Exposure assessment and prevention of death, disease and injuries among offshoreworkers

Throughout the last decades, the petroleum industry on the Norwegian continental shelf has shown its excellence in the characterization and management of risk, avoidance of large-scale accidents with possible loss of lives, environmental damage and great economic costs.1 However, associations between occupational exposures and subsequent chronic disease and early death have not been possible to assess in the two last decades due to a paucity of comprehensive personnel lists with work history and exposure data after year 2000. The project is anchored at the University of Oslo (UiO), with the Cancer Registry of Norway as collaborating partner.
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Together with the University of Oslo (UiO), the Cancer Registry of Norway has conducted and is conducting a number of studies looking at cancer incidence among Norwegian offshore workers who had worked between 1965 and 1998 using the Cancer Registry's NOPW cohort from 1998. The NOPW cohort was linked to job exposure matrices, developed by occupational hygienists at the University of Bergen (UiB) to assess the exposure offshore workers had been exposed to. However, there is a lack of updated occupational history and exposure estimates after 1998.

In order to obtain updated data on occupational history after 1998, the Cancer Registry of Norway is now working to establish a cohort of offshore employees who work or have worked offshore since the 2000s. This cohort is based on helicopter transport to and from the platforms and is therefore called the Heliport cohort. You can read more about the data collection and the Heliport cohort here. The NOPW cohort will be joint with the new Heliport-cohort, this will provide a total overview of offshore workers from 1965 upon today.

UiB will develop updated occupational-exposure matrixes based on benzene, oil mist and oil vapor measurements from 2000 -2020.

The new combined cohort will be linked to other health registries to enable investigation of diseases, injuries and mortality among offshore workers.


The aim of this ongoing project is to fill the beforementioned knowledge gap by establishing a historic overview of Norwegian offshore workers that can provide an updated and reliable source on exposure related disease risk in the petroleum industry from its pioneer-days upon today. The aim of the project is threefold:

1) To use the newly collected data on benzene and oil mist/vapor in the petroleum industry to develop updated JEM’s for the 2000-2020 period. UiB and STAMI will focus on this workpackage

2) Conduct a questionnaire study in the Heliport-cohort, harmonizing the NOPW and Heliport-cohort and linking the NOPW/Heliport-cohort to other health registries. The Cancer Registry of Norway will focus on this workpackage.

3) Studies on mortality, morbidity and injuries after occupational exposure and lifestyle risk factors. UiO will focus on this workpackage. Specific questions to be answered are:

  • Is the mortality, total and cause of death, higher among petroleum workers than the general population?
  • Can cardiovascular, respiratory or neurological diseases (prevalence and mortality) be explained by high exposure to benzene and oil mist/vapor?
  • Can psychological illness and traumatic injuries (prevalence and mortality) be explained by shift-based work? By use of prescription drugs? By sleep deprivation, co-morbidity?
  • Is there an excess higher prescription of drugs among petroleum workers than the general population?
  • Can use of prescription drugs among offshore petroleum workers be explained by shift-based work? By sleep deprivation? By co-morbidity?

Reference group

The project has an active reference group consisting at all times of representatives from the employee, employer and supervisory authorities. The reference group consists of representatives from the Norwegian Confederation of Trade Unions, SAFE, the Federation of Norwegian Industries, the Petroleum Safety Authority, the Norwegian Shipowners' Association and Equinor.