Niki Marjerrison

• Marjerrison, Niki; Grimsrud, Tom Kristian; Hansen, Johnni; Martinsen, Jan Ivar; Nordby, Karl-Christian & Olsen, Raymond [Show all 8 contributors for this article] (2023). Occupational exposures of firefighting and urinary tract cancer risk among men in the Norwegian Fire Departments Cohort. Occupational and Environmental Medicine. ISSN 1351-0711. 80(12). doi: 10.1136/oemed-2023-109003. Full text in Research Archive Show summary

  Objectives Increased risks of bladder cancer and mesothelioma were the strongest evidence for the recent reclassification of firefighting as carcinogenic (Group 1) by the International Agency for Research on Cancer. Our study aim was to develop indicators for specific firefighting exposures and examine associations with urinary tract cancer (UTC), including bladder cancer. Methods We developed indicators for exposure from employment at a fire department or in firefighting jobs, to fire and smoke, and to diesel exhaust for men in the Norwegian Fire Departments Cohort (n=4250). Incident UTC cases were obtained from the Cancer Registry of Norway (1960–2021). Poisson regression was used to estimate incidence rate ratios (IRR) with cumulative exposures grouped into tertiles (reference: lowest exposed tertile) with 0-year, 10-year and 15-year lagging of exposures. Results During 125 090 person-years of follow-up, there were 76 cases of UTC. IRRs were mostly non-significantly increased in the middle tertile and at or below 1 in the highest tertile for total duration of employment, number of fires attended and fire exposure score with and without lags. In the middle tertile for diesel exhaust exposure, UTC risk was elevated over twofold with 10-year (IRR 2.27, 95% CI 1.22 to 4.20) and 15- year (2.21, 1.18 to 4.16) lags, and near 1 in the highest tertile. Findings for bladder cancer were similar to those for UTC. Conclusions Dose-response associations between the exposure indicators and UTC were not observed. Future studies using the indicators with more cases are needed.

• Madar, Ahmed Ali; Kurniasari, Astrid; Marjerrison, Niki & Mdala, Ibrahimu (2023). Breastfeeding and Sleeping Patterns Among 6–12-Month-Old Infants in Norway. Maternal and Child Health Journal. ISSN 1092-7875. doi: 10.1007/s10995-023-03805-2.
• Sritharan, Jeavana; Kirkham, Tracy L.; MacLeod, Jill; Marjerrison, Niki; Lau, Ashley & Dakouo, Mamadou [Show all 10 contributors for this article] (2022). Cancer risk among firefighters and police in the Ontario workforce. Occupational and Environmental Medicine. ISSN 1351-0711. 79(8), p. 533–539. doi: 10.1136/oemed-2021-108146.
• Marjerrison, Niki; Jacobsen, Jarle; Demers, Paul A.; Grimsrud, Tom Kristian; Hansen, Johnni & Martinsen, Jan Ivar [Show all 9 contributors for this article] (2022). Comparison of cancer incidence and mortality in the Norwegian Fire Departments Cohort, 1960-2018. Occupational and Environmental Medicine. ISSN 1351-0711. 79, p. 736–743. doi: 10.1136/oemed-2022-108331. Full text in Research Archive Show summary

  Objectives Elevated risk of cancer at several sites has been reported among firefighters, although with mixed findings. The purpose of this study was to calculate standardised incidence ratios (SIRs) and standardised mortality ratios (SMRs) for cancer and compare them to assess whether use of the different measures could be a source of inconsistencies in findings. Methods The Norwegian Fire Departments Cohort, comprising 4295 male employees who worked at 15 fire departments across Norway, was linked to health outcome registries for the period 1960–2018. SIRs and SMRs were derived using national reference rates. Results Overall, we observed elevated incidence of colon cancer (SIR, 95% CI 1.27, 1.01 to 1.58), mesothelioma (2.59, 1.12 to 5.11), prostate cancer (1.18, 1.03 to 1.34) and all sites combined (1.15, 1.08 to 1.23). Smaller, non-significant elevations were found for mortality of colon cancer (SMR, 95% CI 1.20, 0.84 to 1.67) and mesothelioma (1.66, 0.34 to 4.86), while SMR for prostate cancer was at unity. Potential errors were observed in some of the mortality data, notably for mesothelioma cases. Among those who died of cancer, 3.7% (n=14) did not have a prior diagnosis of malignancy at the same site group. Conclusions Assessment of incidence or mortality did not greatly influence the interpretation of results. The most prominent differences in SIR and SMR appeared to be due to inconsistencies between sites of cancer diagnosis and cause of death. The difference in SIR and SMR for prostate cancer suggested a detection bias from differential screening practices.

• Marjerrison, Niki; Jakobsen, Jarle; Grimsrud, Tom Kristian; Hansen, Johnni; Martinsen, Jan Ivar & Nordby, Karl-Christian [Show all 8 contributors for this article] (2022). Cancer incidence in sites potentially related to occupational exposures: 58 years of follow-up of firefighters in the Norwegian Fire Departments Cohort. Scandinavian Journal of Work, Environment and Health. ISSN 0355-3140. 48(3), p. 210–219. doi: 10.5271/sjweh.4009. Full text in Research Archive Show summary

  Objectives Firefighters are exposed to a variety of known and suspected carcinogens through their work. However, the association with cancer risk has limited evidence. We examined cancer incidence among firefighters in the newly established Norwegian Fire Departments Cohort restricted to sites with established associations with carcinogens encountered during firefighting. This included sites within the respiratory, urinary, and lympho-hematopoietic systems, and the skin and all sites combined. Methods Male firefighters (N=3881) in the cohort were linked to the Cancer Registry of Norway for incident cancer cases occurring during the period 1960–2018. We calculated standardized incidence ratios (SIR) with rates for the national male population as reference, and stratified SIR analyses by period of first employment, duration of employment, and time since first employment. Results Elevated risk was seen for all sites combined (SIR 1.15, 95% confidence interval 1.07–1.23). Elevated risk of urinary tract cancer was observed among firefighters who began working before 1950, and with observation ≥40 years since first employment. Risk of mesothelioma and laryngeal cancer were elevated with ≥40 years since first employment and with ≥30 years employment duration. Conclusions The observed associations between firefighting and urinary tract cancer, laryngeal cancer, and mesothelioma have been observed in some studies previously, and our results suggest the observed elevated risks are related to carcinogenic occupational exposures. Differences in risk by period of employment potentially reflect changes in exposures from improved quality and use of personal protective equipment.

• Ahmed , Hassan Soheir; Marjerrison, Niki; Kjøllesdal, Marte Karoline Råberg; Stigum, Hein; Htet, Aung Soe & Bjertness, Espen [Show all 8 contributors for this article] (2019). Comparison of Cardiovascular Risk Factors among Somalis Living in Norway and Somaliland. International Journal of Environmental Research and Public Health (IJERPH). ISSN 1661-7827. 16(13), p. 1–12. doi: 10.3390/ijerph16132353. Full text in Research Archive
• Ahmed, Soheir H.; Meyer, Haakon E; Kjøllesdal, Marte Karoline Råberg; Marjerrison, Niki; Mdala, Ibrahimu & Htet, Aung Soe [Show all 8 contributors for this article] (2019). The prevalence of selected risk factors for non-communicable diseases in Hargeisa, Somaliland: a cross-sectional study. BMC Public Health. ISSN 1471-2458. 19(1). doi: 10.1186/s12889-019-7101-x. Full text in Research Archive

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• Færevik, Hilde; Sandsund, Mariann; Marjerrison, Niki; Li, Tian & Olsen, Raymond (2023). Webinar: The HERO project - Health risks and health effects of firefighter work . Show summary

  The project will study cancer incidence using register data and exposure estimates, and describe penetration of toxic smoke particles, gases and vapours in small-scale scenarios and in real fire scenarios. In addition, thermoregulatory responses in male and female firefighters will be studied. This will form the basis for development of measures to be used by manufacturers to improve their products related to protection of firefighters, changes in practice and supplementary knowledge that can lead to a reduction in the incidence of cancer among firefighters and more effective coordination between public agencies and fire safety actors. Health and occupational research groups at SINTEF, National Institute of Occupational Health (STAMI), the Cancer Registry of Norway (CRN) and RISE Fire Research will collaborate to generate knowledge about these topics. The project also collaborates with the Fire Research and Innovation Centre – FRIC, as well as an international advisory expert group and a reference group of representatives from firefighter departments, authorities, scientists and producers of firefighter clothing. Hot environmental conditions and high work intensity expose firefighters to significant levels of thermoregulatory stress. Also, many known and suspected carcinogenic substances have been demonstrated during knock down and overhaul of fires. In addition to direct exposure during firefighting, the personal protective equipment and gears may be an important source of hazardous exposures. An increased demand for new knowledge and a better understanding of factors leading to health problems/illnesses among firefighters is needed.

• Færevik, Hilde; Olsen, Raymond & Marjerrison, Niki (2023). Brannkonstablers helse - en stor samfunnsutfordring? Paneldebatt. Show summary

  «Det store brannløftet» var en gave fra Gjensidigestiftelsen til det norske samfunn på 350 millioner kroner. Prosjektet omfatter ulike tiltak som på kort og lang sikt vil trygge hverdagen til befolkningen ytterligere. En del av gaven anvendes på forskning. Konferansen formidlet viktig kunnskap fra denne forskningen, og ønsker å skape debatt og dialog om hva som er viktig å fokusere på innen brannforskning fremover. VI presenterte prosjektet HERO - helserisiko og helseforebygging hos brannkonstabler

• Marjerrison, Niki (2022). WP1: Exposure-related cancer risk among Norwegian firefighters.
• Marjerrison, Niki (2022). Eksponeringsrelatert kreftrisiko blant brannmenn.
• Marjerrison, Niki (2022). Cancer risk among Norwegian firefighters.
• Marjerrison, Niki (2022). Branncast - Brannmenn mot kreft Podcast serie.
• Marjerrison, Niki (2022). Aktuelt, Kreftforeningen "Kamp mot flammene gir økt kreftrisiko".
• Marjerrison, Niki (2022). Cancer risk among firefighters.
• Marjerrison, Niki (2022). AP1: Kreftrisiko blant brannmenn.
• Marjerrison, Niki (2022). Cancer incidence in sites potentially related to occupational exposures: 58 years of follow-up of firefighters in the Norwegian Fire Departments Cohort.
• Marjerrison, Niki; Jakobsen, Jarle; Grimsrud, Tom Kristian; Hansen, Johnnie; Martinsen, Jan Ivar & Nordby, Karl-Christian [Show all 8 contributors for this article] (2022). Cancer incidence and mortality in the Norwegian Fire Departments Cohort, 1960-2018.
• Marjerrison, Niki; Grimsrud, Tom Kristian; Hansen, Johnnie; Martinsen, Jan Ivar; Nordby, Karl-Christian & Veierød, Marit Bragelien [Show all 7 contributors for this article] (2022). Cancer incidence and mortality in the Norwegian Fire Departments cohort: Are incidence versus mortality outcome measures contributing to variability in risk estimates?
• Færevik, Hilde; Renberg, Julie; Sandsund, Mariann; Marjerrison, Niki & Kjærheim, Kristina (2022). Health effects and health risk of firefighting.
• Færevik, Hilde; Sandsund, Mariann; Renberg, Julie; Li, Tian; Marjerrison, Niki & Kjærheim, Kristina [Show all 7 contributors for this article] (2022). HERO - Helserisiko og helseeffekter av brannslukking - resultater fra arbeidspakkene.

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