Evaluation of occupational exposure to metal dust on the liver of road construction workers in Abuja metropolis

Increasing air pollution levels due to rapid urbanization and growth in infrastructural facilities coupled with low level of standard safety procedures have been observed in Nigeria, and become a major source of concern. The study evaluated the effects of occupational exposure to metal dust on the liver of road construction workers in Abuja metropolis. Blood samples were used in the measurement of Lead, cadmium, magnesium and iron as indicators for metal toxicity. Bilirubin, liver enzymes (aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatise (ALP)) and proteins as biomarkers for liver function. Samples were collected from different road construction sites. One hundred (n = 100) subjects were recruited and served as the exposed group and another one hundred (n = 100) control as unexposed (control) group. Samples were analyzed using Atomic Absorption Spectrometry for the toxic metals (Lead and Cadmium) and trace elements (Magnesium and Iron); and Selectra ProS Clinical Chemistry Auto Analyzer for the liver function tests respectively. This study showed a statistically significant increase in Lead, Magnesium and Iron (p<0.001) when exposed subjects were compared with unexposed subjects. Test for liver function showed a significant reduction in total bilirubin (p<0.01) and direct bilirubin (p<0.05) respectively. Albumin also show statistically significant increase (p<0.05) on comparison of exposed and unexposed subjects. This study indicates the presence of metal dust in road construction workers occupationally exposed, and suggestive of liver impairment following continued exposure to these toxic metals and trace elements.   Key words: Occupational exposure, metal dust, liver.