[Effects of working conditions in the production of synthetic rubber on workers' health].

Examination of 325 Kazan workers engaged in the production of synthetic rubber revealed a high (35.6%) prevalence of thyroid pathology. Patients with thyroid disease and apparently healthy workers manufacturing synthetic rubber were found to have lower levels of T3, T4, and zinc and higher levels of thyroglobulin antibodies and chromium in the serum than in apparently healthy individuals not contacting with noxious agents. The magnitude of increases in the workers' serum concentration of chromium was related to the length of service. The changes were more pronounced in patients with thyroid disease. Correlation analysis revealed that there were direct relationships between the serum levels of T3, T4, and zinc in all groups. There was an inverse correlation between the levels of T4 and the length of service in noxious production in the workers with thyroid disease.