Welding-related brain and functional changes in welders with chronic and low-level exposure

Eun Young Lee, Michael R. Flynn, Mechelle Lewis, Richard Mailman, Xuemei Huang

Research output: Contribution to journalArticle

2 Citations (Scopus)

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 90 days 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.

Original languageEnglish (US)
Pages (from-to)50-59
Number of pages10
JournalNeuroToxicology
Volume64
DOIs
StatePublished - Jan 1 2018

Fingerprint

Welding
Manganese
Brain
Basal Ganglia
Magnetic resonance imaging
Globus Pallidus
Poisons
Anisotropy
Police
Law enforcement
Public health
Occupations
Nutrients
Uncertainty
Tensors
Cohort Studies

All Science Journal Classification (ASJC) codes

  • Neuroscience(all)
  • Toxicology

Cite this

@article{177ff2465df04b0aa3e13a1cf9113885,
title = "Welding-related brain and functional changes in welders with chronic and low-level exposure",
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 90 days 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.",
author = "Lee, {Eun Young} and Flynn, {Michael R.} and Mechelle Lewis and Richard Mailman and Xuemei Huang",
year = "2018",
month = "1",
day = "1",
doi = "10.1016/j.neuro.2017.06.011",
language = "English (US)",
volume = "64",
pages = "50--59",
journal = "NeuroToxicology",
issn = "0161-813X",
publisher = "Elsevier",

}

Welding-related brain and functional changes in welders with chronic and low-level exposure. / Lee, Eun Young; Flynn, Michael R.; Lewis, Mechelle; Mailman, Richard; Huang, Xuemei.

In: NeuroToxicology, Vol. 64, 01.01.2018, p. 50-59.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Welding-related brain and functional changes in welders with chronic and low-level exposure

AU - Lee, Eun Young

AU - Flynn, Michael R.

AU - Lewis, Mechelle

AU - Mailman, Richard

AU - Huang, Xuemei

PY - 2018/1/1

Y1 - 2018/1/1

N2 - 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 90 days 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.

AB - 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 90 days 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.

UR - http://www.scopus.com/inward/record.url?scp=85021244281&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85021244281&partnerID=8YFLogxK

U2 - 10.1016/j.neuro.2017.06.011

DO - 10.1016/j.neuro.2017.06.011

M3 - Article

C2 - 28648949

AN - SCOPUS:85021244281

VL - 64

SP - 50

EP - 59

JO - NeuroToxicology

JF - NeuroToxicology

SN - 0161-813X

ER -