Mortality study among Paris sewage workers

Objective: To describe the mortality of sewage workers from Paris (France).
Methods: The cohort of 1594 Paris sewage workers since 1970 was set up in 2010 and followed-up on mortality from 1970 to 2010. Vital status and causes of death were determined by matching with national databases. Standardized Mortality Ratios (SMRs) were computed using local death rates by causes of death and 10-year employment duration classes. Data are currently analysed using relative survival techniques. This study was approved by the national ethic comity.
Results: Statistically significant mortality excess was observed for all causes (SMR=1.34, 778 cases) and for cancer (SMR=1.49, 337 cases). SMRs were also statistically greater than 1 for malignant (SMR=1.74, 22 cases) and non-malignant (SMR=1.77, 43 cases) liver diseases, lung cancer (SMR=1.59, 97 cases), oesophagus cancer (SMR=2.35, 28 cases), all alcohol-related diseases (SMR=1.78, 128 cases), and suicide (SMR=3.64, 22 cases). Greater than 1 but not statistically significant SMRs were observed for infectious diseases and respiratory infectious diseases. The mortality from several diseases (all causes, all cancer, oesophagus cancer, lung cancer, chronic liver diseases, all alcohol-related diseases, and infectious diseases) increased with employment duration as a sewer worker. Except for lung cancer, the SMR for smoking-related diseases was not statistically greater than 1. Results of survival analysis are in progress.
Conclusion: The increase mortality observed for lung cancer and infectious diseases with employment duration suggests possible occupational health effect among sewer workers. Conclusions will be completed from the survival analysis.