[Study on relationships between biomarkers in workers with low-level occupational lead exposure]

Area of Science:

• Environmental Health
• Occupational Medicine
• Toxicology

Background:

• Occupational lead exposure poses significant health risks, particularly in industries like lead-acid battery manufacturing.
• Understanding the relationships between various biomarkers is crucial for assessing lead exposure and its health impacts.

Purpose of the Study:

• To investigate lead exposure levels and their effects in workers with low-level occupational exposure.
• To explore the relationships between biomarkers of susceptibility and their practical value in evaluating health hazards.

Main Methods:

• Occupational health monitoring was conducted to measure lead fume and dust concentrations.
• Blood and urine samples from 233 occupationally exposed and 76 non-exposed workers were analyzed for lead (Pb-B, Pb-U), zinc protoporphyrin (ZPP), and delta-aminolevulinic acid (ALA-U).
• ALAD concentration and ALAD gene polymorphism were also determined, with correlations analyzed using multiple linear regression.

Main Results:

• Blood lead (Pb-B) levels positively correlated with urine lead (Pb-U) and ZPP, and negatively with ALAD concentration.
• A significant positive correlation between Pb-B and ZPP was observed only when Pb-B levels were ≥190 µg/L.
• ALAD gene polymorphism influenced ALAD activity and ZPP levels, with differing effects between occupationally exposed and non-exposed groups.

Conclusions:

• Delta-aminolevulinic acid dehydratase (ALAD) can serve as an effective biomarker for low blood lead (Pb-B) levels.
• Zinc protoporphyrin (ZPP) correlates with Pb-B levels at higher concentrations (≥190 µg/L).
• ALAD gene polymorphism plays a role in lead toxicity and biomarker responses in occupationally exposed individuals.