1
|
Zuo J, Zhang H, Gang H, Mai Q, Jia Z, Liu H, Xia W, Xu S, Li Y. Associations of intrauterine exposure to manganese with fetal and early-childhood growth: a prospective prenatal cohort study. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:14303-14317. [PMID: 38273082 DOI: 10.1007/s11356-023-31773-1] [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: 08/22/2023] [Accepted: 12/26/2023] [Indexed: 01/27/2024]
Abstract
Prenatal manganese (Mn) exposure may be related to poor birth outcomes; however, there are few relevant epidemiological reports on the effects of intrauterine Mn levels on intrauterine fetal and early childhood growth. From 2013 to 2016, 2082 pairs of mothers and infants were recruited in Wuhan, China, who provided an entire set of urine samples during their first, second, and third trimesters. Fetal head circumference (HC), abdominal circumference (AC), femoral length (FL), and estimated fetal weight (EFW) were obtained by ultrasound at the 16, 24, and 31 weeks of pregnancy. When the children were born, 6 months old, 12 months old, and 24 months old, their weight, height, weight-for-height, and BMI were measured. We used generalized linear models, generalized estimated equations, and restricted cubic spline curves (RCS) to investigate the linear and nonlinear relationships between antenatal Mn levels and fetal and early childhood growth. In all fetuses, Mn exposure during the 1st and 2nd gestation was associated with decreased fetal AC, FL, and EFW at 24 weeks (e.g., for each doubling of urinary Mn concentrations during the 1st and 2nd gestation, the SD score of EFW at 24 weeks decreased by - 4.16% (95% CI, - 6.22%, - 2.10%) and - 3.78% (95% CI, - 5.86%, - 1.70%)). Mn concentrations in the highest tertile group of the 1st and 2nd gestation were related to decreased fetus growth parameters compared to the lowest tertile group. For each doubling of the average Mn concentrations during pregnancy, the z-scores of weight, weight-for-height, and BMI at 12 months decreased, with percentage changes of - 2.93% (95% CI, - 5.08%, - 0.79%), - 3.25% (95% CI, - 5.56%, - 0.94%), and - 3.09% (95% CI, - 5.44%, - 0.73%). In the RCS model, we found a reverse U-shaped association between 1st trimester Mn concentration and fetal FL at 16 weeks and HC at 31 weeks in male fetuses and a non-linear association between mean Mn concentration during pregnancy and girls' weight-for-height and BMI at 6 months. Intrauterine exposure to Mn may be related to restricted growth in the fetus and early childhood, especially in fetuses at 24 weeks of gestation and children at 12 months of age. Also, meaningful curvilinear relationships were found in the sex stratification.
Collapse
Affiliation(s)
- Jingwen Zuo
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Hongling Zhang
- Wuchang University of Technology, Wuhan, 430023, People's Republic of China
| | - Huiqing Gang
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Qi Mai
- Center for Public Health Laboratory Service, Wuhan Centers for Disease Control & Prevention, Institute of Environmental Health, Wuhan, Hubei, 430024, People's Republic of China
| | - Zhenxian Jia
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Hongxiu Liu
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Wei Xia
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Shunqing Xu
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Yuanyuan Li
- Key Laboratory of Environment and Health, Ministry of Education & Ministry of Environmental Protection, and State Key Laboratory of Environmental Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China.
| |
Collapse
|
2
|
Lane JM, Curtin P, Chelonis JJ, Pantic I, Martinez-Medina S, Téllez-Rojo MM, Wright RO. Prenatal manganese biomarkers and operant test battery performance in Mexican children: Effect modification by child sex. ENVIRONMENTAL RESEARCH 2023; 236:116880. [PMID: 37574101 PMCID: PMC10919280 DOI: 10.1016/j.envres.2023.116880] [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: 04/02/2023] [Revised: 08/10/2023] [Accepted: 08/11/2023] [Indexed: 08/15/2023]
Abstract
BACKGROUND Manganese (Mn) is essential to healthy neurodevelopment, but both Mn deficiency and over-exposure have been linked to prefrontal cortex (PFC) impairments, the brain region that regulates cognitive and neurobehavioral processes responsible for spatial memory, learning, motivation, and time perception. These processes facilitated by attention, inhibitory control, working memory, and cognitive flexibility are often sexually dimorphic and complex, driven by multiple interconnected neurologic and cognitive domains. OBJECTIVE We investigated the role of child sex as an effect modifier of the association between prenatal Mn exposure and performance in an operant testing battery (OTB) that assessed multiple cognitive and behavioral functional domains. METHODS Children (N = 575) aged 6-8 years completed five OTB tasks. Blood and urinary Mn measurements were collected from mothers in the 2nd and 3rd trimesters. Multiple regression models estimated the association between Mn biomarkers at each trimester with OTB performance while adjusting for socio-demographic covariates. Covariate-adjusted weighted quantile sum (WQS) regression models were used to estimate the association of a Mn multi-media biomarker (MMB) mixture with OTB performance. Interaction terms were used to estimate modification effect by child sex. RESULTS Higher blood Mn exposure was associated with better response rates (more motivation) on the progressive ratio task and higher overall accuracy on the delayed matching-to-sample task. In the WQS models, the MMB mixture was associated with better response rates (more motivation) on the progressive ratio task. Additionally, for the linear and WQS models, we observed a modification effect by child sex in the progressive ratio and delayed matching-to-sample tasks. Higher prenatal Mn biomarker levels were associated with improved task performance for girls and reduced performance in boys. CONCLUSION Higher prenatal blood Mn concentrations and the MMB mixture predicted improved performance on two of five operant tasks. Higher prenatal Mn concentrations regulated executive functions in children in a sexually dimorphic manner. Higher prenatal Mn exposure is associated with improved performance on spatial memory and motivation tasks in girls, suggesting that Mn's nutritional role is sexually dimorphic, and should be considered when making dietary and/or environmental intervention recommendations.
Collapse
Affiliation(s)
- Jamil M Lane
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Paul Curtin
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - John J Chelonis
- Division of Neurotoxicology, National Center for Toxicological Research, FDA, Jefferson, AR, USA
| | - Ivan Pantic
- Division of Community Interventions Research, National Institute of Perinatology, Mexico City, Mexico
| | - Sandra Martinez-Medina
- Division of Community Interventions Research, National Institute of Perinatology, Mexico City, Mexico
| | - Martha M Téllez-Rojo
- Center for Nutrition and Health Research, National Institute of Public Health, Cuernavaca, Morelos, Mexico
| | - Robert O Wright
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Institute for Exposomic Research, Icahn School of Medicine at Mount Sinai, USA
| |
Collapse
|
3
|
Lane JM, Liu SH, Pantic I, Martinez-Medina S, Téllez-Rojo MM, Amarasiriwardena C, Wright RO. Sex-specific association between prenatal manganese exposure and working memory in school-aged children in Mexico city: An exploratory multi-media approach. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 333:121965. [PMID: 37286025 PMCID: PMC10527609 DOI: 10.1016/j.envpol.2023.121965] [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: 02/28/2023] [Revised: 05/11/2023] [Accepted: 06/04/2023] [Indexed: 06/09/2023]
Abstract
It remains unclear whether manganese (Mn) exposure affects working memory (WM) in a sexually dimorphic manner. Further, no gold standard media exists to measure Mn, suggesting a combined blood and urinary Mn index may better capture the totality of exposure. We investigated the modification effect of child sex on the influence of prenatal Mn exposure on WM in school-age children, exploring two methodological frameworks to integrate exposure estimates across multiple exposure biomarkers. Leveraging the PROGRESS birth cohort in Mexico City, children (N = 559) ages 6-8 completed the between errors and strategy measures of the CANTAB Spatial Working Memory (SWM) task. Mn levels were assayed in blood and urine of mothers during the 2nd and 3rd trimesters and in umbilical cord blood from mothers and children at delivery. Weighted quantile sum regression estimated the association of a multi-media biomarker (MMB) mixture with SWM. We applied a confirmatory factor analysis to similarly quantify a latent blood Mn burden index. We then used an adjusted linear regression to estimate the Mn burden index with SWM measures. Interaction terms were used to estimate the modification effect by child sex for all models. Results showed that the between-errors-specific MMB mixture (i.e., this model demonstrates the impact of the MMB mixture on the between-error scores.) was associated (β = 6.50, 95% CI: 0.91, 12.08) with fewer between errors for boys and more between errors for girls. The strategy-specific MMB mixture (i.e., this model demonstrates the impact of the MMB mixture on the strategy scores) was associated (β = -1.36, 95% CI: 2.55, - 0.18) with less efficient strategy performance for boys and more efficient strategy performance for girls. A higher Mn burden index was associated (β = 0.86, 95% CI: 0.00, 1.72) with more between errors in the overall sample. The vulnerability to prenatal Mn biomarkers on SWM differs in the directionality by child sex. An MMB mixture and composite index of body burden are stronger predictors than a single biomarker for Mn exposure on WM performance.
Collapse
Affiliation(s)
- Jamil M Lane
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Shelley H Liu
- Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Ivan Pantic
- Division of Community Interventions Research, National Institute of Perinatology, Mexico City, Mexico
| | - Sandra Martinez-Medina
- Division of Community Interventions Research, National Institute of Perinatology, Mexico City, Mexico
| | - Martha M Téllez-Rojo
- Center for Nutrition and Health Research, National Institute of Public Health, Cuernavaca, Morelos, Mexico
| | - Chitra Amarasiriwardena
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Institute for Exposomic Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Robert O Wright
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Institute for Exposomic Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| |
Collapse
|
4
|
Rechtman E, Navarro E, de Water E, Tang CY, Curtin P, Papazaharias DM, Ambrosi C, Mascaro L, Cagna G, Gasparotti R, Invernizzi A, Reichenberg A, Austin C, Arora M, Smith DR, Lucchini RG, Wright RO, Placidi D, Horton MK. Early-Life Critical Windows of Susceptibility to Manganese Exposure and Sex-Specific Changes in Brain Connectivity in Late Adolescence. BIOLOGICAL PSYCHIATRY GLOBAL OPEN SCIENCE 2023; 3:460-469. [PMID: 37519473 PMCID: PMC10382697 DOI: 10.1016/j.bpsgos.2022.03.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 03/16/2022] [Accepted: 03/20/2022] [Indexed: 11/30/2022] Open
Abstract
Background Early-life environmental exposures during critical windows (CWs) of development can impact life course health. Exposure to neuroactive metals such as manganese (Mn) during prenatal and early postnatal CWs may disrupt typical brain development, leading to persistent behavioral changes. Males and females may be differentially vulnerable to Mn, presenting distinctive CWs to Mn exposure. Methods We used magnetic resonance imaging to investigate sex-specific associations between early-life Mn uptake and intrinsic functional connectivity in adolescence. A total of 71 participants (15-23 years old; 53% female) from the Public Health Impact of Manganese Exposure study completed a resting-state functional magnetic resonance imaging scan. We estimated dentine Mn concentrations at prenatal, postnatal, and early childhood periods using laser ablation-inductively coupled plasma-mass spectrometry. We performed seed-based correlation analyses to investigate the moderating effect of sex on the associations between Mn and intrinsic functional connectivity adjusting for age and socioeconomic status. Results We identified significant sex-specific associations between dentine Mn at all time points and intrinsic functional connectivity in brain regions involved in cognitive and motor function: 1) prenatal: dorsal striatum, occipital/frontal lobes, and middle frontal gyrus; 2) postnatal: right putamen and cerebellum; and 3) early childhood: putamen and occipital, frontal, and temporal lobes. Network associations differed depending on exposure timing, suggesting that different brain networks may present distinctive CWs to Mn. Conclusions These findings suggest that the developing brain is vulnerable to Mn exposure, with effects lasting through late adolescence, and that females and males are not equally vulnerable to these effects. Future studies should investigate cognitive and motor outcomes related to these associations.
Collapse
Affiliation(s)
- Elza Rechtman
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Esmeralda Navarro
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Erik de Water
- Department of Psychiatry & Behavioral Sciences, University of Minnesota, Minneapolis, Minnesota
| | - Cheuk Y. Tang
- Department of Diagnostic, Molecular, and Interventional Radiology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Paul Curtin
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Demetrios M. Papazaharias
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Claudia Ambrosi
- ASST Spedali Civili Hospital, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy
| | - Lorella Mascaro
- ASST Spedali Civili Hospital, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy
| | - Giuseppa Cagna
- Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy
| | - Roberto Gasparotti
- Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy
| | - Azzurra Invernizzi
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Abraham Reichenberg
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, New York
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Christine Austin
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Manish Arora
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Donald R. Smith
- Department of Microbiology and Environmental Toxicology, University of California Santa Cruz, Santa Cruz, California
| | - Roberto G. Lucchini
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, New York
- Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy
- Department of Environmental Health Sciences, Robert Stempel College of Public Health and Social Work, Florida International University, Miami, Florida
| | - Robert O. Wright
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Donatella Placidi
- Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy
| | - Megan K. Horton
- Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, New York
| |
Collapse
|
5
|
Associations between Elemental Metabolic Dynamics and Default Mode Network Functional Connectivity Are Altered in Autism. J Clin Med 2023; 12:jcm12031022. [PMID: 36769671 PMCID: PMC9917994 DOI: 10.3390/jcm12031022] [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: 12/05/2022] [Revised: 01/24/2023] [Accepted: 01/27/2023] [Indexed: 01/31/2023] Open
Abstract
Autism is a neurodevelopmental condition associated with atypical social communication, cognitive, and sensory faculties. Recent advances in exposure biology suggest that biomarkers of elemental uptake and metabolism measured in hair samples can yield an effective signal predictive of autism diagnosis. Here, we investigated if elemental biomarkers in hair were associated with functional connectivity in regions of the default mode network (DMN) previously linked to autism. In a study sample which included twin pairs with concordant and discordant diagnoses for autism, our analysis of hair samples and neuroimaging data supported two general findings. First, independent of autism diagnosis, we found a broad pattern of association between elemental biomarkers and functional connectivity in the DMN, which primarily involved dynamics in zinc metabolism. Second, we found that associations between the DMN and elemental biomarkers, particularly involving phosphorus, calcium, manganese, and magnesium, differed significantly in autistic participants from control participants. In sum, these findings suggest that functional dynamics in elemental metabolism relate broadly to persistent patterns of functional connectivity in the DMN, and that these associations are altered in the emergence of autism.
Collapse
|
6
|
Ruiz-Azcona L, Markiv B, Expósito A, Pozueta A, García-Martínez M, Fernández-Olmo I, Santibáñez M. Poorer cognitive function and environmental airborne Mn exposure determined by biomonitoring and personal environmental monitors in a healthy adult population. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 815:152940. [PMID: 35007600 DOI: 10.1016/j.scitotenv.2022.152940] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 12/15/2021] [Accepted: 01/02/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND/AIM In the Santander Bay (Cantabria, northern Spain), a ferromanganese alloy plant is located. Our objective was to characterize the Mn personal exposure of adult healthy volunteers living in this highly Mn exposed region, and to determine its association with a poorer cognitive function. METHODS Cross-sectional study analyzing 130 consecutive participants. Cognitive function was assessed by Stroop Color Word, Verbal Fluency tests, Trail Making Test (TMT), Digit Span (WAIS III) and Rey Osterrieth Complex Figure (ROCF) tests and crude scores were standardized according to NEURONORMA norms. Exposure to Mn was assessed in terms of source distance, by Personal Environmental Monitors (PEMs) allowing the separation of fine (PM2.5) and coarse (PM10-2.5) particles (obtaining the bioaccessible fraction by in-vitro bioaccessibility tests), and by biomarkers (blood, hair and fingernails). Age, sex, study level and number of years of residence were predefined as confounding variables and adjusted Mean Differences (MDs) were obtained. RESULTS Statistically significant lower scores (negative MDs) in all test were observed when living near the industrial emission source, after adjusting for the predefined variables. Regarding PEMs results, statistically significant lower scores in all Stroop parts were obtained in participants with higher levels of Total Mn in All fractions (PM10). For Verbal Fluency tests, negative MDs were obtained for both bioaccessible fractions. Digit Span Backward scores were lower for those with higher levels in the bioaccessible coarse fraction, and negative MDs were also observed for the ROCF Delayed part and the non-bioaccessible fine fraction. As regards to Mn in fingernails, adjusted MDs of -1.60; 95%CI (-2.57 to -0.64) and -1.45; 95%CI (-2.29 to -0.61) for Digit Span Forward and Backward parts were observed. CONCLUSIONS Our results support an association between poorer cognitive function and environmental airborne Mn exposure.
Collapse
Affiliation(s)
- Laura Ruiz-Azcona
- Global Health Research Group. Dpto Enfermería, Universidad de Cantabria, Avda. Valdecilla, s/n., 39008 Santander, Cantabria, Spain
| | - Bohdana Markiv
- Dpto. de Ingenierías Química y Biomolecular, Universidad de Cantabria, Avda. Los Castros s/n, 39005 Santander, Cantabria, Spain
| | - Andrea Expósito
- Dpto. de Ingenierías Química y Biomolecular, Universidad de Cantabria, Avda. Los Castros s/n, 39005 Santander, Cantabria, Spain
| | - Ana Pozueta
- Service of Neurology, IDIVAL, University Hospital Marqués de Valdecilla, University of Cantabria, 39008 Santander, Spain; CIBERNED, Network Center for Biomedical Research in Neurodegenerative Diseases, 28031 Madrid, Spain
| | - María García-Martínez
- Service of Neurology, IDIVAL, University Hospital Marqués de Valdecilla, University of Cantabria, 39008 Santander, Spain; CIBERNED, Network Center for Biomedical Research in Neurodegenerative Diseases, 28031 Madrid, Spain
| | - Ignacio Fernández-Olmo
- Dpto. de Ingenierías Química y Biomolecular, Universidad de Cantabria, Avda. Los Castros s/n, 39005 Santander, Cantabria, Spain
| | - Miguel Santibáñez
- Global Health Research Group. Dpto Enfermería, Universidad de Cantabria, Avda. Valdecilla, s/n., 39008 Santander, Cantabria, Spain; Nursing Research Group, IDIVAL, Calle Cardenal Herrera Oria s/n, 39011 Santander, Cantabria, Spain.
| |
Collapse
|
7
|
Abstract
PURPOSE OF REVIEW At elevated levels, the essential element manganese (Mn) is neurotoxic and increasing evidence indicates that environmental Mn exposure early in life negatively affects neurodevelopment. In this review, we describe how underlying genetics may confer susceptibility to elevated Mn concentrations and how the epigenetic effects of Mn may explain the association between Mn exposure early in life and its toxic effects later in life. RECENT FINDINGS Common polymorphisms in the Mn transporter genes SLC30A10 and SLC39A8 seem to have a large impact on intracellular Mn levels and, in turn, neurotoxicity. Genetic variation in iron regulatory genes may to lesser extent also influence Mn levels and toxicity. Recent studies on Mn and epigenetic mechanisms indicate that Mn-related changes in DNA methylation occur early in life. One human and two animal studies found persistent changes from in utero exposure to Mn but whether these changes have functional effects remains unknown. Genetics seems to play a major role in susceptibility to Mn toxicity and should therefore be considered in risk assessment. Mn appears to interfere with epigenetic processes, potentially leading to persistent changes in developmental programming, which warrants further study.
Collapse
|