Decreased immune status in Nigerian workers occupationally exposed to lead

Some immunological indices of 80 Nigerian lead workers were assessed. The mean blood lead level (BLL) in the study subjects was significantly higher than in control non-exposed subjects (p < 0.001). The mean values for total globulins and C-reactive protein (CRP) were also significantly raised in the test subjects. (P < 0.001, P < 0.01 respectively). In contrast, levels of IgA and IgT were significantly depressed (P < 0.01, P, 0.001 respectively). Furthermore, a significant negative correlation was established between IgA and BLL (r = 0.28 P < 0.009). Ascorbate excretion was also significantly reduced in the exposed workers when compared with control subjects. (P < 0.02) Multiple regression analysis established significant interaction between BLL and total globulin and IgA I(P < 0.01, P < 0.01, 0.28 and P < 0.009 respectively). Principal component analysis showed that CRP, TLC, IgA and IgC have strong interactions with BLL. These data suggest depressed immune status in workers occupationally exposed to lead. This clinical state may be modulated by genetic and nutritional factors (such as ascorbate level). The control population was made up of 50 volunteers who had never been exposed to lead. Their mean age was 36.6 (semi 1.2 range 22-58) years. Informed consent was obtained from all 130 subjects and the ethical committee of the college of Medicine Ibadan, approved the conduct of the study. Additionally, it may predispose the subjects to increased susceptibility to infectious diseases, inflammatory disorders and cancer.