Occupational Exposure to Electric Shocks and Extremely Low-Frequency Magnetic Fields and Motor Neurone Disease

A New Zealand population-based case-control study on occupational exposure to electric shocks, extremely low-frequency magnetic fields (ELF-MF) and motor neurone disease using job-exposure matrices to assess exposure.

 

American Journal of Epidemiology

Published October 2020

DOI:10.1093/aje/kwaa214 

Authors: Grace X Chen, Andrea’t Mannetje, Jeroen Douwes, Leonard H Berg, Neil Pearce, Hans Kromhout, Bill Glass, Naomi Brewer, Dave J McLean

This study assessed associations with occupational exposure to electric shocks, extremely low-frequency magnetic fields (ELF-MF) and motor neurone disease using job-exposure matrices to assess exposure.  New Zealand participants were recruited between 2013 and 2016. Associations with ever/never, duration, and cumulative exposure were assessed using logistic regression adjusted for age, sex, ethnicity, socioeconomic status, education, smoking, alcohol consumption, sports, head or spine injury and solvents, and mutually adjusted for the other exposure. All analyses were repeated stratified by sex. An elevated risk was observed for having ever worked in a job with potential for electric shocks (odds ratio (OR)=1.35, 95% confidence interval (CI): 0.98, 1.86), with the strongest association for the highest level of exposure (OR=2.01, 95%CI: 1.31, 3.09). Analysis by duration suggested a non-linear association: risk was increased for both short-duration (<3 years) (OR= 4.69, 95%CI: 2.25, 9.77) and long-duration in a job with high level of electric shock exposure (>24 years; OR=1.88; 95%CI: 1.05, 3.36), with less pronounced associations for intermediate durations. No association with ELF-MF was found. The findings provide support for an association between occupational exposure to electric shocks and motor neurone disease but did not show associations with exposure to work-related ELF-MF.

The full article is available here

Rose Centre for Stroke Recovery and Research

Researchers

Paige Thomas, PhD Candidate  (photo provided)
Rose Centre for Stroke Recovery and Research
Department of Communication Disorders
University of Canterbury, Christchurch

Primary Supervisor: Prof. Maggie Lee Huckabee
Director of the Rose Centre for Stroke Recovery and Research
Department of Communication Disorders
University of Canterbury, Christchurch

Current Research

Paige and the team have conducted a proof of concept study to assess the impact of swallowing skill training protocol in patients with Amyotrophic Lateral Sclerosis (ALS).

Currently, patients with ALS are not considered candidates for rehabilitation of swallowing; this is therefore early research into the possible benefits of rehabilitation.

Paige Thomas

The therapy is a skill training protocol for swallowing through the Biofeedback in Strength and Skill Training (BiSSkiT) software. This protocol uses surface electromyography (sEMG) which measures muscle activity from the skins surface and displays it on a computer monitor. SEMG electrodes are placed over the submental muscles which contract during swallowing resulting in a peak in the waveform on the screen. With the use of sEMG, participants are able to visualise and alter their muscle activity while swallowing. To make this task challenging, a target box will appear in a random position on the screen and participants will attempt swallow so that the peak of their swallow waveform lands within the target box. This challenging aspect of the therapy is intended to help to encourage cortical control of swallowing.

Paige and her team completed the study towards the end of 2020 and are now writing up papers for publication. In the meantime Paige has provided a summary of the study and its results for the MND Research network.  Impact of swallowing skill training protocol in patients with ALS (summary).

Relationship to MND

The research investigates prolonging functional swallowing and quality of life in patients with the Amyotrophic Lateral Sclerosis type of Motor Neuron Disease.

Future Research

The current research is a proof of concept study. Further research will be conducted into swallowing therapy in patients with ALS.

Collaborations

Paige and the team are collaborating with Dr. Sebastian Doeltgen from Flinders University and Dr. Deanna Britton from Portland State University, who is consulting on this project.

Resources

The MND Patient Registry and MND New Zealand are assisting with participant recruitment.

Resource Gaps

More funding for MND research would help to increase both the quantity and quality of MND research in New Zealand.

The Team

Prof. Maggie-Lee Huckabee, senior supervisor of research project, oversees all stages of planning and development of research as well as data collection and analysis. Director of the Rose Centre for Stroke Recovery and Research, University of Canterbury.

Dr. Phoebe Macrae, co-supervisor of research project. Deputy Director of the Rose Centre for Stroke Recovery and Research, University of Canterbury.

Dr. Michelle Troche, associate supervisor of research project, will oversee data collection in New York. Director of the Laboratory for the Study of Upper Airway Dysfunction, Columbia University.

Emma Burnip, Co-investigator, PhD candidate, performing data collection in New Zealand. Rose Centre for Stroke Recovery and Research, University of Canterbury.

The Rose Centre

Contact

The University of Canterbury Rose Centre for Stroke Recovery and Research

Leinster Chambers, Level One, 249 Papanui Road

Christchurch 8140

New Zealand

Paige Thomas

e: paige.thomas.92@gmail.com

Prof. Maggie-Lee Huckabee

p: +64 3 369 5124

e: Maggie-lee.huckabee@canterbury.ac.nz

Centre for Public Health Research

Grace Chen

 

Researchers

Grace Chen, Research Officer, PhD Candidate, Centre for Public Health Research, College of Health, Massey University.

Dr Dave McLean, Principal Investigator and Grace Chen’s supervisor

Professor Jeroen Douwes, Head of Department and Grace Chen’s supervisor

Professors Neil Pearce and Leonard van den Berg – overseas collaborators

Current Research

Grace and the team are conducting a New Zealand population based control study to investigate associations between occupational and environmental exposures and MND.

They have examined associations with occupational exposures to electric shocks, low-frequency magnetic fields, pesticides, other chemicals, and Motor Neurone Disease. They have published papers on their findings to date. See the links to these articles under publications below.

 

 

Relationship to MND

The aim of the study is to determine the relationship between MND and a range of unknown or suspected occupational and environmental exposures in New Zealand.

Future Research

The intention is to do more studies on MND after this study result has been published.

Collaborations

The Motor Neuron Disease Association New Zealand supports the recruitment for MND patients. The study also collaborated with the Centre for Brain Research (Scotter Lab) for the selected markers of the disease process.

Resources

Currently not using any shared resources, will share the database of the bio-markers of the disease process in New Zealand.

Resource Gaps

A formal diagnosis letter on the type of MND will help us to have a complete picture of the disease in New Zealand.

Publications

Sports and trauma as risk factors for Motor Neurone Disease: New Zealand case–control study.

Chen, GX, Douwes, J, van den Berg, LH, Glass, B, McLean, D, ’t Mannetje, AM. Sports and trauma as risk factors for Motor Neurone Disease: New Zealand case–control study. Acta Neurol Scand. 2022; 145: 770– 785. doi:10.1111/ane.13615 

Occupational exposures to pesticides and other chemicals: a New Zealand motor neuron disease case–control study

Chen GX, Douwes J, van den Berg L, et al. Occupational exposures to pesticides and other chemicals: a New Zealand motor neuron disease case–control study. Occupational and Environmental Medicine Published Online First: 22 March 2022. doi: 10.1136/oemed-2021-108056    

Occupational Exposure to Electric Shocks and Extremely Low-Frequency Magnetic Fields and Motor Neurone Disease 

Chen, G., McLean, D., Mannetje, A., D’Souza, W., McConnell, M., Kromhout, H., . . . Vermeulen, R. (2016). P203 Occupational exposure to ELF-MF and electric shocks and motor neurone disease. Occupational and Environmental Medicine, 73(Suppl 1), A189-A189. doi:10.1136/oemed-2016-103951.519   

 

 

 

Contact Details

Centre for Public Health Research
Massey University
Wellington Campus
PO Box 756
Wellington 6140

e: g.chen1@massey.ac.nz
w: www.publichealth.massey.ac.nz
p: +64 4 801 5799 (63121) or +64  4 9793121