Evidence map›Paper›PMID 33008482›Full record

SynthesisEnvironmental health : a global access science source2020

Biomarkers of environmental manganese exposure and associations with childhood neurodevelopment: a systematic review and meta-analysis.

Weiwei Liu, Yongjuan Xin, Qianwen Li, Yanna Shang, Zhiguang Ping, Junxia Min, Catherine M Cahill, Jack T Rogers, Fudi Wang

Open access · goldAbstract readMeta-AnalysisSystematic Review
PubMed Full text at PMC Publisher
In one paragraph

Synthesis in Environmental health : a global access science source, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 45 papers, 2 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
45citing papers in PubMed, 2 pooled it
4.4field-weighted citation impact, top 4% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

45 citing papers in PubMed, 2 syntheses or guidelines pooled it, 80 citations in OpenAlex.

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  13. Elevated brain manganese induces motor disease by upregulating the kynurenine pathway of tryptophan metabolism.Proceedings of the National Academy of Sciences of the United States of America · 2025
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors at 3 institutions in 2 countries.

Weiwei LiuDepartment of Nutrition, Precision Nutrition Innovation Center, School of Public Health, Zhengzhou University, Zhengzhou, China.
Yongjuan XinDepartment of Nutrition, Precision Nutrition Innovation Center, School of Public Health, Zhengzhou University, Zhengzhou, China.
Qianwen LiDepartment of Nutrition, Precision Nutrition Innovation Center, School of Public Health, Zhengzhou University, Zhengzhou, China.
Yanna ShangDepartment of Nutrition, Precision Nutrition Innovation Center, School of Public Health, Zhengzhou University, Zhengzhou, China.
Zhiguang PingDepartment of Nutrition, Precision Nutrition Innovation Center, School of Public Health, Zhengzhou University, Zhengzhou, China.
Junxia MinThe First Affiliated Hospital, School of Public Health, Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, China.
Catherine M CahillNeurochemistry Laboratory, Department of Psychiatry-Neuroscience, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA.
Jack T RogersNeurochemistry Laboratory, Department of Psychiatry-Neuroscience, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA. jack.rogers@mgh.harvard.edu.
Fudi WangDepartment of Nutrition, Precision Nutrition Innovation Center, School of Public Health, Zhengzhou University, Zhengzhou, China. fwang@zju.edu.cn.ORCID 0000-0001-8730-0003
Zhengzhou University · CNHarvard University · USZhejiang University · CN

Funding

Post Transcriptional Control of hemorrhagic iron damage.R21NS077079 · NINDS · MASSACHUSETTS GENERAL HOSPITAL · PI ROGERS, JACK T · 2012 to 2013
$458k
NINDS NIH HHS R21 NS077079
6 · The paper itself

Abstract

backgroundAlthough prior studies showed a correlation between environmental manganese (Mn) exposure and neurodevelopmental disorders in children, the results have been inconclusive. There has yet been no consistent biomarker of environmental Mn exposure. Here, we summarized studies that investigated associations between manganese in biomarkers and childhood neurodevelopment and suggest a reliable biomarker.

methodsWe searched PubMed and Web of Science for potentially relevant articles published until December 31th 2019 in English. We also conducted a meta-analysis to quantify the effects of manganese exposure on Intelligence Quotient (IQ) and the correlations of manganese in different indicators.

resultsOf 1754 citations identified, 55 studies with 13,388 subjects were included. Evidence from cohort studies found that higher manganese exposure had a negative effect on neurodevelopment, mostly influencing cognitive and motor skills in children under 6 years of age, as indicated by various metrics. Results from cross-sectional studies revealed that elevated Mn in hair (H-Mn) and drinking water (W-Mn), but not blood (B-Mn) or teeth (T-Mn), were associated with poorer cognitive and behavioral performance in children aged 6-18 years old. Of these cross-sectional studies, most papers reported that the mean of H-Mn was more than 0.55 μg/g. The meta-analysis concerning H-Mn suggested that a 10-fold increase in hair manganese was associated with a decrease of 2.51 points (95% confidence interval (CI), - 4.58, - 0.45) in Full Scale IQ, while the meta-analysis of B-Mn and W-Mn generated no such significant effects. The pooled correlation analysis revealed that H-Mn showed a more consistent correlation with W-Mn than B-Mn. Results regarding sex differences of manganese associations were inconsistent, although the preliminary meta-analysis found that higher W-Mn was associated with better Performance IQ only in boys, at a relatively low water manganese concentrations (most below 50 μg/L).

conclusionsHigher manganese exposure is adversely associated with childhood neurodevelopment. Hair is the most reliable indicator of manganese exposure for children at 6-18 years of age. Analysis of the publications demonstrated sex differences in neurodevelopment upon manganese exposure, although a clear pattern has not yet been elucidated for this facet of our study.

Indexed as

BiomarkersChildChild DevelopmentEnvironmental ExposureEnvironmental PollutantsHairHumansIntelligenceManganeseNeurodevelopmental DisordersBiomarkersEnvironmental PollutantsManganeseBehaviorBiomarkerCognitive functionManganese exposureMotor

Identifiers

PMID33008482
PMCPMC7531154
OpenAlexW3090339540

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.