findings, mixture risk assessment models were developed. The project consequently advocated for European chemical regulation more attentive to real-life exposure. Locating it within historical and sociological analyses of chemical exposure and within the European chemical political context, we argue that scientific uncertainty related to real-life EDC mixture exposure enables a form of epistemological approach and scientific activism, simultaneously in continuity with, and in break from, mainstream toxicology. In a chemically polluted world, this kind of science still occupies a place in the tension between public health and market-oriented regulation.

Reconnaissance of Surface Water Estrogenicity and the Prevalence of Intersex in Smallmouth Bass (Micropterus Dolomieu) Inhabiting New Jersey

The observation of testicular oocytes in male fishes has been utilized as a biomarker of estrogenic endocrine disruption. A reconnaissance project led in the Northeastern United States (US) during the period of 2008–2010 identified a high prevalence of intersex smallmouth bass on or near US Fish & Wildlife Service National Wildlife Refuges that included the observation of 100% prevalence in smallmouth bass males collected from the Wallkill River, NJ, USA. To better assess the prevalence of intersex smallmouth bass across the state of New Jersey, a tiered reconnaissance approach was initiated during the fall of 2016. Surface water samples were collected from 101 (85 river, 16 lake/reservoir) sites across the state at base-flow conditions for estrogenicity bioassay screening. Detectable estrogenicity was observed at 90% of the sites and 64% were above the US Environmental Protection Agency trigger level of 1 ng/L. Median surface water estrogenicity was 1.8 ng/L and a maximum of 6.9 ng/L E2Eq_BLYES was observed. Adult smallmouth bass were collected from nine sites, pre-spawn during the spring of 2017. Intersex was identified in fish at all sites, and the composite intersex prevalence was 93.8%. Prevalence across sites ranged from 70.6% to 100%. In addition to intersex, there was detectable plasma vitellogenin in males at all sites. Total estrogenicity in surface water was determined at these fish collection sites, and notable change over time was observed. Correlation analysis indicated significant positive correlations between land use (altered land; urban + agriculture) and surface water estrogenicity. There were no clear associations between land use and organismal metrics of estrogenic endocrine disruption (intersex or vitellogenin). This work establishes a baseline prevalence of intersex in male smallmouth bass in the state of New Jersey at a limited number of locations and identifies a number of waterbodies with estrogenic activity above an effects-based threshold.

OECD approaches and considerations for regulatory evaluation of endocrine disruptors

Identifying the potential endocrine disruptor hazard of environmental chemicals is a regulatory mandate for many countries. However, due to the adaptive nature of the endocrine system, absence of a single method capable of identifying endocrine disruption, and the latency between exposure to endocrine disrupting chemical during sensitive life stages and the manifestation of adverse responses, satisfying the regulatory requirement needed to identify a chemical as an endocrine disruptor is a challenge. There are now a variety of validated regulatory tests that can be used in combination to provide evidence that a chemical affects the oestrogen, androgen, thyroid, and steroidogenic pathways of vertebrates, but most rely (at least to some extent) on animal testing and require considerable cost and time to produce the necessary data. Emerging research methods are able to evaluate other endocrine pathways, incorporate more sensitive endpoints, and combine multiple alternative methods to predict in vivo outcomes. Some research approaches may also bridge gaps that have been identified in current endocrine regulatory testing. For the near term, considering new endpoints in a regulatory context may require adding them to existing test methods in order to establish relationships between the traditional and the innovative. From the outset, endocrine testing has always required integration of multiple methods that provide data on different levels of biological organisation, thus, the area of endocrine disruption is particularly adaptable to adverse outcome pathway (AOP) frameworks and integrated test methods built around AOPs. Herein, we provide a review of the status of endocrine disruptors in the OECD context, examples where innovation from research is needed to improve or bridge gaps in endocrine testing, and suggestions for regulators and researchers to facilitate uptake of innovate methods for endocrine disruptor regulatory testing. The increase in several human complex human disorders that include an endocrine component and the alarming decrease in wildlife biodiversity are commanding directives to include the best, most informative, innovative approaches to accelerate the rate and throughput of chemical evaluation for endocrine disruption.

RoB-SPEO: A tool for assessing risk of bias in studies estimating the prevalence of exposure to occupational risk factors from the WHO/ILO Joint Estimates of the Work-related Burden of Disease and Injury

BACKGROUND

The World Health Organization (WHO) and the International Labour Organization (ILO) are developing joint estimates of the work-related burden of disease and injury (WHO/ILO Joint Estimates). For this, systematic reviews of studies estimating the prevalence of exposure to selected occupational risk factors will be conducted to provide input data for estimations of the number of exposed workers. A critical part of systematic review methods is to assess risk of bias (RoB) of individual studies. In this article, we present and describe the development of such a tool, called the Risk of Bias in Studies estimating Prevalence of Exposure to Occupational risk factors (RoB-SPEO) tool; report results from RoB-SPEO's pilot testing; note RoB-SPEO's limitations; and suggest how the tool might be tested and developed further.

METHODS

Selected existing RoB tools used in environmental and occupational health systematic reviews were reviewed and analysed. From existing tools, we identified domains for the new tool and, if necessary, added new domains. For each domain, we then identified and integrated components from the existing tools (i.e. instructions, domains, guiding questions, considerations, ratings and rating criteria), and, if necessary, we developed new components. Finally, we elicited feedback from other systematic review methodologists and exposure scientists and agreed upon RoB-SPEO. Nine experts pilot tested RoB-SPEO, and we calculated a raw measure of inter-rater agreement (Pi) for each of its domain, rating Pi < 0.4 as poor, 0.4 ≤ Pi ≥ 0.8 as substantial and Pi > 0.80 as almost perfect agreement.

RESULTS

Our review found no standard tool for assessing RoB in prevalence studies of exposure to occupational risk factors. We identified six existing tools for environmental and occupational health systematic reviews and found that their components for assessing RoB differ considerably. With the new RoB-SPEO tool, assessors judge RoB for each of eight domains: (1) bias in selection of participants into the study; (2) bias due to a lack of blinding of study personnel; (3) bias due to exposure misclassification; (4) bias due to incomplete exposure data; (5) bias due to conflict of interest; (6) bias due to selective reporting of exposures; (7) bias due to difference in numerator and denominator; and (8) other bias. The RoB-SPEO's ratings are low, probably low, probably high, high or no information. Pilot testing of the RoB-SPEO tool found substantial inter-rater agreement for six domains (range of Pi for these domains: 0.51-0.80), but poor agreement for two domains (i.e. Pi of 0.31 and 0.33 for biases due to incomplete exposure data and in selection of participants into the study, respectively). Limitations of RoB-SPEO include that it has not yet been fully performance-tested.

CONCLUSIONS

We developed the RoB-SPEO tool for assessing RoB in prevalence studies of exposure to occupational risk factors. The tool will be applied and its performance tested in the ongoing systematic reviews for the WHO/ILO Joint Estimates.

The IARC Monographs: Updated Procedures for Modern and Transparent Evidence Synthesis in Cancer Hazard Identification

The Monographs produced by the International Agency for Research on Cancer (IARC) apply rigorous procedures for the scientific review and evaluation of carcinogenic hazards by independent experts. The Preamble to the IARC Monographs, which outlines these procedures, was updated in 2019, following recommendations of a 2018 expert advisory group. This article presents the key features of the updated Preamble, a major milestone that will enable IARC to take advantage of recent scientific and procedural advances made during the 12 years since the last Preamble amendments. The updated Preamble formalizes important developments already being pioneered in the Monographs program. These developments were taken forward in a clarified and strengthened process for identifying, reviewing, evaluating, and integrating evidence to identify causes of human cancer. The advancements adopted include the strengthening of systematic review methodologies; greater emphasis on mechanistic evidence, based on key characteristics of carcinogens; greater consideration of quality and informativeness in the critical evaluation of epidemiological studies, including their exposure assessment methods; improved harmonization of evaluation criteria for the different evidence streams; and a single-step process of integrating evidence on cancer in humans, cancer in experimental animals, and mechanisms for reaching overall evaluations. In all, the updated Preamble underpins a stronger and more transparent method for the identification of carcinogenic hazards, the essential first step in cancer prevention.

Improving and Expanding Estimates of the Global Burden of Disease Due to Environmental Health Risk Factors

BACKGROUND

The Global Burden of Disease (GBD) study, coordinated by the Institute for Health Metrics and Evaluation (IHME), produces influential, data-driven estimates of the burden of disease and premature death due to major risk factors. Expanded quantification of disease due to environmental health (EH) risk factors, including climate change, will enhance accuracy of GBD estimates, which will contribute to developing cost-effective policies that promote prevention and achieving Sustainable Development Goals.

OBJECTIVES

We review key aspects of the GBD for the EH community and introduce the Global Burden of Disease-Pollution and Health Initiative (GBD-PHI), which aims to work with IHME and the GBD study to improve estimates of disease burden attributable to EH risk factors and to develop an innovative approach to estimating climate-related disease burden-both current and projected.

METHODS

We discuss strategies for improving GBD quantification of specific EH risk factors, including air pollution, lead, and climate change. We highlight key methodological challenges, including new EH risk factors, notably evidence rating and global exposure assessment.

DISCUSSION

A number of issues present challenges to the scope and accuracy of current GBD estimates for EH risk factors. For air pollution, minimal data exist on the exposure-risk relationships associated with high levels of pollution; epidemiological studies in high pollution regions should be a research priority. For lead, the GBD's current methods do not fully account for lead's impact on neurodevelopment; innovative methods to account for subclinical effects are needed. Decisions on inclusion of additional EH risk-outcome pairs need to be guided by findings of systematic reviews, the size of exposed populations, feasibility of global exposure estimates, and predicted trends in exposures and diseases. Neurotoxicants, endocrine-disrupting chemicals, and climate-related factors should be high priorities for incorporation into upcoming iterations of the GBD study. Enhancing the scope and methods will improve the GBD's estimates and better guide prevention policy. https://doi.org/10.1289/EHP5496.

Systematic evidence maps as a novel tool to support evidence-based decision-making in chemicals policy and risk management

BACKGROUND

While systematic review (SR) methods are gaining traction as a method for providing a reliable summary of existing evidence for health risks posed by exposure to chemical substances, it is becoming clear that their value is restricted to a specific range of risk management scenarios - in particular, those which can be addressed with tightly focused questions and can accommodate the time and resource requirements of a systematic evidence synthesis.

METHODS

The concept of a systematic evidence map (SEM) is defined and contrasted to the function and limitations of systematic review (SR) in the context of risk management decision-making. The potential for SEMs to facilitate evidence-based decision-making are explored using a hypothetical example in risk management priority-setting. The potential role of SEMs in reference to broader risk management workflows is characterised.

RESULTS

SEMs are databases of systematically gathered research which characterise broad features of the evidence base. Although not intended to substitute for the evidence synthesis element of systematic reviews, SEMs provide a comprehensive, queryable summary of a large body of policy relevant research. They provide an evidence-based approach to characterising the extent of available evidence and support forward looking predictions or trendspotting in the chemical risk sciences. In particular, SEMs facilitate the identification of related bodies of decision critical chemical risk information which could be further analysed using SR methods, and highlight gaps in the evidence which could be addressed with additional primary studies to reduce uncertainties in decision-making.

CONCLUSIONS

SEMs have strong and growing potential as a high value tool in resource efficient use of existing research in chemical risk management. They can be used as a critical precursor to efficient deployment of high quality SR methods for characterising chemical health risks. Furthermore, SEMs have potential, at a large scale, to support the sort of evidence summarisation and surveillance methods which would greatly increase the resource efficiency, transparency and effectiveness of regulatory initiatives such as EU REACH and US TSCA.

WHO/ILO work-related burden of disease and injury: Protocol for systematic reviews of occupational exposure to solar ultraviolet radiation and of the effect of occupational exposure to solar ultraviolet radiation on melanoma and non-melanoma skin cancer

BACKGROUND

The World Health Organization (WHO) and the International Labour Organization (ILO) are developing a joint methodology for estimating the national and global work-related burden of disease and injury (WHO/ILO joint methodology), with contributions from a large network of experts. In this paper, we present the protocol for two systematic reviews of parameters for estimating the number of deaths and disability-adjusted life years from melanoma and non-melanoma skin cancer (or keratinocyte carcinoma) from occupational exposure to solar ultraviolet radiation, to inform the development of the WHO/ILO joint methodology.

OBJECTIVES

We aim to systematically review studies on occupational exposure to solar ultraviolet radiation (Systematic Review 1) and systematically review and meta-analyse estimates of the effect of occupational exposure to solar ultraviolet radiation on melanoma and non-melanoma skin cancer (Systematic Review 2), applying the Navigation Guide systematic review methodology as an organizing framework and conducting both systematic reviews in tandem and in a harmonized way.

DATA SOURCES

Separately for Systematic Reviews 1 and 2, we will search electronic academic databases for potentially relevant records from published and unpublished studies, including Ovid Medline, PubMed, EMBASE, and Web of Science. We will also search electronic grey literature databases, Internet search engines and organizational websites; hand-search reference list of previous systematic reviews and included study records and consult additional experts.

STUDY ELIGIBILITY AND CRITERIA

We will include working-age (≥15 years) workers in the formal and informal economy in any WHO and/or ILO Member State, but exclude children (<15 years) and unpaid domestic workers. For Systematic Review 1, we will include quantitative studies on the prevalence of relevant levels of occupational exposure to solar ultraviolet radiation (i.e. <0.33 SED/d and ≥0.33 SED/d) and of the total working time spent outdoors, stratified by country, sex, age and industrial sector or occupation, in the years 1960 to 2018. For Systematic Review 2, we will include randomized controlled trials, cohort studies, case-control studies and other non-randomized intervention studies with an estimate of the effect of any occupational exposure to solar ultraviolet radiation (i.e., ≥0.33 SED/d) on the prevalence of, incidence of or mortality due to melanoma and non-melanoma skin cancer, compared with the theoretical minimum risk exposure level (i.e. <0.33 SED/d).

STUDY APPRAISAL AND SYNTHESIS METHODS

At least two review authors will independently screen titles and abstracts against the eligibility criteria at a first stage and full texts of potentially eligible records at a second stage, followed by extraction of data from qualifying studies. At least two review authors will assess the risk of bias and the quality of evidence, using the most suited tools currently available. For Systematic Review 2, if feasible, we will combine relative risks using meta-analysis. We will report results using the guidelines for accurate and transparent health estimates reporting (GATHER) for Systematic Review 1 and the preferred reporting items for systematic reviews and meta-analyses guidelines (PRISMA) for Systematic Review 2.

PROSPERO REGISTRATION NUMBER

CRD42018094817.