Exposure-related risks of cancer in Norwegian offshore petroleum industry workers

Exploration of petroleum on the Norwegian continental shelf started in the mid-1960s. The first oil was produced in 1971, and the activity expanded rapidly throughout the 1980s. By the end of 2016, 80 petroleum fields were in production. Offshore workers face a hostile natural environment, which challenges safety and protection of workers' health. Chemicals in raw oil, in additives, and in emissions may increase the risk of long-term chronic diseases such as cancer. In this project, we will describe cancer risk among 28 000 individuals who have reported offshore work between 1965 and 1998. We will explore exposure-related risks, using information on new cancer cases diagnosed after 1998, registered by the Cancer Registry of Norway, and using expert estimates on chemical exposures offshore, developed at the University of Bergen. Earlier studies have shown that women, who constitute 10 percent of Norwegian offshore workers, are at increased risk of cancer when all types are taken together, involving leukaemia, malignant melanoma, and lung cancer. The project has shown an association between sun-tanning habits and skin cancer risk among women and men. Other studies among female offshore workers include exploring the association between shift work and the risk of breast cancer. Risk of respiratory cancer (lung and pleura) will also be explored among men, according to occupational exposures with adjustment for smoking and work outside the offshore sector. Cancer of the urinary bladder is in excess among male offshore workers, and we will explore the relationship between known or suspected carcinogens and urinary tract cancers. Cancer occurs in all segments of any population, and the project will compare the risk in offshore workers with that of the general population. In-depth analyses will be conducted to identify potential differences in risk between offshore workers with different levels of exposure. The project has found an association between hydrocarbon exposure and bladder cancer risk in 2023, which is a new and important finding. The project will last until the September 2024, involving a team of one post-doctoral and two doctoral research fellows. Scientific supervision will come from the Cancer Registry of Norway, University of Bergen, University of Oslo, and international experts on cancer causes and control.

Offshore petroleum work takes place under hostile conditions, which challenge the safety and the protection of workers' health. Carcinogens in raw oil, in additives, and in emissions may create situations with increased risk of long-term chronic diseases such as cancer. The project will describe cancer risk among 28 000 individuals who have reported work offshore between 1965 and 1998, with information on new cancer cases from the subsequent two decades. Experts at the University of Bergen have developed estimates of exposure to chemicals offshore, and the project team will use national data from the Cancer Registry of Norway to explore exposure-related risks of cancer. Earlier studies among Norwegian offshore workers have shown that women, who constitute 10 percent of the workers, are at increased risk of cancer of all types taken together, involving leukaemia, malignant melanoma, and lung cancer. The risk of respiratory cancer (lung and pleura) will also be explored, specifically among men, in light of occupational exposures and adjustment for smoking habits and work outside the offshore sector. Finally, cancer of the urinary bladder is in excess among male offshore workers, and the study will explore the relationship between urinary tract carcinogens and the risk of bladder cancer and kidney cancer. Cancer disease exists in all segments of any population, and the project will compare the risk in offshore workers with that of the general populace. Important in-depth analyses will be conducted to identify potential differences in risk between subgroups of offshore workers with different levels of exposure. The project is expected to last through year 2024, involving a team of one post-doctoral and two doctoral research fellows, and will profit from co-operative efforts between the Cancer Registry of Norway, University of Bergen, and international experts on cancer causes and control.