Changes in cellular immunity among workers occupationally exposed to styrene in a plastics lamination plant

Background Styrene is a widely used industrial chemical. Immune and hematol ogical parameters were examined in 29 hand laminators and sprayers exposed to styrene for an average of 14 years and in 19 in-factory unexposed contro ls. The workers performed hand lamination procedures in a production area w ith ail average area airborne styrene level of 139.5 mg/m(3). Mean concentr ation of styrene in the blood of exposed workers was 945.7 mu g/L and the m ean styrene in exhaled air was 38.8 mu g/L. Methods Parameters of internal and external exposure, immune function assay s, immunoglobulins, acute phase reactants and hematology were evaluated in exposed and non-exposed populations. Results Using multifactorial analysis of variance Mle found a significant d ecrease in proliferation of lymphocytes stimulated by Concanavalin A but no t by pokeweed mitogen (PWM) in workers occupationally exposed to styrene. P roliferative response to PWM was significantly correlated with the levels o f styrene irt blood. Phagocytic activity of monocytes, levels of IgG, IgA, IgM, IgE and alpha-2-macroglobulin in serum were indistinguishable in the t wo groups. The population exposed to styrene had increased levels of C4-com ponent of complement. Levels of C3-component of complement were positively correlated with duration of exposure. A significant elevation in the percen tage and number of monocytes and a significantly decreased number of lympho cytes were seen in exposed workers. Styrene concentrations in both blood an d exhaled air were associated with decreased percentage of large granular l ymphocytes. Conclusions These results suggest immune alterations of cell-mediated immun e response of T-lymphocytes and imbalance in leucocyte subsets in periphera l blood of workers exposed to styrene. (C) 2000 Wiley-Liss, Inc.