Mortality and cancer incidence in a Swedish art glassworks - an updated cohort study

Aim: To study mortality and cancer incidence, in a Swedish art glassworks producing both heavy and semi-crystal glassware, in an extended cohort of workers over a long time period during which some preventive actions had taken place. Methods: In the updated study, 1,229 men and women were eligible as cohort members during the period 1964-1997. The observed number of cases was compared with expected numbers, as calculated from cause-, age-, gender- and calendar year-specific national rates for mortality and cancer incidence. Results: Among men only, a significant risk was seen for cancer incidence in the colon and rectum [standardised incidence ratio (SIR) 1.92, 95% confidence interval (CI) 1.05-3.23; 14 cases] and increased, but statistically nonsignificant, risks were also seen for male cases of tumours in the liver/bile ducts and brain. Among women, statistically non-significant risks were seen for tumours in the liver/bile ducts and in the lymphatic and haematopoietic systems. No increased risk for cancer of the lung was found in this updated study. The risk for cancer in the colon/rectum was slightly increased in all work categories, and the increase was statistically significant among male and female unspecified glassworkers (SIR 3.13, 95% CI 1.35-6.16; five male and three female cases). A statistically significantly increased risk for cancer in the liver/bile ducts was seen among refinement workers (SIR 3.96, 95% CI 1.07-10.14; two male and two female cases). Conclusion: Most of the causes of death associated with an elevated standardised mortality ratio (SMR) in the 1985 cohort resulted in lower SMRs in this updated cohort, maybe as a consequence of preventive actions taken at the glassworks. On the other hand, the risk for cancers in the digestive system seems to remain, perhaps due to past asbestos exposure or inhalation/digestion of larger particles in the ambient air.