Changes in some liver function parameters (aspartate transaminase, alanine transaminase, alkaline phosphatase, total and conjugated bilirubin) with long term exposure to paint spray fumes in Enugu area

Occupational exposure to chemical fumes is a recognized public health concern, particularly in developing countries where workplace safety regulations are often poorly enforced. Paint spray fumes contain a complex mixture of volatile organic compounds and heavy metals capable of inducing hepatic toxicity following prolonged inhalation. This study assessed changes in selected liver function parameters among professional painters chronically exposed to painting spray fumes in Enugu, Nigeria. A total of ninety male subjects aged 21–40 years participated in the study, comprising fifty painters with long-term occupational exposure and forty apparently healthy non-painters serving as controls. Serum activities of aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), total bilirubin, and conjugated bilirubin were determined using enzymatic and colorimetric techniques. Results were expressed as mean ± standard deviation (SD). Statistical comparison between test and control groups was performed using Student’s t-test. A p-value less than 0.05 were considered statistically significant. The results showed a significant increase in AST activity among painters compared with controls (20.04 ± 7.41 IU/L verses 15.45 ± 5.54 IU/L; p = 0.002), while ALT and ALP showed no statistically significant differences between both groups (p > 0.05). Total bilirubin and conjugated bilirubin levels were significantly elevated in painters compared with controls (p < 0.05). These findings suggest that prolonged exposure to painting spray fumes may induce mild hepatocellular injury and impaired bilirubin metabolism even in the absence of marked elevation of all liver enzymes. Continuous occupational exposure to paint fumes therefore poses a potential risk to liver health. Periodic biochemical monitoring and enforcement of occupational safety measures are recommended.