Cancer risk among firefighters
Background & Purpose
The International Agency for Research on Cancer has this year made an assessment of cancer risk among firefighters. This profession is now classified as a carcinogen. That is, the exposure firefighters are exposed to in their jobs can contribute to the development of cancer. The conclusion is based on the findings made for mesothelioma and bladder cancer. A group of 25 international experts has evaluated the scientific literature on the topic and reached its conclusion. Project manager Kristina Kjærheim was one of the experts who contributed to the assessment, and articles from our PhD candidates, Jarl Jakobsen and Niki Marjerrison, were included in the material evaluated.
However, we still lack knowledge about the cause of such an elevated risk and how it can best be prevented.
The Cancer Registry of Norway and the National Institute of Occupational Health are working on a project to investigate this question among Norwegian firefighters. The project has two main objectives:
- To evaluate the association between occupational history and cancer risk among firefighters
- To evaluate the association between specific exposures and cancer risk
In the project, we have established a cohort of firefighters and other employees at selected Norwegian fire departments from 1960 onwards. In total, we have included approximately 4000 full-time firefighters and other employees from fifteen of the largest Norwegian cities/fire services.
For each person in the cohort, we have the name and date of birth, all positions/occupational titles of people who have worked at the fire department, including start and end dates for all employment periods. These personal data are linked to registrations from the Cancer Registry of Norway and the Cause of Death Registry. This means that we have an overview of everyone in the cohort who has received a cancer diagnosis, including the date of diagnosis and type of cancer, and everyone who has died, including date of death and cause of death. In this way, we can investigate both the incidence and mortality of cancer among firefighters and compare this with the rates in the general population.
The Directorate for Civil Protection and Emergency Planning (DSB) has provided us with an overview of the number and type of call-outs in the municipalities where the fire services are located. By considering this in the context of cancer incidence, we can investigate whether there is a correlation between the number of fires a firefighter has participated in and cancer risk.
From each of the participating fire departments, we have collected information on a wide range of working environment conditions from 1950 onwards. By adding this to the analyses, we can investigate the association between the use of respiratory protection or other protective measures and cancer risk. Information on the number of cars, type of fuel and station architecture allows us to study the association between exposure to diesel exhaust and cancer risk.
We have annual meetings with the scientific reference group for input and discussion about the project. Read more about the reference group meeting here.
The work is carried out in accordance with applicable Norwegian and international data protection regulations and with permission from the Regional Committee for Medical Research Ethics. Read more about privacy at the Cancer Registry.
The cohort has now been established, and two PhD fellows are employed and working on analysis and publication of articles.
Project 1: Cancer risk and exposures among firefighters
Niki Marjerrison started as a PhD candidate on the project on 2 January 2020. The overarching issue is whether there is a link between cancer risk and the exposures that firefighters are exposed to.
The first sub-project is an analysis of the risk of cancer diseases that has a known association with exposures that are known to occur during fire extinguishing. Previous research in the field has shown relatively inconsistent findings. Therefore, the second sub-project will consist of a study of whether this can partly be explained by the fact that some publications have studied the risk of receiving a cancer diagnosis, while in others the risk of dying from cancer has been analysed.
The last sub-project is planned as an analysis of the association between the risk of cancer of the urinary tract and indicators of occupational exposures. The focus will be particularly on exposure to PAHs (polycyclic hydrocarbons), which have a known association with bladder cancer.
Planned and completed publications:
Cancer incidence in sites potentially related to occupational exposures: 58 years of follow-up of firefighters in the Norwegian Fire Departments Cohort. Marjerrison N, Jakobsen J, Grimsrud TK, Hansen J, Martinsen JI, Nordby KC, Veierød MB, Kjærheim K. Scand J Work Environ Health. 2022 Apr 1;48(3):210-219. doi: 10.5271/sjweh.4009. Epub 2022 Jan 11. PMID: 35015085.
- Bladder cancer incidence and exposure to polycyclic aromatic hydrocarbons among firefighters in the Norwegian Fire Departments Cohort (NO: Bladder cancer and exposure to polycyclic aromatic hydrocarbons among firefighters in the Norwegian fire brigade cohort) Status: in progress Jan.2022.
Project 2: Prostate cancer among firefighters
Jarle Jakobsen started as a PhD candidate at the Cancer Registry of Norway on 11 February 2019. The background for the project is that the risk of prostate cancer has generally been elevated in studies of firefighters. However, it is unclear whether this is related to occupational exposures and, if so, which exposures.
The first part of the work consists of a description of the development of working environment conditions that have a possible impact on the exposure to carcinogenic influences from 1950 to 2015. It has been argued that the increased risk of prostate cancer among firefighters may be due to an increased incidence of health checks and testing for prostate-specific antigen (PSA). To elucidate the extent to which such a screening effect may have an impact, the second sub-project is an analysis of the characteristics of prostate cancer in firefighters compared with prostate cancer among policemen, pilots, military personnel and the rest of the population. Age at diagnosis, stage at diagnosis and mortality are among the variables included.
The final sub-project is an analysis of the relationship between prostate cancer risk and indicators for occupational exposures.
Planned and completed publications:
- Work conditions and practices in Norwegian fire departments from 1950 until today: A survey on factors potentially influencing carcinogen exposure. Jakobsen J, Babigumira R, Danielsen M, Grimsrud TK, Olsen R, Rosting C, Veierød MB, Kjærheim K.Saf Health Work. 2020 Dec;11(4):509-516. doi: 10.1016/j.shaw.2020.07.004. Epub 2020 Jul 18. PMID: 33329918
- Early detection of prostate cancer in firefighters: a register-based study of prognostic factors and survival. Jakobsen J, Veierød MB, Grimsrud TK, Fosså SD, Hammarström B, Kjærheim K.Occup Environ Med. 2021 Sep 11:OEMED-2021-107622. doi: 10.1136/oemed-2021-107622. Online ahead of print. PMID: 34510005
- Prostate cancer incidence and occupational exposure among firefighters in the Norwegian Fire Departments Cohort (....) Status: Work in progress Jan. 2022..