Cancer risk after benzene exposure

There are several ongoing research sub-projects at the Cancer Registry of Norway (CRN) that investigate cancer risk among offshore workers. This particular project looks into the relation between recent offshore benzene exposure and the risk to develop different cancers.

Last updated: 8/15/2024

Background

In recent years, there has been increased awareness of benzene exposure and the associated risk of cancer. Research suggests that benzene has a carcinogenic effect at lower concentrations than first thought, and that benzene exposure may be linked to several types of cancer, such as lymphomas and leukaemia. Our studies on this topic used data from the “Offshore-cohort” from 1998, which include offshore workers active between 1965 and 1998. For evaluation of more recent exposures, which may be lower than those of the 1980s–1990s, there is a need for new data from the last 20 years of offshore activity.

Aims

This study will use data from the new “heliport-cohort” to study benzene exposure and the risk of cancer among offshore workers in recent years. The first scientific questions are:

Does benzene exposure measured as a time-dependent variable and occurring at low levels increase the risk of lymphomas, leukaemia, and related cancers?

Does benzene exposure measure as a time-dependent variable lead to increased lung cancer risk when smoking habits are adjusted for?

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Project status and Main Results

• In December 2019, the Cancer Registry of Norway was awarded an industry collaborative grant of 7.5 million NOK from the Research Council of Norway’s PETROMAKS2 program (project no. 308846) with support from9 Norwegian oil and gas operating companies and the Norwegian Shipowners Association.

• In 2020-2021, all necessary paperwork was completed, including Collaboration Agreements, ethical approval (REK), and a Data Protection Impact Assessment (DPIA).

• In 2021, we initiated the establishment of the Heliport cohort based on helicopter transport records, and in 2022-2023 an additional survey was distributed to offshore workers.

• In 2024-2025, we are performing data cleaning and harmonization of the Heliport cohort.

Scientific findings:

Benzene and lung cancer:

In offshore petroleum workers, who were generally exposed to low levels of benzene, an association was suggested for the duration of benzene exposure and adenocarcinoma, the largest histological subgroup of lung cancer. The weak evidence we found might be due to the relatively small number of cases, which might have limited our ability to detect a clear association for all lung cancer types combined.

In the media

The research project has gotten the following media attention (all in Norwegian):

Ny kreftlink oppdaget: - ikke overrasket - Stavanger Aftenblad

Nye studier om kreftrisiko blant offshorearbeidere

Jakter på oljearbeiderne - nrk.no

Kreftrisikoen blant offshorearbeidere skal kartlegges - forskning.no

Referencegroup

The project has an active reference group which consist of representatives from the employee, employer and supervisory authorities. As of November 2020, the reference group consists of representatives from LO, SAFE, Norsk Industri, Petroleumstilsynet, Norges Rederiforbund and Equinor.