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Najjar A, Kühnl J, Lange D, Géniès C, Jacques C, Fabian E, Zifle A, Hewitt NJ, Schepky A. Next-generation risk assessment read-across case study: application of a 10-step framework to derive a safe concentration of daidzein in a body lotion. Front Pharmacol 2024; 15:1421601. [PMID: 38962304 PMCID: PMC11220827 DOI: 10.3389/fphar.2024.1421601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Accepted: 05/29/2024] [Indexed: 07/05/2024] Open
Abstract
Introduction: We performed an exposure-based Next Generation Risk Assessment case read-across study using New Approach Methodologies (NAMs) to determine the highest safe concentration of daidzein in a body lotion, based on its similarities with its structural analogue, genistein. Two assumptions were: (1) daidzein is a new chemical and its dietary intake omitted; (2) only in vitro data were used for daidzein, while in vitro and legacy in vivo data for genistein were considered. Methods: The 10-step tiered approach evaluating systemic toxicity included toxicokinetics NAMs: PBPK models and in vitro biokinetics measurements in cells used for toxicogenomics and toxicodynamic NAMs: pharmacology profiling (i.e., interaction with molecular targets), toxicogenomics and EATS assays (endocrine disruption endpoints). Whole body rat and human PBPK models were used to convert external doses of genistein to plasma concentrations and in vitro Points of Departure (PoD) to external doses. The PBPK human dermal module was refined using in vitro human skin metabolism and penetration data. Results: The most relevant endpoint for daidzein was from the ERα assay (Lowest Observed Effective Concentration was 100 ± 0.0 nM), which was converted to an in vitro PoD of 33 nM. After application of a safety factor of 3.3 for intra-individual variability, the safe concentration of daidzein was estimated to be 10 nM. This was extrapolated to an external dose of 0.5 μg/cm2 for a body lotion and face cream, equating to a concentration of 0.1%. Discussion: When in vitro PoD of 33 nM for daidzein was converted to an external oral dose in rats, the value correlated with the in vivo NOAEL. This increased confidence that the rat oral PBPK model provided accurate estimates of internal and external exposure and that the in vitro PoD was relevant in the safety assessment of both chemicals. When plasma concentrations estimated from applications of 0.1% and 0.02% daidzein were used to calculate bioactivity exposure ratios, values were >1, indicating a good margin between exposure and concentrations causing adverse effects. In conclusion, this case study highlights the use of NAMs in a 10-step tiered workflow to conclude that the highest safe concentration of daidzein in a body lotion is 0.1%.
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Affiliation(s)
| | | | | | - Camille Géniès
- Pierre Fabre Dermo-Cosmétique and Personal CareToulouse, Toulouse, France
| | - Carine Jacques
- Pierre Fabre Dermo-Cosmétique and Personal CareToulouse, Toulouse, France
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2
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Fu K, Hua J, Zhang Y, Du M, Han J, Li N, Wang Q, Yang L, Li R, Zhou B. Integrated Studies on Male Reproductive Toxicity of Bis(2-ethylhexyl)-tetrabromophthalate: in Silico, in Vitro, ex Vivo, and in Vivo. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:194-206. [PMID: 38113192 DOI: 10.1021/acs.est.3c07129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
Bis(2-ethylhexyl)tetrabromophthalate (TBPH) has been widely detected in the environment and organisms; thus, its toxic effects on male reproduction were systematically studied. First, we found that TBPH can stably bind to the androgen receptor (AR) based on in silico molecular docking results and observed an antagonistic activity, but not agonistic activity, on the AR signaling pathway using a constructed AR-GRIP1 yeast assay. Subsequently, we validated the adverse effects on male germ cells by observing inhibited androgen production and proliferation in Leydig cells upon in vitro exposure and affected general motility and motive tracks of zebrafish sperm upon ex vivo exposure. Finally, the in vivo reproductive toxicity was demonstrated in male zebrafish by reduced mating behavior in F0 generation when paired with unexposed females and abnormal development of their offspring. In addition, reduced sperm motility and impaired germ cells in male zebrafish were also observed, which may be related to the disturbed homeostasis of sex hormones. Notably, the specifically suppressed AR in the brain provides further evidence for the antagonistic effects as above-mentioned. These results confirmed that TBPH affected male reproduction through a classical nuclear receptor-mediated pathway, which would be helpful for assessing the ecological and health risks of TBPH.
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Affiliation(s)
- Kaiyu Fu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jianghuan Hua
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- School of Basic Medical Sciences, Hubei University of Chinese Medicine, Wuhan 430065, China
| | - Yindan Zhang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mingpu Du
- Ecology and Environment Monitoring and Scientific Research Center, Ecology and Environment Administration of Yangtze River Basin, Ministry of Ecology and Environment, Wuhan 430010, China
| | - Jian Han
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Na Li
- Key Laboratory of Drinking Water Science and Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Qiangwei Wang
- Institute of Pesticide and Environmental Toxicology, Zhejiang University, Hangzhou 310058, China
| | - Lihua Yang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Ruiwen Li
- Ecology and Environment Monitoring and Scientific Research Center, Ecology and Environment Administration of Yangtze River Basin, Ministry of Ecology and Environment, Wuhan 430010, China
| | - Bingsheng Zhou
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
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Magurany KA, English JC, Cox KD. Application of the threshold of toxicological concern (TTC) in the evaluation of drinking water contact chemicals. Toxicol Mech Methods 2023:1-17. [PMID: 38031359 DOI: 10.1080/15376516.2023.2279041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 10/30/2023] [Indexed: 12/01/2023]
Abstract
The Threshold of Toxicological Concern (TTC) is an approach for assessing the safety of chemicals with low levels of exposure for which limited toxicology data are available. The original TTC criteria were derived for oral exposures from a distributional analysis of a dataset of 613 chemicals that identified 5th percentile no observed effect level (NOEL) values grouped within three tiers of compounds having specific structural functional groups and/or toxic potencies known as Cramer I, II and III classifications. Subsequent assessments of the TTC approach have established current thresholds to be scientifically robust. While the TTC has gained acknowledgment and acceptance by many regulatory agencies and organizations, use of the TTC approach in evaluating drinking water chemicals has been limited. To apply the TTC concept to drinking water chemicals, an exposure-based approach that incorporates the current weight of evidence for the target chemical is presented. Such an approach provides a comparative point of departure to the 5th percentile TTC NOEL using existing data, while conserving the allocation of toxicological resources for quantitative risk assessment to chemicals with greater exposure or toxicity. This approach will be considered for incorporation into NSF/ANSI/CAN 600, a health effects standard used in the safety evaluation of chemicals present in drinking water from drinking water contact additives and materials certified to NSF/ANSI/CAN 60 and 61, respectively.
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Affiliation(s)
| | | | - Kevin D Cox
- Water Toxics Unit, Michigan Department of Environment, Great Lakes and Energy (EGLE), Lansing, MI, USA
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Mitchell CA, Burden N, Bonnell M, Hecker M, Hutchinson TH, Jagla M, LaLone CA, Lagadic L, Lynn SG, Shore B, Song Y, Vliet SM, Wheeler JR, Embry MR. New Approach Methodologies for the Endocrine Activity Toolbox: Environmental Assessment for Fish and Amphibians. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2023; 42:757-777. [PMID: 36789969 PMCID: PMC10258674 DOI: 10.1002/etc.5584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 11/07/2022] [Accepted: 02/06/2023] [Indexed: 06/14/2023]
Abstract
Multiple in vivo test guidelines focusing on the estrogen, androgen, thyroid, and steroidogenesis pathways have been developed and validated for mammals, amphibians, or fish. However, these tests are resource-intensive and often use a large number of laboratory animals. Developing alternatives for in vivo tests is consistent with the replacement, reduction, and refinement principles for animal welfare considerations, which are supported by increasing mandates to move toward an "animal-free" testing paradigm worldwide. New approach methodologies (NAMs) hold great promise to identify molecular, cellular, and tissue changes that can be used to predict effects reliably and more efficiently at the individual level (and potentially on populations) while reducing the number of animals used in (eco)toxicological testing for endocrine disruption. In a collaborative effort, experts from government, academia, and industry met in 2020 to discuss the current challenges of testing for endocrine activity assessment for fish and amphibians. Continuing this cross-sector initiative, our review focuses on the current state of the science regarding the use of NAMs to identify chemical-induced endocrine effects. The present study highlights the challenges of using NAMs for safety assessment and what work is needed to reduce their uncertainties and increase their acceptance in regulatory processes. We have reviewed the current NAMs available for endocrine activity assessment including in silico, in vitro, and eleutheroembryo models. New approach methodologies can be integrated as part of a weight-of-evidence approach for hazard or risk assessment using the adverse outcome pathway framework. The development and utilization of NAMs not only allows for replacement, reduction, and refinement of animal testing but can also provide robust and fit-for-purpose methods to identify chemicals acting via endocrine mechanisms. Environ Toxicol Chem 2023;42:757-777. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
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Affiliation(s)
| | - Natalie Burden
- National Centre for the 3Rs (NC3Rs), London, United Kingdom
| | - Mark Bonnell
- Environment and Climate Change Canada, Ottawa, Canada
| | - Markus Hecker
- Toxicology Centre and School of the Environment & Sustainability, University of Saskatchewan, Saskatoon, Canada
| | | | | | - Carlie A. LaLone
- Office of Research and Development, Great Lakes Toxicology & Ecology Division, US Environmental Protection Agency, Duluth, Minnesota
| | - Laurent Lagadic
- Research and Development, Crop Science, Environmental Safety, Bayer, Monheim am Rhein, Germany
| | - Scott G. Lynn
- Office of Pesticide Programs, US Environmental Protection Agency, Washington, DC
| | - Bryon Shore
- Environment and Climate Change Canada, Ottawa, Canada
| | - You Song
- Norwegian Institute for Water Research, Oslo, Norway
| | - Sara M. Vliet
- Office of Research and Development, Scientific Computing and Data Curation Division, US Environmental Protection Agency, Duluth, Minnesota
| | | | - Michelle R. Embry
- The Health and Environmental Sciences Institute, Washington, DC, USA
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5
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Caballero Alfonso AY, Chayawan C, Gadaleta D, Roncaglioni A, Benfenati E. A KNIME Workflow to Assist the Analogue Identification for Read-Across, Applied to Aromatase Activity. Molecules 2023; 28:molecules28041832. [PMID: 36838826 PMCID: PMC9961311 DOI: 10.3390/molecules28041832] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 02/07/2023] [Accepted: 02/10/2023] [Indexed: 02/18/2023] Open
Abstract
The reduction and replacement of in vivo tests have become crucial in terms of resources and animal benefits. The read-across approach reduces the number of substances to be tested, exploiting existing experimental data to predict the properties of untested substances. Currently, several tools have been developed to perform read-across, but other approaches, such as computational workflows, can offer a more flexible and less prescriptive approach. In this paper, we are introducing a workflow to support analogue identification for read-across. The implementation of the workflow was performed using a database of azole chemicals with in vitro toxicity data for human aromatase enzymes. The workflow identified analogues based on three similarities: structural similarity (StrS), metabolic similarity (MtS), and mechanistic similarity (McS). Our results showed how multiple similarity metrics can be combined within a read-across assessment. The use of the similarity based on metabolism and toxicological mechanism improved the predictions in particular for sensitivity. Beyond the results predicting a large population of substances, practical examples illustrate the advantages of the proposed approach.
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Affiliation(s)
- Ana Yisel Caballero Alfonso
- Laboratory of Environmental Chemistry and Toxicology, Department of Environmental Health Sciences, Istituto di Ricerche Farmacologiche “Mario Negri”—IRCCS, Via Mario Negri, 2, 20156 Milano, Italy
- Jozef Stefan International Postgraduate School, Jamova cesta 39, 1000 Ljubljana, Slovenia
- Correspondence: (A.Y.C.A.); (E.B.)
| | - Chayawan Chayawan
- Laboratory of Environmental Chemistry and Toxicology, Department of Environmental Health Sciences, Istituto di Ricerche Farmacologiche “Mario Negri”—IRCCS, Via Mario Negri, 2, 20156 Milano, Italy
| | - Domenico Gadaleta
- Laboratory of Environmental Chemistry and Toxicology, Department of Environmental Health Sciences, Istituto di Ricerche Farmacologiche “Mario Negri”—IRCCS, Via Mario Negri, 2, 20156 Milano, Italy
| | - Alessandra Roncaglioni
- Laboratory of Environmental Chemistry and Toxicology, Department of Environmental Health Sciences, Istituto di Ricerche Farmacologiche “Mario Negri”—IRCCS, Via Mario Negri, 2, 20156 Milano, Italy
| | - Emilio Benfenati
- Laboratory of Environmental Chemistry and Toxicology, Department of Environmental Health Sciences, Istituto di Ricerche Farmacologiche “Mario Negri”—IRCCS, Via Mario Negri, 2, 20156 Milano, Italy
- Correspondence: (A.Y.C.A.); (E.B.)
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6
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Eliso MC, Bergami E, Bonciani L, Riccio R, Belli G, Belli M, Corsi I, Spagnuolo A. Application of transcriptome profiling to inquire into the mechanism of nanoplastics toxicity during Ciona robusta embryogenesis. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 318:120892. [PMID: 36529345 DOI: 10.1016/j.envpol.2022.120892] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 11/30/2022] [Accepted: 12/15/2022] [Indexed: 06/17/2023]
Abstract
The growing concern on nanoplastics (<1 μm) impact on marine life has stimulated a significant amount of studies aiming to address ecotoxicity and disclose their mechanisms of action. Here, we applied an integrative approach to develop an Adverse Outcome Pathway (AOP) upon acute exposure to amino-modified polystyrene nanoparticles (PS-NH2 NPs, 50 nm), as proxy for nanoplastics, during the embryogenesis of the chordate Ciona robusta. Genes related to glutathione metabolism, immune defense, nervous system, transport by aquaporins and energy metabolism were affected by either concentration tested of 10 or 15 μg mL-1 of PS-NH2. Transcriptomic data and in vivo experiments were assembled into two putative AOPs, identifying as key events the adhesion of PS-NH2 as (molecular) initiating event, followed by oxidative stress, changes in transcription of specific genes, morphological defects, increase in reactive oxygen species level, impaired swimming behavior. As final adverse outcomes, altered larval development, reduced metamorphosis and inhibition of hatching were identified. Our study attempts to define AOPs for PS-NH2 without excluding that chemicals leaching from them might also have a potential role in the observed outcome. Overall data provide new insights into the mechanism of action of PS-NH2 NPs during chordate embryogenesis and offer further keys for a better knowledge of nanoplastics impact on early stages of marine life.
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Affiliation(s)
- Maria Concetta Eliso
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, 80121, Naples, Italy.
| | - Elisa Bergami
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 213/D, 41125, Modena (MO), Italy
| | - Lisa Bonciani
- BioChemie LAB, Via di Limite, 27G, 50013, Campi Bisenzio, FI, Italy
| | - Roberto Riccio
- BioChemie LAB, Via di Limite, 27G, 50013, Campi Bisenzio, FI, Italy
| | - Giulia Belli
- BioChemie LAB, Via di Limite, 27G, 50013, Campi Bisenzio, FI, Italy
| | - Mattia Belli
- BioChemie LAB, Via di Limite, 27G, 50013, Campi Bisenzio, FI, Italy
| | - Ilaria Corsi
- Department of Physical, Earth and Environmental Sciences, University of Siena, 53100, Siena, Italy
| | - Antonietta Spagnuolo
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, 80121, Naples, Italy
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7
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Krewski D, Saunders-Hastings P, Baan RA, Barton-Maclaren TS, Browne P, Chiu WA, Gwinn M, Hartung T, Kraft AD, Lam J, Lewis RJ, Sanaa M, Morgan RL, Paoli G, Rhomberg L, Rooney A, Sand S, Schünemann HJ, Straif K, Thayer KA, Tsaioun K. Development of an Evidence-Based Risk Assessment Framework. ALTEX 2022; 39:667-693. [PMID: 36098377 PMCID: PMC10080579 DOI: 10.14573/altex.2004041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 06/29/2021] [Indexed: 11/23/2022]
Abstract
Assessment of potential human health risks associated with environmental and other agents requires careful evaluation of all available and relevant evidence for the agent of interest, including both data-rich and data-poor agents. With the advent of new approach methodologies in toxicological risk assessment, guidance on integrating evidence from mul-tiple evidence streams is needed to ensure that all available data is given due consideration in both qualitative and quantitative risk assessment. The present report summarizes the discussions among academic, government, and private sector participants from North America and Europe in an international workshop convened to explore the development of an evidence-based risk assessment framework, taking into account all available evidence in an appropriate manner in order to arrive at the best possible characterization of potential human health risks and associated uncertainty. Although consensus among workshop participants was not a specific goal, there was general agreement on the key consider-ations involved in evidence-based risk assessment incorporating 21st century science into human health risk assessment. These considerations have been embodied into an overarching prototype framework for evidence integration that will be explored in more depth in a follow-up meeting.
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Affiliation(s)
- Daniel Krewski
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada
- McLaughlin Centre for Population Health Risk Assessment, University of Ottawa, Ottawa, Canada
- Risk Sciences International, Ottawa, Canada
| | | | - Robert A. Baan
- The IARC Monographs Programme, International Agency for Research on Cancer, Lyon, France (retired)
| | | | - Patience Browne
- Organization for Economic Cooperation and Development, Paris, France
| | - Weihsueh A. Chiu
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, Texas, USA
| | - Maureen Gwinn
- Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, USA
| | - Thomas Hartung
- Chair for Evidence-based Toxicology and Center for Alternatives to Animal Testing (CAAT), Johns Hopkins University, Baltimore, USA
- CAAT-Europe, University of Konstanz, Konstanz, Germany
| | - Andrew D. Kraft
- Center for Public Health and Environmental Assessment, Chemical & Pollutant Assessment Division, US EPA, DC, USA
| | - Juleen Lam
- Department of Public Health at California State University, East Bay, USA
| | - R. Jeffrey Lewis
- ExxonMobil Biomedical Sciences, Annandale, New Jersey, USA (retired)
| | - Moez Sanaa
- Agence Nationale Sécurité Sanitaire Alimentaire Nationale, Paris, France
| | | | - Greg Paoli
- Risk Sciences International, Ottawa, Canada
| | | | - Andrew Rooney
- Integrative Health Assessments Branch, National Toxicology Program, US National Institute of Environmental Health Sciences, Research Triangle Park, USA
| | - Salomon Sand
- Department of Risk and Benefit Assessment, Swedish Food Agency, Uppsala, Sweden
| | | | - Kurt Straif
- The IARC Monographs Programme, International Agency for Research on Cancer, Lyon, France (retired)
| | - Kristina A Thayer
- Center for Public Health and Environmental Assessment, Chemical & Pollutant Assessment Division, US EPA, NC, USA
| | - Katya Tsaioun
- Boston College, Chestnut Hill, MA, USA ISGlobal, Barcelona, Spain
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Bhuller Y, Ramsingh D, Beal M, Kulkarni S, Gagne M, Barton-Maclaren TS. Canadian Regulatory Perspective on Next Generation Risk Assessments for Pest Control Products and Industrial Chemicals. FRONTIERS IN TOXICOLOGY 2022; 3:748406. [PMID: 35295100 PMCID: PMC8915837 DOI: 10.3389/ftox.2021.748406] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 10/11/2021] [Indexed: 12/24/2022] Open
Abstract
In 2012, the Council of Canadian Academies published the expert panel on integrated testing of pesticide’s report titled: Integrating emerging technologies into chemical safety assessment. This report was prepared for the Government of Canada in response to a request from the Minister of Health and on behalf of the Pest Management Regulatory Agency. It examined the scientific status of the use of integrated testing strategies for the regulatory health risk assessment of pesticides while noting the data-rich/poor dichotomy that exists when comparing pesticide formulations to most industrial chemicals. It also noted that the adoption of integrated approaches to testing and assessment (IATA) strategies may refine and streamline testing of chemicals, as well as improve results in the future. Moreover, the experts expected to see an increase in the use of integrated testing strategies over the next decade, resulting in improved evidence-based decision-making. Subsequent to this report, there has been great advancements in IATA strategies, which includes the incorporation of adverse outcome pathways (AOPs) and new approach methodologies (NAMs). This perspective provides the first Canadian regulatory update on how Health Canada is also advancing the incorporation of alternative, non-animal strategies, using a weight of evidence approach, for the evaluation of pest control products and industrial chemicals. It will include specific initiatives and describe how this work is leading to the creation of next generation risk assessments. It also reflects Health Canada’s commitment towards implementing the 3Rs of animal testing: reduce, refine and replace the need for animal studies, whenever possible.
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Affiliation(s)
- Yadvinder Bhuller
- Health Evaluation Directorate, Pest Management Regulatory Agency, Health Canada, Ottawa, ON, Canada
| | - Deborah Ramsingh
- Health Evaluation Directorate, Pest Management Regulatory Agency, Health Canada, Ottawa, ON, Canada
| | - Marc Beal
- Safe Environments Directorate, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, ON, Canada
| | - Sunil Kulkarni
- Safe Environments Directorate, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, ON, Canada
| | - Matthew Gagne
- Safe Environments Directorate, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, ON, Canada
| | - Tara S Barton-Maclaren
- Safe Environments Directorate, Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, ON, Canada
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9
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Barton-Maclaren TS, Wade M, Basu N, Bayen S, Grundy J, Marlatt V, Moore R, Parent L, Parrott J, Grigorova P, Pinsonnault-Cooper J, Langlois VS. Innovation in regulatory approaches for endocrine disrupting chemicals: The journey to risk assessment modernization in Canada. ENVIRONMENTAL RESEARCH 2022; 204:112225. [PMID: 34666016 DOI: 10.1016/j.envres.2021.112225] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 10/12/2021] [Accepted: 10/13/2021] [Indexed: 06/13/2023]
Abstract
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.
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Affiliation(s)
- T S Barton-Maclaren
- Existing Substances Risk Assessment Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Canada.
| | - M Wade
- Environmental Health Centre, Environmental Health, Science and Research Bureau, Health Canada, Ottawa, ON, Canada
| | - N Basu
- Faculty of Agricultural and Environmental Sciences, McGill University, Ste Anne de Bellevue, QC, Canada
| | - S Bayen
- Faculty of Agricultural and Environmental Sciences, McGill University, Ste Anne de Bellevue, QC, Canada
| | - J Grundy
- New Substances Assessment and Control Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Canada
| | - V Marlatt
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - R Moore
- New Substances Assessment and Control Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Canada
| | - L Parent
- Département Science et Technologie, Université TÉLUQ, Montréal, QC, Canada
| | - J Parrott
- Water Science and Technology Directorate, Environment and Climate Change Canada, Burlington, ON, Canada
| | - P Grigorova
- Département Science et Technologie, Université TÉLUQ, Montréal, QC, Canada
| | - J Pinsonnault-Cooper
- New Substances Assessment and Control Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, Canada
| | - V S Langlois
- Institut National de la Recherche Scientifique (INRS), Centre Eau Terre Environnement, Quebec City, QC, Canada
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10
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Burden N, Embry MR, Hutchinson TH, Lynn SG, Maynard SK, Mitchell CA, Pellizzato F, Sewell F, Thorpe KL, Weltje L, Wheeler JR. Investigating endocrine-disrupting properties of chemicals in fish and amphibians: Opportunities to apply the 3Rs. INTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT 2022; 18:442-458. [PMID: 34292658 PMCID: PMC9292818 DOI: 10.1002/ieam.4497] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 05/13/2021] [Accepted: 07/16/2021] [Indexed: 05/04/2023]
Abstract
Many regulations are beginning to explicitly require investigation of a chemical's endocrine-disrupting properties as a part of the safety assessment process for substances already on or about to be placed on the market. Different jurisdictions are applying distinct approaches. However, all share a common theme requiring testing for endocrine activity and adverse effects, typically involving in vitro and in vivo assays on selected endocrine pathways. For ecotoxicological evaluation, in vivo assays can be performed across various animal species, including mammals, amphibians, and fish. Results indicating activity (i.e., that a test substance may interact with the endocrine system) from in vivo screens usually trigger further higher-tier in vivo assays. Higher-tier assays provide data on adverse effects on relevant endpoints over more extensive parts of the organism's life cycle. Both in vivo screening and higher-tier assays are animal- and resource-intensive and can be technically challenging to conduct. Testing large numbers of chemicals will inevitably result in the use of large numbers of animals, contradicting stipulations set out within many regulatory frameworks that animal studies be conducted as a last resort. Improved strategies are urgently required. In February 2020, the UK's National Centre for the 3Rs and the Health and Environmental Sciences Institute hosted a workshop ("Investigating Endocrine Disrupting Properties in Fish and Amphibians: Opportunities to Apply the 3Rs"). Over 50 delegates attended from North America and Europe, across academia, laboratories, and consultancies, regulatory agencies, and industry. Challenges and opportunities in applying refinement and reduction approaches within the current animal test guidelines were discussed, and utilization of replacement and/or new approach methodologies, including in silico, in vitro, and embryo models, was explored. Efforts and activities needed to enable application of 3Rs approaches in practice were also identified. This article provides an overview of the workshop discussions and sets priority areas for follow-up. Integr Environ Assess Manag 2022;18:442-458. © 2021 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).
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Affiliation(s)
| | | | - Thomas H. Hutchinson
- School of Geography, Earth & Environmental SciencesUniversity of PlymouthPlymouthUK
| | - Scott G. Lynn
- US Environmental Protection Agency (EPA)Office of Science Coordination and PolicyWashingtonDCUSA
- Present address:
US Environmental Protection Agency (EPA)Office of Pesticide ProgramsWashingtonDCUSA
| | | | | | | | | | - Karen L. Thorpe
- Centre for Chemical Safety and StewardshipFera Science Ltd.YorkUK
| | - Lennart Weltje
- BASF SE, Agricultural Solutions−EcotoxicologyLimburgerhofGermany
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11
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Felter SP, Bhat VS, Botham PA, Bussard DA, Casey W, Hayes AW, Hilton GM, Magurany KA, Sauer UG, Ohanian EV. Assessing chemical carcinogenicity: hazard identification, classification, and risk assessment. Insight from a Toxicology Forum state-of-the-science workshop. Crit Rev Toxicol 2022; 51:653-694. [DOI: 10.1080/10408444.2021.2003295] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
| | | | | | - David A. Bussard
- U.S. Environmental Protection Agency, Office of the Science Advisor, Policy and Engagement, Washington, DC, USA
| | - Warren Casey
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - A. Wallace Hayes
- University of South Florida College of Public Health, Tampa, FL, USA
| | - Gina M. Hilton
- PETA Science Consortium International e.V., Stuttgart, Germany
| | | | | | - Edward V. Ohanian
- United States Environmental Protection Agency, Office of Water, Washington, DC, USA
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12
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Comparative Study on UV-AOPs for Efficient Continuous Flow Removal of 4-tert-Butylphenol. Processes (Basel) 2021. [DOI: 10.3390/pr10010008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
In the present study, UV-light-driven advanced oxidation processes (AOPs) have been employed for the degradation of 4-tert-Butylphenol (4-t-BP) in water under continuous flow conditions. The effects of varying space time (10, 20, 40, 60 and 120 min) and oxidant dosage (88.3 mg/L, 176.6 mg/L and 264 mg/L) were examined. 4-t-BP degradation efficiency in the UV-induced AOPs followed the order of UV/H2O2 (264.9 mg/L) ≈ UV/Fe2+/H2O2 > UV/Fe3+/H2O2 > UV/H2O2 (176.6 mg/L) > UV/H2O2 (88.3 mg/L) > UV/Fe-TiO2 > UV/TiO2 > UV, while UV/Fe3+/H2O2 was the most efficient process in terms of Total Organic Carbon (TOC) removal (at the space time of 60 min) among those tested. The combination of UV with 88.3 mg/L H2O2 enhanced pollutant removal from 51.29% to 93.34% after 10 min of irradiation. The presence of H2O2 contributed to the highest 4-t-BP and TOC removal values. Interestingly, the increase in space time from 20 to 60 min resulted in surpassing of the activity of the Fe-TiO2 over commercial TiO2, although it had an almost negligible positive impact on the performance of the UV/H2O2 system as well as H2O2 concentration. The results obtained showed that more than 80% of 4-t-BP could be successfully degraded by both heterogeneous and homogeneous AOPs after 60 min.
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Tate T, Wambaugh J, Patlewicz G, Shah I. Repeat-dose toxicity prediction with Generalized Read-Across (GenRA) using targeted transcriptomic data: A proof-of-concept case study. COMPUTATIONAL TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2021; 19:1-12. [PMID: 37309449 PMCID: PMC10259651 DOI: 10.1016/j.comtox.2021.100171] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Read-across is a data gap filling technique utilized to predict the toxicity of a target chemical using data from similar analogues. Recent efforts such as Generalized Read-Across (GenRA) facilitate automated read-across predictions for untested chemicals. GenRA makes predictions of toxicity outcomes based on "neighboring" chemicals characterized by chemical and bioactivity fingerprints. Here we investigated the impact of biological similarities on neighborhood formation and read-across performance in predicting hazard (based on repeat-dose testing outcomes from US EPA ToxRefDB v2.0). We used targeted transcriptomic data on 93 genes for 1060 chemicals in HepaRG™ cells that measure nuclear receptor activation, xenobiotic metabolism, cellular stress, cell cycle progression, and apoptosis. Transcriptomic similarity between chemicals was calculated using binary hit-calls from concentration-response data for each gene. We evaluated GenRA performance in predicting ToxRefDB v2.0 hazard outcomes using the area under the Receiver Operating Characteristic (ROC) curve (AUC) for the baseline approach (chemical fingerprints) versus transcriptomic fingerprints and a combination of both (hybrid). For all endpoints, there were significant but only modest improvements in ROC AUC scores of 0.01 (2.1%) and 0.04 (7.3%) with transcriptomic and hybrid descriptors, respectively. However, for liver-specific toxicity endpoints, ROC AUC scores improved by 10% and 17% for transcriptomic and hybrid descriptors, respectively. Our findings suggest that using hybrid descriptors formed by combining chemical and targeted transcriptomic information can improve in vivo toxicity predictions in the right context.
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Affiliation(s)
| | | | | | - Imran Shah
- Corresponding author at: U.S. Environmental
Protection Agency, 109 TW Alexander Drive (D130A), Research Triangle Park, NC
27711, USA. (I. Shah)
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