Biomarkers for occupational manganese exposure.

Area of Science:

• Occupational Health
• Environmental Health
• Neurotoxicology

Background:

• Long-term inhalation of manganese (Mn) can lead to manganism and neurofunctional deficits.
• Workers in Mn mining, battery manufacturing, steel production, and welding are at risk.
• Biomarkers are needed to assess Mn exposure and associated health risks.

Purpose of the Study:

• To critically review the reliability of Mn exposure biomarkers.
• To examine the relationship between occupational Mn inhalation and Mn levels in biological samples.
• To assess the link between blood Mn levels and neurotoxic outcomes.

Main Methods:

• Searched three bibliographic databases for relevant studies.
• Screened 6338 unique references, retaining 76 articles for data abstraction.
• Focused on whole blood as a potential biomarker for internal Mn dose.

Main Results:

• Relationships between blood Mn and external exposure indices were limited and inconsistent.
• Heterogeneity in exposure sources and methodologies hindered direct comparisons.
• Whole blood biomarkers showed potential utility for Mn biomonitoring and risk assessment.

Conclusions:

• Current evidence on Mn biomarkers, including blood, urine, and hair, is limited and inconsistent.
• Whole blood Mn levels may be the most promising biomarker for occupational Mn exposure assessment.
• Further research with standardized methodologies is needed to clarify Mn-biomarker relationships and neurotoxic effects.