Humoral immunosuppression in men exposed to polycyclic aromatic hydrocarbons and related carcinogens in polluted environments.

We evaluated humoral immunity by measuring IgG, IgA, IgM, and IgE concentrations in 274 male workers in an iron foundry in Cracow, Poland. There were two groups: 199 coke oven workers and 76 cold-rolling mill workers. The groups were similar with respect to age, length of work (average 15 years), and smoking habits. Exposure to polycyclic aromatic hydrocarbons (PAHs), assessed by personal and area monitoring, ranged from 0.2 to 50 micrograms/m3 benzo[a]pyrene in coke plant workers and was of 3-5 magnitudes higher than in the cold-rolling mill employees. Comparison of the two groups revealed a marked depression of mean serum IgG and IgA in coke oven workers (p < 0.001, Student's unpaired t-test). In the same subjects, serum IgM had a tendency to decrease, whereas serum IgE showed a trend toward higher values. Thus, workers exposed chronically to complex mixtures of air pollutants, composed primarily of PAHs, develop immunosuppression. It remains to be established whether the immunosuppression described here is related to the frequent development of lung cancer reported in coke plant employees. Workers exposed chronically to PAHs should have serum immunoglobulins monitored regularly.