Background Exposure to extremely low frequency magnetic fields (ELF-MFs) and electric shocks is a common occupational risk factor in many workplaces. Recent investigations have highlighted a possible association between such exposures and lymphoma risk. This study was carried out to further explore the association between occupational exposure to ELF-MFs and electric shocks and risk of lymphoma in a large Nordic census-based cohort.
Methods We included cases of non-Hodgkin's lymphoma (NHL, n=68 978), chronic lymphocytic leukaemia (CLL, n=20 615) and multiple myeloma (MM, n=35 467) diagnosed between 1961 and 2005 in Finland, Iceland, Norway and Sweden. Cases were matched to five controls by year of birth, sex and country. Lifetime occupational ELF-MF and electric shock exposures were assigned to jobs reported in population censuses using job-exposure matrices. The risk of cancer was assessed based on cumulative exposure to ELF-MF and electric shocks. ORs with 95% CIs were estimated using logistic models adjusted for occupational co-exposures relevant to lymphomas.
Results Less than 7% of the cases experienced high levels of ELF-MF. We observed no increased risks among workers exposed to high levels of ELF-MF for NHL (OR: 0.93; CI 0.90 to 0.97), CLL (OR: 0.98; CI 0.92 to 1.05) or MM (OR: 0.96; CI 0.90 to 1.01).
Conclusion Our results do not provide support for an association between occupational exposure to ELF-MFs and electric shocks and lymphoma risk.
- electromagnetic fields
- radiation, nonionizing
- occupational health
Data availability statement
All data relevant to the study are included in the article or uploaded as supplementary information.
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Contributors MG, AH and RV planned the study. SH, EP and KK contributed to data collection. HJ prepared the first draft of the manuscript. RV is responsible for the overall content as the guarantor. All authors interpreted the data, critically revised the manuscript and approved of the final version to be published.
Funding This work was supported by Qom University of Medical Sciences (grant number:1096) and by ZonMw (grant number 85500026). MG is funded by a Miguel Servet II fellowship (CPII18/00018) awarded by the Spanish Institute of Health Carlos III. The authors acknowledge support from the Spanish Ministry of Science and Innovation and the State Research Agency through the “Centro de Excelencia Severo Ochoa 2019-2023” Program (CEX2018-000806-S), and support from the Generalitat de Catalunya through the CERCA Program. The Nordic Occupational Cancer (NOCCA) Study was funded by the Nordic Cancer Union.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
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