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McBride DE, Bhattacharya A, Sucharew H, Brunst KJ, Barnas M, Cox C, Altman L, Hilbert TJ, Burkle J, Westneat S, Martin KV, Parsons PJ, Praamsma ML, Palmer CD, Kannan K, Smith DR, Wright R, Amarasiriwardena C, Dietrich KN, Cecil KM, Haynes EN. Child and Adolescent Manganese Biomarkers and Adolescent Postural Balance in Marietta CARES Cohort Participants. ENVIRONMENTAL HEALTH PERSPECTIVES 2024; 132:57010. [PMID: 38780454 PMCID: PMC11114102 DOI: 10.1289/ehp13381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 03/04/2024] [Accepted: 04/26/2024] [Indexed: 05/25/2024]
Abstract
BACKGROUND Manganese (Mn) plays a significant role in both human health and global industries. Epidemiological studies of exposed populations demonstrate a dose-dependent association between Mn and neuromotor effects ranging from subclinical effects to a clinically defined syndrome. However, little is known about the relationship between early life Mn biomarkers and adolescent postural balance. OBJECTIVES This study investigated the associations between childhood and adolescent Mn biomarkers and adolescent postural balance in participants from the longitudinal Marietta Communities Actively Researching Exposures Study (CARES) cohort. METHODS Participants were recruited into CARES when they were 7-9 y old, and reenrolled at 13-18 years of age. At both time points, participants provided samples of blood, hair, and toenails that were analyzed for blood Mn and lead (Pb), serum cotinine, hair Mn, and toenail Mn. In adolescence, participants completed a postural balance assessment. Greater sway indicates postural instability (harmful effect), whereas lesser sway indicates postural stability (beneficial effect). Multivariable linear regression models were conducted to investigate the associations between childhood and adolescent Mn biomarkers and adolescent postural balance adjusted for age, sex, height-weight ratio, parent/caregiver intelligence quotient, socioeconomic status, blood Pb, and serum cotinine. RESULTS CARES participants who completed the adolescent postural balance assessment (n = 123 ) were 98% White and 54% female and had a mean age of 16 y (range: 13-18 y). In both childhood and adolescence, higher Mn biomarker concentrations were significantly associated with greater adolescent sway measures. Supplemental analyses revealed sex-specific associations; higher childhood Mn biomarker concentrations were significantly associated with greater sway in females compared with males. DISCUSSION This study found childhood and adolescent Mn biomarkers were associated with subclinical neuromotor effects in adolescence. This study demonstrates postural balance as a sensitive measure to assess the association between Mn biomarkers and neuromotor function. https://doi.org/10.1289/EHP13381.
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Affiliation(s)
- Danielle E. McBride
- Department of Epidemiology and Environmental Health, College of Public Health, University of Kentucky, Lexington, Kentucky, USA
| | - Amit Bhattacharya
- Department of Environmental and Public Health Sciences, College of Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - Heidi Sucharew
- Department of Emergency Medicine, College of Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - Kelly J. Brunst
- Department of Environmental and Public Health Sciences, College of Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - Mary Barnas
- Department of Psychology, Marietta College, Marietta, Ohio, USA
| | - Cyndy Cox
- Department of Environmental and Public Health Sciences, College of Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - Lorenna Altman
- Department of Environmental and Public Health Sciences, College of Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - Timothy J. Hilbert
- Department of Environmental and Public Health Sciences, College of Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - Jeff Burkle
- Department of Environmental and Public Health Sciences, College of Medicine, University of Cincinnati, Cincinnati, Ohio, USA
- Division of Asthma Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, USA
| | - Susan Westneat
- Department of Epidemiology and Environmental Health, College of Public Health, University of Kentucky, Lexington, Kentucky, USA
| | - Kaitlin Vollet Martin
- Department of Epidemiology and Environmental Health, College of Public Health, University of Kentucky, Lexington, Kentucky, USA
| | - Patrick J. Parsons
- Division of Environmental Health Sciences, Wadsworth Center, New York State Department of Health, Albany, New York, USA
- Department of Environmental Health Sciences, School of Public Health, University at Albany, State University of New York, Rensselaer, New York, USA
| | - Meredith L. Praamsma
- Division of Environmental Health Sciences, Wadsworth Center, New York State Department of Health, Albany, New York, USA
- Department of Environmental Health Sciences, School of Public Health, University at Albany, State University of New York, Rensselaer, New York, USA
| | - Christopher D. Palmer
- Division of Environmental Health Sciences, Wadsworth Center, New York State Department of Health, Albany, New York, USA
- Department of Environmental Health Sciences, School of Public Health, University at Albany, State University of New York, Rensselaer, New York, USA
| | - Kurunthachalam Kannan
- Division of Environmental Health Sciences, Wadsworth Center, New York State Department of Health, Albany, New York, USA
- Department of Environmental Health Sciences, School of Public Health, University at Albany, State University of New York, Rensselaer, New York, USA
| | - Donald R. Smith
- Department of Microbiology and Environmental Toxicology, University of California, Santa Cruz, California, USA
| | - Robert Wright
- Environmental Medicine and Public Health, Mount Sinai School of Medicine, New York, New York, USA
| | - Chitra Amarasiriwardena
- Environmental Medicine and Public Health, Mount Sinai School of Medicine, New York, New York, USA
| | - Kim N. Dietrich
- Department of Environmental and Public Health Sciences, College of Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - Kim M. Cecil
- Department of Environmental and Public Health Sciences, College of Medicine, University of Cincinnati, Cincinnati, Ohio, USA
- Department of Radiology, Cincinnati Children’s Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Erin N. Haynes
- Department of Epidemiology and Environmental Health, College of Public Health, University of Kentucky, Lexington, Kentucky, USA
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2
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Mittal L, Perry CS, Blanchette AD, Proctor DM. Probabilistic risk assessment of residential exposure to electric arc furnace steel slag using Bayesian model of relative bioavailability and PBPK modeling of manganese. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2024. [PMID: 38622492 DOI: 10.1111/risa.14309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 01/17/2024] [Accepted: 02/14/2024] [Indexed: 04/17/2024]
Abstract
Electric arc furnace (EAF) slag is a coproduct of steel production used primarily for construction purposes. Some applications of EAF slag result in residential exposures by incidental ingestion and inhalation of airborne dust. To evaluate potential health risks, an EAF slag characterization program was conducted to measure concentrations of metals and leaching potential (including oral bioaccessibility) in 38 EAF slag samples. Arsenic, hexavalent chromium, iron, vanadium, and manganese (Mn) were identified as constituents of interest (COIs). Using a probabilistic risk assessment (PRA) approach, estimated distributions of dose for COIs were assessed, and increased cancer risks and noncancer hazard quotients (HQs) at the 50th and 95th percentiles were calculated. For the residents near slag-covered roads, cancer risk and noncancer HQs were <1E - 6 and 1, respectively. For residential driveway or landscape exposure, at the 95th percentile, cancer risks were 1E - 6 and 7E - 07 based on oral exposure to arsenic and hexavalent chromium, respectively. HQs ranged from 0.07 to 2 with the upper bound due to ingestion of Mn among children. To expand the analysis, a previously published physiologically based pharmacokinetic (PBPK) model was used to estimate Mn levels in the globus pallidus for both exposure scenarios and further evaluate the potential for Mn neurotoxicity. The PBPK model estimated slightly increased Mn in the globus pallidus at the 95th percentile of exposure, but concentrations did not exceed no-observed-adverse-effect levels for neurological effects. Overall, the assessment found that the application of EAF slag in residential areas is unlikely to pose a health hazard or increased cancer risk.
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Dorman DC. The Role of Oxidative Stress in Manganese Neurotoxicity: A Literature Review Focused on Contributions Made by Professor Michael Aschner. Biomolecules 2023; 13:1176. [PMID: 37627240 PMCID: PMC10452838 DOI: 10.3390/biom13081176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 07/21/2023] [Accepted: 07/26/2023] [Indexed: 08/27/2023] Open
Abstract
This literature review focuses on the evidence implicating oxidative stress in the pathogenesis of manganese neurotoxicity. This review is not intended to be a systematic review of the relevant toxicologic literature. Instead, in keeping with the spirit of this special journal issue, this review highlights contributions made by Professor Michael Aschner's laboratory in this field of study. Over the past two decades, his laboratory has made significant contributions to our scientific understanding of cellular responses that occur both in vitro and in vivo following manganese exposure. These studies have identified molecular targets of manganese toxicity and their respective roles in mitochondrial dysfunction, inflammation, and cytotoxicity. Other studies have focused on the critical role astrocytes play in manganese neurotoxicity. Recent studies from his laboratory have used C. elegans to discover new facets of manganese-induced neurotoxicity. Collectively, his body of work has dramatically advanced the field and presents broader implications beyond metal toxicology.
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Affiliation(s)
- David C Dorman
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, 1052 William Moore Dr, Raleigh, NC 27606, USA
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4
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Brown JS, Diamond GL. Derivation of first-order dissolution rates to estimate particle clearance and burden in the human respiratory tract. Part Fibre Toxicol 2023; 20:17. [PMID: 37106371 PMCID: PMC10134572 DOI: 10.1186/s12989-023-00523-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Accepted: 04/04/2023] [Indexed: 04/29/2023] Open
Abstract
Inhalation is a portal-of-entry for aerosols via the respiratory tract where particulate burden accumulates depending on sites of particle deposition, normal clearance mechanisms, and particle solubility. The time available for dissolution of particles is determined by the balance between the rate of particle clearance from a region and their solubility in respiratory solvents. Dissolution is a function of particle surface area divided by particle volume or mass (i.e., dissolution is inversely proportional to the physical diameter of particles). As a conservative approach, investigators commonly assume the complete and instantaneous dissolution of metals from particles depositing in the alveolar region of the respiratory tract. We derived first-order dissolution rate constants to facilitate biokinetic modeling of particle clearance, dissolution, and absorption into the blood. We then modeled pulmonary burden and total dissolution of particles over time as a function of particle size, density, and solubility. We show that assuming poorly soluble particle forms will enter the blood as quickly as highly soluble forms causes an overestimation of concentrations of the compound of interest in blood and other extrapulmonary tissues while also underestimating its pulmonary burden. We conclude that, in addition to modeling dose rates for particle deposition into the lung, physiologically based pharmacokinetic modeling of pulmonary and extrapulmonary tissues concentrations of moderately and poorly soluble materials can be improved by including estimates of lung burden and particle dissolution over time.
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Affiliation(s)
- James S Brown
- U.S. Environmental Protection Agency, Office of Research and Development, 109 TW Alexander Drive, Mail Code B243-01, Research Triangle Park, NC, 27711, USA.
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5
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Deepika D, Kumar V. The Role of "Physiologically Based Pharmacokinetic Model (PBPK)" New Approach Methodology (NAM) in Pharmaceuticals and Environmental Chemical Risk Assessment. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:3473. [PMID: 36834167 PMCID: PMC9966583 DOI: 10.3390/ijerph20043473] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 02/10/2023] [Accepted: 02/14/2023] [Indexed: 06/18/2023]
Abstract
Physiologically Based Pharmacokinetic (PBPK) models are mechanistic tools generally employed in the pharmaceutical industry and environmental health risk assessment. These models are recognized by regulatory authorities for predicting organ concentration-time profiles, pharmacokinetics and daily intake dose of xenobiotics. The extension of PBPK models to capture sensitive populations such as pediatric, geriatric, pregnant females, fetus, etc., and diseased populations such as those with renal impairment, liver cirrhosis, etc., is a must. However, the current modelling practices and existing models are not mature enough to confidently predict the risk in these populations. A multidisciplinary collaboration between clinicians, experimental and modeler scientist is vital to improve the physiology and calculation of biochemical parameters for integrating knowledge and refining existing PBPK models. Specific PBPK covering compartments such as cerebrospinal fluid and the hippocampus are required to gain mechanistic understanding about xenobiotic disposition in these sub-parts. The PBPK model assists in building quantitative adverse outcome pathways (qAOPs) for several endpoints such as developmental neurotoxicity (DNT), hepatotoxicity and cardiotoxicity. Machine learning algorithms can predict physicochemical parameters required to develop in silico models where experimental data are unavailable. Integrating machine learning with PBPK carries the potential to revolutionize the field of drug discovery and development and environmental risk. Overall, this review tried to summarize the recent developments in the in-silico models, building of qAOPs and use of machine learning for improving existing models, along with a regulatory perspective. This review can act as a guide for toxicologists who wish to build their careers in kinetic modeling.
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Affiliation(s)
- Deepika Deepika
- Environmental Engineering Laboratory, Departament d’Enginyeria Quimica, Universitat Rovira i Virgili, Av. Països Catalans 26, 43007 Tarragona, Catalonia, Spain
- Pere Virgili Health Research Institute (IISPV), Hospital Universitari Sant Joan de Reus, Universitat Rovira i Virgili, 43204 Reus, Catalonia, Spain
| | - Vikas Kumar
- Environmental Engineering Laboratory, Departament d’Enginyeria Quimica, Universitat Rovira i Virgili, Av. Països Catalans 26, 43007 Tarragona, Catalonia, Spain
- Pere Virgili Health Research Institute (IISPV), Hospital Universitari Sant Joan de Reus, Universitat Rovira i Virgili, 43204 Reus, Catalonia, Spain
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6
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Karyakina NA, Shilnikova N, Farhat N, Ramoju S, Cline B, Momoli F, Mattison D, Jensen N, Terrell R, Krewski D. Biomarkers for occupational manganese exposure. Crit Rev Toxicol 2022; 52:636-663. [PMID: 36705643 DOI: 10.1080/10408444.2022.2128718] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Long-term inhalation exposure to manganese (Mn) metal or its inorganic compounds can result in manganism or subclinical neurofunctional deficits. Studies have described affected workers in Mn dioxide mining, Mn-containing ore crushing and milling facilities, manufacturing of dry-cell batteries, Mn steel and alloy production plants, and in welders. The objective of this study was to critically review existing evidence on the reliability of potential biomarkers of Mn exposure, specifically the relationship between inhalation exposure to Mn particulates in different occupational settings and Mn concentrations in blood and other biological fluids and tissues, with a particular focus on whole blood as a potentially useful medium for measuring internal tissue dose. We also examined available evidence on the relationship between Mn levels in blood and adverse clinical and subclinical neurotoxic outcomes. Three bibliographic databases were searched for relevant studies and identified references were screened by two independent reviewers. Of the 6338 unique references identified, 76 articles were retained for data abstraction. Findings indicate that the relationships between Mn in blood and both external Mn exposure indices and neurofunctional impairments are limited and inconsistent. Different sources of exposure to Mn compounds, heterogeneity in the methodological approaches, and inadequate reporting of essential information limited direct comparison of the reported findings. Among the Mn-exposure biomarkers considered in this review - including biomarkers in blood, plasma, serum, erythrocytes, urine, bone, toenails, fingernails, hair, saliva - biomarkers in whole blood may provide to be most useful in Mn biomonitoring and risk assessment.
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Affiliation(s)
- Nataliya A Karyakina
- Risk Sciences International, Ottawa, Canada.,McLaughlin Centre for Population Health Risk Assessment, University of Ottawa, Ottawa, Canada
| | - Natalia Shilnikova
- Risk Sciences International, Ottawa, Canada.,McLaughlin Centre for Population Health Risk Assessment, University of Ottawa, Ottawa, Canada
| | - Nawal Farhat
- Risk Sciences International, Ottawa, Canada.,School of Mathematics and Statistics, Carleton University, Ottawa, Canada.,School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada
| | | | | | - Franco Momoli
- Risk Sciences International, Ottawa, Canada.,School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada
| | - Donald Mattison
- Risk Sciences International, Ottawa, Canada.,School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada.,Arnold School of Public Health, University of South Carolina, Columbia, SC, USA
| | - N Jensen
- Risk Sciences International, Ottawa, Canada.,School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada
| | - R Terrell
- Risk Sciences International, Ottawa, Canada.,School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada
| | - Daniel Krewski
- Risk Sciences International, Ottawa, Canada.,McLaughlin Centre for Population Health Risk Assessment, University of Ottawa, Ottawa, Canada.,School of Mathematics and Statistics, Carleton University, Ottawa, Canada.,School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada
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7
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Shilnikova N, Karyakina N, Farhat N, Ramoju S, Cline B, Momoli F, Mattison D, Jensen N, Terrell R, Krewski D. Biomarkers of environmental manganese exposure. Crit Rev Toxicol 2022; 52:325-343. [PMID: 35894753 DOI: 10.1080/10408444.2022.2095979] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
We conducted a critical review on biomarkers of environmental manganese (Mn) exposure to answer the following questions: 1) are there reliable biomarkers of internal Mn exposure (Mn in biological matrices) associated with external metrics of Mn exposure (Mn in environmental media)? and 2) are there accurate reference values (RVs) for Mn in biological matrices? Three bibliographic databases were searched for relevant references and identified references were screened by two independent reviewers. Of the 6342 unique references identified, 86 articles were retained for data abstraction. Our analysis of currently available evidence suggests that Mn levels in blood and urine are not useful biomarkers of Mn exposure in non-occupational settings. The strength of the association between Mn in environmental media and saliva was variable. Findings regarding the utility of hair Mn as a biomarker of environmental Mn exposure are inconsistent. Measurements of Mn in teeth are technically challenging and findings on Mn in tooth components are scarce. In non-occupationally exposed individuals, bone Mn measurements using in vivo neutron activation analysis (IVNAA) are associated with large uncertainties. Findings suggest that Mn in nails may reflect Mn in environmental media and discriminate between groups of individuals exposed to different environmental Mn levels, although more research is needed. Currently, there is no strong evidence for any biological matrix as a valid biomarker of Mn exposure in non-occupational settings. Because of methodological limitations in studies aimed at derivation of RVs for Mn in biological materials, accurate RVs are scarce.
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Affiliation(s)
- Natalia Shilnikova
- Risk Sciences International, Ottawa, Canada.,McLaughlin Centre for Population Health Risk Assessment, University of Ottawa, Ottawa, Canada
| | - Nataliya Karyakina
- Risk Sciences International, Ottawa, Canada.,McLaughlin Centre for Population Health Risk Assessment, University of Ottawa, Ottawa, Canada
| | - Nawal Farhat
- Risk Sciences International, Ottawa, Canada.,McLaughlin Centre for Population Health Risk Assessment, University of Ottawa, Ottawa, Canada.,School of Mathematics and Statistics, Carleton University, Ottawa, Canada
| | | | | | - Franco Momoli
- Risk Sciences International, Ottawa, Canada.,School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada
| | - Donald Mattison
- Risk Sciences International, Ottawa, Canada.,School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada.,Arnold School of Public Health, University of South Carolina, Columbia, SC, USA
| | - Natalie Jensen
- Risk Sciences International, Ottawa, Canada.,School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada
| | - Rowan Terrell
- Risk Sciences International, Ottawa, Canada.,School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada
| | - Daniel Krewski
- Risk Sciences International, Ottawa, Canada.,McLaughlin Centre for Population Health Risk Assessment, University of Ottawa, Ottawa, Canada.,School of Mathematics and Statistics, Carleton University, Ottawa, Canada.,School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada
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8
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Crofton KM, Bassan A, Behl M, Chushak YG, Fritsche E, Gearhart JM, Marty MS, Mumtaz M, Pavan M, Ruiz P, Sachana M, Selvam R, Shafer TJ, Stavitskaya L, Szabo DT, Szabo ST, Tice RR, Wilson D, Woolley D, Myatt GJ. Current status and future directions for a neurotoxicity hazard assessment framework that integrates in silico approaches. COMPUTATIONAL TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2022; 22:100223. [PMID: 35844258 PMCID: PMC9281386 DOI: 10.1016/j.comtox.2022.100223] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
Neurotoxicology is the study of adverse effects on the structure or function of the developing or mature adult nervous system following exposure to chemical, biological, or physical agents. The development of more informative alternative methods to assess developmental (DNT) and adult (NT) neurotoxicity induced by xenobiotics is critically needed. The use of such alternative methods including in silico approaches that predict DNT or NT from chemical structure (e.g., statistical-based and expert rule-based systems) is ideally based on a comprehensive understanding of the relevant biological mechanisms. This paper discusses known mechanisms alongside the current state of the art in DNT/NT testing. In silico approaches available today that support the assessment of neurotoxicity based on knowledge of chemical structure are reviewed, and a conceptual framework for the integration of in silico methods with experimental information is presented. Establishing this framework is essential for the development of protocols, namely standardized approaches, to ensure that assessments of NT and DNT based on chemical structures are generated in a transparent, consistent, and defendable manner.
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Affiliation(s)
| | - Arianna Bassan
- Innovatune srl, Via Giulio Zanon 130/D, 35129 Padova,
Italy
| | - Mamta Behl
- Division of the National Toxicology Program, National
Institutes of Environmental Health Sciences, Durham, NC 27709, USA
| | - Yaroslav G. Chushak
- Henry M Jackson Foundation for the Advancement of Military
Medicine, Wright-Patterson AFB, OH 45433, USA
| | - Ellen Fritsche
- IUF – Leibniz Research Institute for Environmental
Medicine & Medical Faculty Heinrich-Heine-University, Düsseldorf,
Germany
| | - Jeffery M. Gearhart
- Henry M Jackson Foundation for the Advancement of Military
Medicine, Wright-Patterson AFB, OH 45433, USA
| | | | - Moiz Mumtaz
- Agency for Toxic Substances and Disease Registry, US
Department of Health and Human Services, Atlanta, GA, USA
| | - Manuela Pavan
- Innovatune srl, Via Giulio Zanon 130/D, 35129 Padova,
Italy
| | - Patricia Ruiz
- Agency for Toxic Substances and Disease Registry, US
Department of Health and Human Services, Atlanta, GA, USA
| | - Magdalini Sachana
- Environment Health and Safety Division, Environment
Directorate, Organisation for Economic Co-Operation and Development (OECD), 75775
Paris Cedex 16, France
| | - Rajamani Selvam
- Office of Clinical Pharmacology, Office of Translational
Sciences, Center for Drug Evaluation and Research (CDER), U.S. Food and Drug
Administration (FDA), Silver Spring, MD 20993, USA
| | - Timothy J. Shafer
- Biomolecular and Computational Toxicology Division, Center
for Computational Toxicology and Exposure, US EPA, Research Triangle Park, NC,
USA
| | - Lidiya Stavitskaya
- Office of Clinical Pharmacology, Office of Translational
Sciences, Center for Drug Evaluation and Research (CDER), U.S. Food and Drug
Administration (FDA), Silver Spring, MD 20993, USA
| | | | | | | | - Dan Wilson
- The Dow Chemical Company, Midland, MI 48667, USA
| | | | - Glenn J. Myatt
- Instem, Columbus, OH 43215, USA
- Corresponding author.
(G.J. Myatt)
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9
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Jensen N, Terrell R, Ramoju S, Shilnikova N, Farhat N, Karyakina N, Cline BH, Momoli F, Mattison D, Krewski D. Magnetic resonance imaging T1 indices of the brain as biomarkers of inhaled manganese exposure. Crit Rev Toxicol 2022; 52:358-370. [PMID: 36412542 DOI: 10.1080/10408444.2022.2128719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Excessive exposure to manganese (Mn) is linked to its accumulation in the brain and adverse neurological effects. Paramagnetic properties of Mn allow the use of magnetic resonance imaging (MRI) techniques to identify it in biological tissues. A critical review was conducted to evaluate whether MRI techniques could be used as a diagnostic tool to detect brain Mn accumulation as a quantitative biomarker of inhaled exposure. A comprehensive search was conducted in MEDLINE, EMBASE, and PubMed to identify potentially relevant studies published prior to 9 May 2022. Two reviewers independently screened identified references using a two-stage process. Of the 6452 unique references identified, 36 articles were retained for data abstraction. Eligible studies used T1-weighted MRI techniques and reported direct or indirect T1 measures to characterize Mn accumulation in the brain. Findings demonstrate that, in subjects exposed to high levels of Mn, deposition in the brain is widespread, accumulating both within and outside the basal ganglia. Available evidence indicates that T1 MRI techniques can be used to distinguish Mn-exposed individuals from unexposed. Additionally, T1 MRI may be useful for semi-quantitative evaluation of inhaled Mn exposure, particularly when interpreted along with other exposure indices. T1 MRI measures appear to have a nonlinear relationship to Mn exposure duration, with R1 signal only increasing after critical thresholds. The strength of the association varied depending on the regions of interest imaged and the method of exposure measurement. Overall, available evidence suggests potential for future clinical and risk assessment applications of MRI as a diagnostic tool.
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Affiliation(s)
- N Jensen
- Risk Sciences International, Ottawa, Canada.,School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada
| | - R Terrell
- Risk Sciences International, Ottawa, Canada.,School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada
| | - S Ramoju
- Risk Sciences International, Ottawa, Canada
| | - N Shilnikova
- Risk Sciences International, Ottawa, Canada.,McLaughlin Centre for Population Health Risk Assessment, University of Ottawa, Ottawa, Canada
| | - N Farhat
- Risk Sciences International, Ottawa, Canada.,School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada.,School of Mathematics and Statistics, Carleton University, Ottawa, Canada
| | - N Karyakina
- Risk Sciences International, Ottawa, Canada.,McLaughlin Centre for Population Health Risk Assessment, University of Ottawa, Ottawa, Canada
| | - B H Cline
- International Manganese Institute, Paris, France
| | - F Momoli
- Risk Sciences International, Ottawa, Canada.,School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada
| | - D Mattison
- Risk Sciences International, Ottawa, Canada.,School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada.,Arnold School of Public Health, University of South Carolina, Columbia, SC, USA
| | - D Krewski
- Risk Sciences International, Ottawa, Canada.,School of Epidemiology and Public Health, University of Ottawa, Ottawa, Canada.,McLaughlin Centre for Population Health Risk Assessment, University of Ottawa, Ottawa, Canada.,School of Mathematics and Statistics, Carleton University, Ottawa, Canada
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10
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McCarrick S, Karlsson HL, Carlander U. Modelled lung deposition and retention of welding fume particles in occupational scenarios: a comparison to doses used in vitro. Arch Toxicol 2022; 96:969-985. [PMID: 35188583 PMCID: PMC8921161 DOI: 10.1007/s00204-022-03247-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 02/02/2022] [Indexed: 11/25/2022]
Abstract
Translating particle dose from in vitro systems to relevant human exposure remains a major challenge for the use of in vitro studies in assessing occupational hazard and risk of particle exposure. This study aimed to model the lung deposition and retention of welding fume particles following occupational scenarios and subsequently compare the lung doses to those used in vitro. We reviewed published welding fume concentrations and size distributions to identify input values simulating real-life exposure scenarios in the multiple path particle dosimetry (MPPD) model. The majority of the particles were reported to be below 0.1 μm and mass concentrations ranged between 0.05 and 45 mg/m3. Following 6-h exposure to 5 mg/m3 with a count median diameter of 50 nm, the tracheobronchial lung dose (0.89 µg/cm2) was found to exceed the in vitro cytotoxic cell dose (0.125 µg/cm2) previously assessed by us in human bronchial epithelial cells (HBEC-3kt). However, the tracheobronchial retention decreased rapidly when no exposure occurred, in contrast to the alveolar retention which builds-up over time and exceeded the in vitro cytotoxic cell dose after 1.5 working week. After 1 year, the tracheobronchial and alveolar retention was estimated to be 1.15 and 2.85 µg/cm2, respectively. Exposure to low-end aerosol concentrations resulted in alveolar retention comparable to cytotoxic in vitro dose in HBEC-3kt after 15-20 years of welding. This study demonstrates the potential of combining real-life exposure data with particle deposition modelling to improve the understanding of in vitro concentrations in the context of human occupational exposure.
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Affiliation(s)
- Sarah McCarrick
- Institute of Environmental Medicine, Karolinska Institutet, 171 77, Stockholm, Sweden.
| | - Hanna L Karlsson
- Institute of Environmental Medicine, Karolinska Institutet, 171 77, Stockholm, Sweden
| | - Ulrika Carlander
- Institute of Environmental Medicine, Karolinska Institutet, 171 77, Stockholm, Sweden
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11
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Yao W, Gallagher DL, Dietrich AM. Risks to children from inhalation of aerosolized aqueous manganese emitted from ultrasonic humidifiers can be greater than for corresponding ingestion. WATER RESEARCH 2021; 207:117760. [PMID: 34800908 DOI: 10.1016/j.watres.2021.117760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 09/22/2021] [Accepted: 10/10/2021] [Indexed: 06/13/2023]
Abstract
UNLABELLED The essential trace element manganese (Mn) can cause neurotoxicity with inhalation acknowledged as a more severe health and cognition threat than ingestion. METHODS Over a range of aqueous Mn concentrations present in tap water, this research characterizes exposures and risks for adults and 0.25, 1, 2.5, and 6 yr old children who ingest the water and inhale respirable particles produced by a room-sized ultrasonic humidifier filled with the same water. Aqueous Mn concentrations evaluated included 50 µg/L USEPA esthetic guideline, 80 µg/L WHO infant guideline, and 120 µg/L Canadian regulatory level. Airborne-particle-bound Mn concentrations were generated for water filling an ultrasonic humidifier under four realistic room conditions (33 m3 small or 72 m3 large) with varying ventilation rates from 0.2/h -1.5/h. Average daily doses (ADD) and reference intake doses were calculated for ingestion and 8-h inhalation of humidified air. Hazard quotients (HQ) compared the intake doses and reference doses. Multi-path particle dosimetry (MPPD) model quantified the particle deposition and deposited dose in children's and adults' respiratory tracts. RESULTS At only 11 µg/L Mn, the resulting humidified air Mn exceeds USEPA's reference concentration of 0.05 µg/m3 Mn in small room with low, energy-efficient ventilation. Inhalation ADD are 2 magnitudes lower than ingestion ADD for identical water Mn concentrations and daily exposure frequency. Even so, ingestion HQs are approximately 0.2 but inhalation risk is significant (HQ>1) for children and adults when breathing Mn-humidified air under most small room conditions at 50, 80 or 120 µg/L Mn. MPPD model indicates inhaled Mn deposits in head and pulmonary regions, with greater Mn dose deposits in children than adults. CONCLUSION Inhalation of Mn-particles produced from ultrasonic humidifiers can pose greater risks than ingestion at the same water concentration, especially for children. Aqueous Mn concentration and room size influence risks. Limiting manganese exposures and setting regulations requires consideration of both ingestion and inhalation of water.
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Affiliation(s)
- Wenchuo Yao
- Department of Civil and Environmental Engineering, Virginia Tech, 413 Durham Hall, Blacksburg, Virginia 24061, United States
| | - Daniel L Gallagher
- Department of Civil and Environmental Engineering, Virginia Tech, 413 Durham Hall, Blacksburg, Virginia 24061, United States
| | - Andrea M Dietrich
- Department of Civil and Environmental Engineering, Virginia Tech, 413 Durham Hall, Blacksburg, Virginia 24061, United States.
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12
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Bailey LA, Boomhower SR. Potential implications of new information concerning manganese Ohio community health effects studies. Regul Toxicol Pharmacol 2021; 127:105069. [PMID: 34718075 DOI: 10.1016/j.yrtph.2021.105069] [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: 06/22/2021] [Revised: 10/12/2021] [Accepted: 10/21/2021] [Indexed: 11/24/2022]
Abstract
Several epidemiology studies have been conducted in Ohio communities where industrial facilities with manganese emissions are located. New information not addressed in the published papers for this research has been disclosed by U.S. federal agencies pursuant to the Freedom of Information Act. This paper describes the newly available information, presents statistical analyses of the new summary data, and explores how this information potentially impacts the conclusions of the published research. Based on a statistical analysis of the newly available data, we found very few, and no consistent, statistical differences for various illnesses, self-reported symptoms, and neuropsychological/neuromotor test results between one community with a manganese emission source and a control town that were part of the initial research. Further, we determined that the distribution of total suspended particulate manganese air concentrations did not correlate with the distribution of the more biologically relevant respirable manganese concentrations when data from two communities with potential manganese emissions were combined. These results are important, particularly in determining whether the studies should influence regulatory reference values related to manganese. We recommend that the full health effects data set associated with the published research be made available and re-evaluated to address the issues identified in this paper.
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Affiliation(s)
- Lisa A Bailey
- Gradient, One Beacon Street, Boston, MA, 02108, USA.
| | - Steven R Boomhower
- Gradient, One Beacon Street, Boston, MA, 02108, USA; Harvard Division of Continuing Education, Harvard University, Cambridge, MA, 02138, USA
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13
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Zhuang H, Zhong Y, Yang L. Adsorption equilibrium and kinetics studies of divalent manganese from phosphoric acid solution by using cationic exchange resin. Chin J Chem Eng 2020. [DOI: 10.1016/j.cjche.2020.07.029] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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14
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Deepika D, Sharma RP, Schuhmacher M, Kumar V. An integrative translational framework for chemical induced neurotoxicity – a systematic review. Crit Rev Toxicol 2020; 50:424-438. [DOI: 10.1080/10408444.2020.1763253] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Deepika Deepika
- Environmental Engineering Laboratory, Departament d’ Enginyeria Quimica, Universitat Rovira i Virgili, Tarragona, Catalonia, Spain
| | - Raju Prasad Sharma
- Environmental Engineering Laboratory, Departament d’ Enginyeria Quimica, Universitat Rovira i Virgili, Tarragona, Catalonia, Spain
| | - Marta Schuhmacher
- Environmental Engineering Laboratory, Departament d’ Enginyeria Quimica, Universitat Rovira i Virgili, Tarragona, Catalonia, Spain
| | - Vikas Kumar
- Environmental Engineering Laboratory, Departament d’ Enginyeria Quimica, Universitat Rovira i Virgili, Tarragona, Catalonia, Spain
- IISPV, Hospital Universitari Sant Joan de Reus, Universitat Rovira I Virgili, Reus, Spain
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15
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Ijomone OM, Aluko OM, Okoh COA, Martins AC, Aschner M. Role for calcium signaling in manganese neurotoxicity. J Trace Elem Med Biol 2019; 56:146-155. [PMID: 31470248 DOI: 10.1016/j.jtemb.2019.08.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Revised: 08/15/2019] [Accepted: 08/16/2019] [Indexed: 12/31/2022]
Abstract
BACKGROUND Calcium is an essential macronutrient that is involved in many cellular processes. Homeostatic control of intracellular levels of calcium ions [Ca2+] is vital to maintaining cellular structure and function. Several signaling molecules are involved in regulating Ca2+ levels in cells and perturbation of calcium signaling processes is implicated in several neurodegenerative and neurologic conditions. Manganese [Mn] is a metal which is essential for basic physiological functions. However, overexposure to Mn from environmental contamination and workplace hazards is a global concern. Mn overexposure leads to its accumulation in several human organs particularly the brain. Mn accumulation in the brain results in a manganism, a Parkinsonian-like syndrome. Additionally, Mn is a risk factor for several neurodegenerative diseases including Parkinson's disease and Alzheimer's disease. Mn neurotoxicity also affects several neurotransmitter systems including dopaminergic, cholinergic and GABAergic. The mechanisms of Mn neurotoxicity are still being elucidated. AIM The review will highlight a potential role for calcium signaling molecules in the mechanisms of Mn neurotoxicity. CONCLUSION Ca2+ regulation influences the neurodegenerative process and there is possible role for perturbed calcium signaling in Mn neurotoxicity. Mechanisms implicated in Mn-induced neurodegeneration include oxidative stress, generation of free radicals, and apoptosis. These are influenced by mitochondrial integrity which can be dependent on intracellular Ca2+ homeostasis. Nevertheless, further elucidation of the direct effects of calcium signaling dysfunction and calcium-binding proteins activities in Mn neurotoxicity is required.
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Affiliation(s)
- Omamuyovwi M Ijomone
- The Neuro- Lab, Department of Human Anatomy, Federal University of Technology Akure, Ondo, Nigeria.
| | - Oritoke M Aluko
- Department of Physiology, Federal University of Technology Akure, Ondo, Nigeria
| | - Comfort O A Okoh
- The Neuro- Lab, Department of Human Anatomy, Federal University of Technology Akure, Ondo, Nigeria
| | - Airton Cunha Martins
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, United States.
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16
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Edmondson DA, Ma RE, Yeh CL, Ward E, Snyder S, Azizi E, Zauber SE, Wells EM, Dydak U. Reversibility of neuroimaging markers influenced by lifetime occupational manganese exposure. Toxicol Sci 2019; 172:181-190. [PMID: 31388678 PMCID: PMC6813746 DOI: 10.1093/toxsci/kfz174] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 05/24/2019] [Accepted: 07/08/2019] [Indexed: 11/13/2022] Open
Abstract
Manganese (Mn) is a neurotoxicant that many workers are exposed to daily. There is limited knowledge about how changes in exposure levels impact measures in magnetic resonance imaging (MRI). We hypothesized that changes in Mn exposure would be reflected by changes in the MRI relaxation rate R1 and thalamic γ-aminobutyric acid (GABAThal). As part of a prospective cohort study, 17 welders were recruited and imaged on two separate occasions approximately two years apart. MRI relaxometry was used to assess changes of Mn accumulation in the brain. Additionally, GABA was measured using magnetic resonance spectroscopy (MRS) in the thalamic and striatal regions of the brain. Air Mn exposure ([Mn]Air) and cumulative exposure indexes of Mn (Mn-CEI) for the past three months (Mn-CEI3M), past year (Mn-CEI12M), and lifetime (Mn-CEILife) were calculated using personal air sampling and a comprehensive work history, while toenails were collected for analysis of internal Mn body burden. Finally, welders' motor function was examined using the Unified Parkinson's Disease Rating Scale (UPDRS). Median exposure decreased for all exposure measures between the first and second scan. ΔGABAThal was significantly correlated with ΔMn-CEI3M (ρ = 0.66, adjusted p = 0.02), ΔMn-CEI12M (ρ = 0.70, adjusted p = 0.006) , and Δ[Mn]Air (ρ = 0.77, adjusted p = 0.002). ΔGABAThal significantly decreased linearly with ΔMn-CEI3M (quantile regression, β = 15.22, p = 0.02) as well as Δ[Mn]Air (β = 1.27, p = 0.04). Finally, Mn-CEILife interacted with Δ[Mn]Air in the substantia nigra where higher Mn-CEILife lessened the ΔR1 per Δ[Mn]Air (F-test, p = 0.005). While R1 and GABA changed with Mn exposure, UPDRS was unaffected. In conclusion, our study shows that effects from changes in Mn exposure are reflected in thalamic GABA levels and brain Mn levels, as measured by R1, in most brain regions.
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Affiliation(s)
- David A Edmondson
- School of Health Sciences, Purdue University, West Lafayette, IN.,Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN
| | - Ruoyun E Ma
- School of Health Sciences, Purdue University, West Lafayette, IN.,Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN.,Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN
| | - Chien-Lin Yeh
- School of Health Sciences, Purdue University, West Lafayette, IN.,Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN
| | - Eric Ward
- School of Health Sciences, Purdue University, West Lafayette, IN
| | - Sandy Snyder
- School of Health Sciences, Purdue University, West Lafayette, IN
| | - Elham Azizi
- Department of Neurology, Ochsner Medical Center, Kenner, LA
| | - S Elizabeth Zauber
- Department of Neurology, Indiana University School of Medicine, Indianapolis, IN
| | - Ellen M Wells
- School of Health Sciences, Purdue University, West Lafayette, IN.,Public Health Graduate Program, Purdue University, West Lafayette, IN
| | - Ulrike Dydak
- School of Health Sciences, Purdue University, West Lafayette, IN.,Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN
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17
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Leonhard MJ, Chang ET, Loccisano AE, Garry MR. A systematic literature review of epidemiologic studies of developmental manganese exposure and neurodevelopmental outcomes. Toxicology 2019; 420:46-65. [PMID: 30928475 DOI: 10.1016/j.tox.2019.03.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 03/10/2019] [Accepted: 03/19/2019] [Indexed: 12/27/2022]
Abstract
BACKGROUND Neurotoxic effects of high-level occupational exposure to manganese (Mn) are well established; however, whether lower-level environmental exposure to Mn in early life causes neurodevelopmental toxicity in children is unclear. METHODS A systematic literature review was conducted to identify and evaluate epidemiologic studies of specific Mn biomarkers assessed during gestation, childhood, or adolescence in association with neurodevelopmental outcomes, focusing on quantitative exposure-response estimates with specific endpoints that were assessed in multiple independent study populations. Study quality was evaluated using the revised RTI item bank and the Cochrane Risk of Bias tool, and the overall weight of epidemiologic evidence for causality was evaluated according to the Bradford Hill considerations. RESULTS Twenty-two epidemiologic studies were identified that estimated associations between early-life Mn biomarkers and neurodevelopmental outcomes. Seven of these studies provided adjusted estimates for the association with child intelligence assessed using versions of the Wechsler Intelligence Scales for Children; no other specific neurodevelopmental endpoints were assessed in more than three independent study populations each. Among the studies of child intelligence, five studies in four independent populations measured blood Mn, three studies measured hair Mn, and one measured dentin Mn. Overall, cross-sectional associations between Mn biomarkers and measures of child intelligence were mostly statistically nonsignificant but in a negative direction; however, the lone prospective cohort study found mostly null results, with some positive (favorable) associations between dentin Mn and child intelligence. Studies were methodologically limited by their cross-sectional design and potential for confounding and selection bias, as well as unaddressed questions on exposure assessment validity and biological plausibility. CONCLUSIONS The statistical associations reported in the few studies of specific Mn biomarkers and specific neurodevelopmental endpoints do not establish causal effects based on the Bradford Hill considerations. Additional prospective cohort studies of Mn biomarkers and validated neurodevelopmental outcomes, and a better understanding of the etiologic relevance of Mn biomarkers, are needed to shed light on whether environmental exposure to Mn causes adverse neurodevelopmental effects in children.
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Affiliation(s)
- Megan J Leonhard
- Exponent, Inc., Center for Health Sciences, 15375 SE 30th Place, Suite 250, Bellevue, WA 98007, United States.
| | - Ellen T Chang
- Exponent, Inc., Center for Health Sciences, 149 Commonwealth Drive, Menlo Park, CA 94025, United States.
| | - Anne E Loccisano
- Exponent, Inc., Center for Health Sciences, 1800 Diagonal Road, Suite 500, Alexandria, VA 22314, United States.
| | - Michael R Garry
- Exponent, Inc., Center for Health Sciences, 15375 SE 30th Place, Suite 250, Bellevue, WA 98007, United States.
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18
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Physiologically-based pharmacokinetic modeling suggests similar bioavailability of Mn from diet and drinking water. Toxicol Appl Pharmacol 2018; 359:70-81. [DOI: 10.1016/j.taap.2018.09.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 09/16/2018] [Accepted: 09/17/2018] [Indexed: 12/29/2022]
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19
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Myhre O, Låg M, Villanger GD, Oftedal B, Øvrevik J, Holme JA, Aase H, Paulsen RE, Bal-Price A, Dirven H. Early life exposure to air pollution particulate matter (PM) as risk factor for attention deficit/hyperactivity disorder (ADHD): Need for novel strategies for mechanisms and causalities. Toxicol Appl Pharmacol 2018; 354:196-214. [PMID: 29550511 DOI: 10.1016/j.taap.2018.03.015] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 02/14/2018] [Accepted: 03/12/2018] [Indexed: 12/11/2022]
Abstract
Epidemiological studies have demonstrated that air pollution particulate matter (PM) and adsorbed toxicants (organic compounds and trace metals) may affect child development already in utero. Recent studies have also indicated that PM may be a risk factor for neurodevelopmental disorders (NDDs). A pattern of increasing prevalence of attention deficit/hyperactivity disorder (ADHD) has been suggested to partly be linked to environmental pollutants exposure, including PM. Epidemiological studies suggest associations between pre- or postnatal exposure to air pollution components and ADHD symptoms. However, many studies are cross-sectional without possibility to reveal causality. Cohort studies are often small with poor exposure characterization, and confounded by traffic noise and socioeconomic factors, possibly overestimating the study associations. Furthermore, the mechanistic knowledge how exposure to PM during early brain development may contribute to increased risk of ADHD symptoms or cognitive deficits is limited. The closure of this knowledge gap requires the combined use of well-designed longitudinal cohort studies, supported by mechanistic in vitro studies. As ADHD has profound consequences for the children affected and their families, the identification of preventable risk factors such as air pollution exposure should be of high priority.
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Affiliation(s)
- Oddvar Myhre
- Department of Toxicology and Risk Assessment, Norwegian Institute of Public Health, Oslo, Norway.
| | - Marit Låg
- Department of Air pollution and Noise, Norwegian Institute of Public Health, Oslo, Norway
| | - Gro D Villanger
- Department of Child Health and Development, Norwegian Institute of Public Health, Oslo, Norway
| | - Bente Oftedal
- Department of Air pollution and Noise, Norwegian Institute of Public Health, Oslo, Norway
| | - Johan Øvrevik
- Department of Air pollution and Noise, Norwegian Institute of Public Health, Oslo, Norway
| | - Jørn A Holme
- Department of Air pollution and Noise, Norwegian Institute of Public Health, Oslo, Norway
| | - Heidi Aase
- Department of Child Health and Development, Norwegian Institute of Public Health, Oslo, Norway
| | - Ragnhild E Paulsen
- Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Norway
| | - Anna Bal-Price
- European Commission, Joint Research Centre, Ispra, Italy
| | - Hubert Dirven
- Department of Toxicology and Risk Assessment, Norwegian Institute of Public Health, Oslo, Norway
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20
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Clippinger AJ, Allen D, Jarabek AM, Corvaro M, Gaça M, Gehen S, Hotchkiss JA, Patlewicz G, Melbourne J, Hinderliter P, Yoon M, Huh D, Lowit A, Buckley B, Bartels M, BéruBé K, Wilson DM, Indans I, Vinken M. Alternative approaches for acute inhalation toxicity testing to address global regulatory and non-regulatory data requirements: An international workshop report. Toxicol In Vitro 2017; 48:53-70. [PMID: 29277654 DOI: 10.1016/j.tiv.2017.12.011] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 12/11/2017] [Accepted: 12/14/2017] [Indexed: 12/15/2022]
Abstract
Inhalation toxicity testing, which provides the basis for hazard labeling and risk management of chemicals with potential exposure to the respiratory tract, has traditionally been conducted using animals. Significant research efforts have been directed at the development of mechanistically based, non-animal testing approaches that hold promise to provide human-relevant data and an enhanced understanding of toxicity mechanisms. A September 2016 workshop, "Alternative Approaches for Acute Inhalation Toxicity Testing to Address Global Regulatory and Non-Regulatory Data Requirements", explored current testing requirements and ongoing efforts to achieve global regulatory acceptance for non-animal testing approaches. The importance of using integrated approaches that combine existing data with in vitro and/or computational approaches to generate new data was discussed. Approaches were also proposed to develop a strategy for identifying and overcoming obstacles to replacing animal tests. Attendees noted the importance of dosimetry considerations and of understanding mechanisms of acute toxicity, which could be facilitated by the development of adverse outcome pathways. Recommendations were made to (1) develop a database of existing acute inhalation toxicity data; (2) prepare a state-of-the-science review of dosimetry determinants, mechanisms of toxicity, and existing approaches to assess acute inhalation toxicity; (3) identify and optimize in silico models; and (4) develop a decision tree/testing strategy, considering physicochemical properties and dosimetry, and conduct proof-of-concept testing. Working groups have been established to implement these recommendations.
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Affiliation(s)
| | - David Allen
- Integrated Laboratory Systems, contractor supporting the NTP Interagency Center for the Evaluation of Alternative Toxicological Methods, Research Triangle Park, NC, United States
| | - Annie M Jarabek
- U.S. Environmental Protection Agency, Office of Research and Development, National Center for Environmental Assessment, Research Triangle Park, NC, United States
| | | | | | - Sean Gehen
- Dow AgroSciences, Indianapolis, IN, United States
| | | | - Grace Patlewicz
- U.S. Environmental Protection Agency, Office of Research and Development, National Center for Computational Toxicology, Research Triangle Park, NC, United States
| | | | | | - Miyoung Yoon
- Scitovation LLC, Research Triangle Park, NC, United States
| | - Dongeun Huh
- University of Pennsylvania, Philadelphia, PA, United States
| | - Anna Lowit
- U.S. Environmental Protection Agency, Office of Chemical Safety and Pollution Prevention, Office of Pesticide Programs, Washington, DC, United States
| | - Barbara Buckley
- U.S. Environmental Protection Agency, Office of Research and Development, National Center for Environmental Assessment, Research Triangle Park, NC, United States
| | | | - Kelly BéruBé
- Cardiff University, School of Biosciences, Cardiff, Wales, UK
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21
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Park RM, Berg SL. Manganese and neurobehavioral impairment. A preliminary risk assessment. Neurotoxicology 2017; 64:159-165. [PMID: 28803851 DOI: 10.1016/j.neuro.2017.08.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 07/26/2017] [Accepted: 08/07/2017] [Indexed: 01/23/2023]
Abstract
Similar patterns of cognitive and motor deficits have been widely reported from manganese exposures in welding, metallurgical and chemical industry workers. A risk assessment was performed based on studies reported in the literature, extending some earlier work, and deriving new estimates of exposure response and excess risk. Many investigations of manganese neurological effects in humans have insufficient information to derive an exposure response; however, findings from a chemical manufacturer, two smelter and two welder populations permitted application of the benchmark dose procedure for continuous end-points. Small particles and aggregates of condensation fume (condensing vaporized metal, <0.1μm in diameter) appear to have a higher potency per unit mass than larger particles from dusts (>1.0μm). Consideration was given to long-term effects of continuous low exposures that instead of producing increasing toxicity attain a steady-state condition. Impairment was defined as excursions beyond the 5th percentile in a normal population and the concentrations of manganese predicted to result in 1% excess prevalence of impairment over different time periods were calculated. Over five years, exposures resulting in 1% excess prevalence of impairment (for purposes of discussion) were in the vicinity of 10μg/m3 for manganese fume and 25μg/m3 for larger particle dusts. These levels are below current recommendations for occupational limits on manganese exposure in the United States.
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Affiliation(s)
- Robert M Park
- Risk Evaluation Branch, Education and Information Division, National Institute for Occupational Safety and Health, Cincinnati, OH, USA.
| | - Shannon L Berg
- Document Development Branch, Education and Information Division, National Institute for Occupational Safety and Health, Cincinnati, OH, USA
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22
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Smith D, Woodall GM, Jarabek AM, Boyes WK. Manganese testing under a clean air act test rule and the application of resultant data in risk assessments. Neurotoxicology 2017; 64:177-184. [PMID: 28676206 DOI: 10.1016/j.neuro.2017.06.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 06/27/2017] [Indexed: 01/19/2023]
Abstract
In the 1990's, the proposed use of methylcyclopentadienyl manganese tricarbonyl (MMT) as an octane-enhancing gasoline fuel additive led to concerns for potential public health consequences from exposure to manganese (Mn) combustion products in automotive exhaust. After a series of regulatory/legal actions and negotiations, the U.S. Environmental Protection Agency (EPA) issued under Clean Air Act (CAA) section 211(b) an Alternative Tier 2 Test Rule that required development of scientific information intended to help resolve uncertainties in exposure or health risk estimates associated with MMT use. Among the uncertainties identified were: the chemical forms of Mn emitted in automotive exhaust; the relative toxicity of different Mn species; the potential for exposure among sensitive subpopulations including females, the young and elderly; differences in sensitivity between test species and humans; differences between inhalation and oral exposures; and the influence of dose rate and exposure duration on tissue accumulation of Mn. It was anticipated that development of specific sets of pharmacokinetic (PK) information and models regarding Mn could help resolve many of the identified uncertainties and serve as the best foundation for available data integration. The results of the test program included development of several unique Mn datasets, and a series of increasingly sophisticated Mn physiologically-based pharmacokinetic (PBPK) models. These data and models have helped address each of the uncertainties originally identified in the Test Rule. The output from these PBPK models were used by the Agency for Toxic Substances and Disease Registry (ATSDR) in 2012 to inform the selection of uncertainty factors for deriving the manganese Minimum Risk Level (MRL) for chronic exposure durations. The EPA used the MRL in the Agency's 2015 evaluation of potential residual risks of airborne manganese released from ferroalloys production plants. This resultant set of scientific data and models likely would not exist without the CAA section 211(b) test rule regulatory procedure.
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Affiliation(s)
- Darcie Smith
- Office of Air Quality Planning and Standards, Office of Air and Radiation, U.S. Environmental Protection Agency, Research Triangle Park, NC, United States
| | - George M Woodall
- National Center for Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, United States
| | - Annie M Jarabek
- National Center for Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, United States
| | - William K Boyes
- Toxicity Assessment Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC, United States.
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23
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Abstract
Although an essential nutrient, manganese (Mn) can be toxic at high doses. There is, however, uncertainty regarding the effects of chronic low-level Mn-exposure. This review provides an overview of Mn-related brain and functional changes based on studies of a cohort of asymptomatic welders who had lower Mn-exposure than in most previous work. In welders with low-level Mn-exposure, we found: 1) Mn may accumulate in the brain in a non-linear fashion: MRI R1 (1/T1) signals significantly increased only after a critical level of exposure was reached (e.g., ≥300 welding hours in the past 90days prior to MRI). Moreover, R1 may be a more sensitive marker to capture short-term dynamic changes in Mn accumulation than the pallidal index [T1-weighted intensity ratio of the globus pallidus vs. frontal white matter], a traditional marker for Mn accumulation; 2) Chronic Mn-exposure may lead to microstructural changes as indicated by lower diffusion tensor fractional anisotropy values in the basal ganglia (BG), especially when welding years exceeded more than 30 years; 3) Mn-related subtle motor dysfunctions can be captured sensitively by synergy metrics (indices for movement stability), whereas traditional fine motor tasks failed to detect any significant differences; and 4) Iron (Fe) also may play a role in welding-related neurotoxicity, especially at low-level Mn-exposure, evidenced by higher R2* values (an estimate for brain Fe accumulation) in the BG. Moreover, higher R2* values were associated with lower phonemic fluency performance. These findings may guide future studies and the development of occupation- and public health-related polices involving Mn-exposure.
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