Occupational Exposures and Neurodegenerative Diseases-A Systematic Literature Review and Meta-Analyses

Area of Science:

• Neuroscience
• Occupational Health
• Environmental Epidemiology

Background:

• Neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS), Alzheimer's disease (AD), and Parkinson's disease (PD), pose significant public health challenges.
• Occupational exposures to environmental factors are increasingly recognized as potential contributors to these conditions.
• Previous research has suggested links between specific exposures and neurodegenerative diseases, necessitating comprehensive analysis.

Purpose of the Study:

• To conduct an integrated and stratified meta-analysis examining occupational exposure to electromagnetic fields (EMFs), metals, and pesticides.
• To assess the association between these exposures and the risk of developing ALS, AD, and PD.
• To investigate potential publication bias in the existing literature.

Main Methods:

• Updated meta-analyses based on 66 original publications adhering to MOOSE and GRADE guidelines.
• Stratified meta-analyses were performed by publication year, statistical precision of relative risk (RR) estimates, and funnel plot analysis.
• Assessment of publication bias using established statistical tests.

Main Results:

• Occupational pesticide exposure was associated with a significantly increased risk for ALS (RR 1.35), AD (RR 1.50), and PD (RR 1.66).
• Occupational lead exposure showed an elevated risk for ALS and PD (RR 1.57), while other metal exposures did not demonstrate a significant association.
• Occupational EMF exposure was linked to a modest increased risk for ALS (RR 1.26) and AD (RR 1.33), but not for PD.

Conclusions:

• Pesticide exposure is associated with at least a 50% increased risk of developing the studied neurodegenerative diseases.
• Lead exposure demonstrated a 50% increased risk for ALS and PD.
• Occupational EMF exposure may be associated with a 10% increased risk for ALS and AD.