Objectives Mesothelioma incidence increased in Sweden between years 1970 and 2000, and seems to have reached a plateau in the last decade. We used data from the Swedish component of the Nordic Occupational Cancer Study - NOCCA - to study potential occupational exposures other than asbestos that may be associated with mesothelioma occurrence in men and women.

Methods Follow up was done by linkages of the Swedish NOCCA study database, including 53 occupational categories, with the population based Swedish registries (cancer, mortality, total population) from years 1961 to 2009, and matched with the Swedish version of NOCCA-JEM, which include 25 carcinogenic substances with exposure levels for 283 occupations in different employment periods from year 1945 to1994. Multivariate analysis with 20 years delay for cumulative exposure were done.

Results A total of 4180 incident mesothelioma of the peritoneum and pleura were reported to the Swedish Cancer Registry (1961 - 2009): 26.6% were women. 83.9% were located in the pleura (18% women). We found a significant over risk in mesothelioma in 16 of 53 occupational categories, and a clear gender difference. We observed increased risk of mesothelioma among female textile workers, building cleaners, seamstresses, printers, packers and postal workers. Men had over risks in construction workers, electricians, masons, and insulation workers; the greatest excess risk of pleural mesothelioma was observed among plumbers (SIR 5.1, 95% CI 4.30 to 6.01). In multivariate analysis, controlling for other occupational exposures, significant associations were observed for asbestos exposure and mesothelioma risk.

Conclusion Exposure to asbestos is associated with incidence of mesothelioma in Sweden. There were some occupations however, such as for female textile workers and cleaners, where we observed an increased risk of mesothelioma without evidence of exposure to asbestos.