Objectives: The study on mortality from cancer among workers of an asbestos plant manufacturing asbestos yarn, cloth, cords, packings, stuffing, brake linings and asbestos-rubber sheets was launched in the 1980s. The present paper discusses the results of further tracing of asbestos workers of the same plant.
Materials and methods: The study cohort covered 4497 workers employed at the asbestos plant in 1945-1980. The follow-up of the cohort continued until 31 December 1999. Deaths by causes were analyzed using standardized mortality ratio (SMR) calculated by the person-years method. The mortality pattern of the general population of Poland was used as reference.
Results: The availability of the cohort was 93.1% (2805 men and 1382 women were traced). Mortality from malignant neoplasms in total (281 deaths among men, SMR = 118, 95%CI: 105-133 and 135 deaths among women, SMR = 159, 95%CI: 133-188) as well as that from lung cancer (102 deaths among men, SMR = 126, 95%CI: 103-153 and 18 deaths among women, SMR = 259, 95%CI: 153-409) were significantly higher than in the general population. Unlike earlier stages of analysis, the present study revealed an increased risk of pleural mesothelioma (2 deaths among men, SMR = 510, 95%CI: 62-1842 and 3 deaths among women, SMR = 2033, 95%CI: 419-5941). Mortality analysis among workers with asbestosis and in those without diagnosed asbestosis, did not reveal direct association between the risk of asbestos-induced lung cancer and previously diagnosed asbestosis.
Conclusions: The prolonged cohort tracing showed an increased risk of asbestos-related cancers. It concerned mainly workers hired by the plant between 1945-1955, when the working condition were most strenuous.