O-287 Occupational exposures of firefighting and urinary tract cancer risk among men in the Norwegian fire departments cohort

Introduction

We observed elevated incidence of urinary tract cancer (UTC; ICD10 C65–68) among Norwegian male firefighters in previous studies. Increased risk of bladder cancer (C67), alongside mesothelioma, was the main evidence for the recent re-classification of firefighting as carcinogenic (Group 1) by the International Agency for Research on Cancer. However, the exposure-response associations remain unclear.

Objectives

We aimed to develop detailed indicators for exposures of firefighting and more closely examine the previously observed elevated risk of UTC, including bladder cancer.

Materials and Methods

Indicators were developed for exposure to fire/smoke and diesel exhaust using data on fire and emergency responses from the Norwegian Directorate for Civil Protection, and on working conditions at 15 fire departments. Using work history data available for 4250 men in the Norwegian Fire Departments Cohort, the time-dependent sum of these exposure indicators was determined according to each individual’s annual employment percentage and exposure potential of position(s) held. Incident UTCs occurring during follow-up (1960–2021) were obtained from the Cancer Registry of Norway, and Poisson regression was used to estimate incidence rate ratios and 95% confidence intervals. This study has been approved by the Regional Committee for Medical and Health Research Ethics South-East Norway.

Results

During 125,090 person-years of follow-up, there were 76 cases of UTC. Exposure indicators hypothesized to be of greatest significance to UTC risk include those for polycyclic aromatic hydrocarbons and diesel exhaust, as well as the influence of improvements in protective equipment and working conditions. Preliminary results from ongoing regression analyses point to positive exposure-response associations and will be presented.

Conclusion

Detailed exposure indicators were developed using information on working conditions that is rarely available in other studies. We hope to contribute to a better understanding of the potential roles of different exposures on the increased risk of UTC among firefighters.