The growing scope of biotechnologic enterprises now in process necessitates provision of safe labour conditions and health protecting measures. It was suggested that the biologic factor inherent in modern industries can provoke bronchopulmonary pathologic conditions. The performed clinical studies of the immunocompetent system state in workers revealed adaptational changes in the form of phagocytic functional activity and increase in the immune complexes circulating in blood serum. Bronchoallergic patients exhibited more profound immunity disorders with a considerable decrease in T-suppressors and peripheral blood eosinophil growth. Preventive treatment with the natrium nucleinate immunomodulator was performed with a positive result.