The Cancer Registry of Norway presents new studies on cancer risk among offshore workers

The Cancer Registry of Norway will continue its research on cancer risk among employees in the oil and gas industry – but first they must first know who has worked in the industry since the turn of the millennium. Helicopter transports to and from offshore installations are of key importance.
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The Troll A platform in the North Sea. Photo: Øyvind Knoph Askeland/Wikimedia


"We are very pleased that the Research Council of Norway and the oil and gas industry have allocated a total of NOK 7.5 million to new studies among offshore workers. We will use the funds to establish an overview of people who have worked offshore in recent times, in addition to new cancer studies," says researcher Tom K. Grimsrud at the Cancer Registry.

Read more about the study here

Together with researcher Jo S. Stenehjem, he will lead the new project called the "Heliport project".

The planned overview of offshore workers will form the basis for new studies of health risks associated with occupational exposure after 1998. This will increase awareness and knowledge about the petroleum industry's work on health, safety and the environment (HSE).

Jo Stenehjem, researcher

"For a long time, special attention has been paid to cancer risk in lymph, blood and lung associated with long-term benzene exposure. Studies of these cancers are based on occupational history from the period 1965 to 1998, and now we need new studies with occupational history from recent decades. This is one of the things we now want to study," says Stenehjem.

The researchers note that there is also a need for more knowledge about shift and night work, and whether this makes people more vulnerable to disease and injury from benzene exposure.

They also plan to involve a PhD candidate in the work.

"If someone has worked offshore in recent years and now wants to contribute to this research, what should they do?
- This project has two steps; In step 1, we will collect information about occupational history from helicopter transport databases, so the workers do not have to sign up themselves," says Stenehjem.

Closer to the summer, he hopes to start step 2, which is an online questionnaire survey, where everyone registered in helicopter transport databases receives an SMS with a link to an encrypted and secure questionnaire survey. However, such a survey is dependent on all formal permits and approvals being put in place, which is currently being worked on.

- Yes, we are now working towards this. And in order to get good and credible results, it will be very important that as many people as possible respond to the questionnaire survey, but those who are relevant will be contacted and do not need to take any action before they receive an inquiry from us, he says.

Helicopter transport will thus be central to obtaining an overview of employees. More on that soon, but first a little about what is already known about cancer risk among employees offshore.

Earlier studies among offshore workers

For several years, the Cancer Registry of Norway has studied offshore workers and risks related to their work situation. The previous studies are mainly based on data from 28,000 people who worked offshore in the industry's first decade. This data material has been named " The Offshore Cohort", and was established through a large survey conducted by the Cancer Registry of Norway in 1998.

"It is now more than 20 years since this survey was conducted, and we know that technology and jobs are constantly evolving. New and expanded knowledge emerges, and new HSE measures are implemented to safeguard employees' safety and health, and stable production. Nevertheless, we do not know whether the changes over the past 20 years have reduced the risk of disease," says Grimsrud.

The results of previous analyses conducted on the "Offshore Cohort" have shown an increased risk of some cancers among offshore workers compared to the general Norwegian population.

"In in-depth studies, we have seen that certain forms of lymphatic and blood cancer appear to increase in line with increasing benzene exposure. The risk of skin cancer on the arms from the elbow down seems to increase with the duration of skin contact with crude oil, which contains both PAH compounds and benzene, says researcher Jo S. Stenehjem.

Now the question is whether these results are equally relevant for today's offshore workers? Have there been new challenges that can lead to health problems among offshore workers? Has the incidence of new cases decreased in recent decades? And not least, have measures to protect workers had the intended effect, reducing the risk of chronic diseases?

Health risks in recent times?

As of today, there is no complete overview of who has worked offshore in the period after 1998. Such an overview is a necessary prerequisite for assessing health risks among those who worked offshore in the 2000s.

"Fortunately, there is a common interest in these issues, both among the companies themselves, among the trade unions and the supervisory authorities in order to study more closely what has happened since the turn of the century," says Stenehjem.

The same interest has also been expressed by the government several times.

"In the new project, we are collaborating with the industry to obtain a reliable overview of who has been offshore in recent decades by extracting data from helicopter transport to and from offshore installations," says Grimsrud.

As part of the offshore safety work in recent decades, all passenger transports by helicopter to and from the platforms have been logged with the companies.

The researchers hope that this can help to deal with the challenge of basically no systematic and complete overview of everyone who has worked offshore since the turn of the millennium.

Grimsrud goes on to say that the idea of using helicopter transport data is not really new. The proposal came from employees in the oil industry, both from the health and environmental sides and from the trade unions.

"By making this type of information available for research, we can contribute to new knowledge about health risks in different work situations, and perhaps we can also look at some of the effect of implemented working environment measures offshore.

Further research involves sensitive data, and will take place on de-identified data to safeguard the individual's need for privacy.

Will investigate both cancer and other health outcomes

The Heliport project is now in the start-up phase, and requires cooperation with nine operating companies and the Norwegian Shipowners' Association. As the project approaches the analysis phase, several academic partners will assist in choices and discussions of the results.

The project has been pre-approved by the Regional Committee for Medical and Health Research Ethics (REK), and a data protection impact assessment (mandatory under GDPR) is now being processed.

The next step will be to obtain data from helicopter transport and occupational history from the companies. If this succeeds, it is assumed that information will be obtained on up to 50,000 people who have been employed from 1981 until today.

In the future, the ambition is that the established overview can also be used to study other types of disease and injuries than cancer, by linking them to other national health registries.

These may include cardiovascular diseases, neurological diseases, musculoskeletal disorders and accidental injuries. However, such future studies of health outcomes other than cancer will depend on separate REK approvals.

Grimsrud and Stenehjem hope that the project will prove useful for all parties within the traditional tripartite cooperation – industry, trade unions and supervisory authorities.

"Here we have the opportunity to create a state-of-the-art tool for monitoring and effect evaluation of HSE in the petroleum activities, which will have great societal value for one of Norway's largest and most important industries," says Stenehjem.

"At the same time, it is crucial that the study is carefully planned and carried out with great discretion, so that we safeguard the privacy of each employee. We are very much looking forward to getting started, and look forward to working on this important project in the future, concludes an enthusiastic Grimsrud.