Motor neuron disease risk and magnetic field exposures

Abstract

Motor neuron disease risk and magnetic field exposures Tom Sorahan, Linda Nichols. Motor neuron disease risk and magnetic field exposures. Occup Med (Lond). 2021 Dec 23; kqab180. doi: 10.1093/occmed/kqab180. Abstract Background: Many studies have investigated magnetic field exposure and the risks of motor neuron disease (MND). Meta-analyses have found positive associations but a causal relationship has not been established. Aims: To investigate the risks of MND and occupational exposure to magnetic fields in a large UK cohort. Methods: Mortality of 37 986 employees of the former Central Electricity Generating Board of England and Wales was investigated for the period 1987-2018. Employees were first employed in the period 1942-82 and were still in employment on the 1 November, 1987. Detailed calculations enabled estimates to be made of magnetic field exposures. Observed deaths were compared with expected numbers based on mortality rates for the general population of England and Wales and Poisson regression was used to calculate rate ratios (relative risks) for categories of lifetime, lagged (distant) and lugged (recent) magnetic field exposure. Results: Mortality from MND in the total cohort was similar to national rates (observed 69, expected 71.3, SMR 97, 95% CI 76-122). There were no statistically significant trends of risks increasing with lifetime, recent or distant magnetic field exposure, although positive associations were observed for some categories of recent exposure. Conclusions: The study did not find that the cohort had elevated risks of MND as a consequence of occupational lifetime exposure to magnetic fields, although a possible role for recent exposures could usefully be investigated in other datasets. Funding: This work was supported by the Energy Networks Association (ENA). [The Energy Networks Association is the industry body funded by UK gas and electricity transmission and distribution licence holders.] pubmed.ncbi.nlm.nih.gov

AI evidence extraction

Main findings

In the total cohort, MND mortality was similar to national rates (69 observed vs 71.3 expected; SMR 97, 95% CI 76–122). No statistically significant trends were found for increasing risk with lifetime, recent, or distant magnetic field exposure, although positive associations were observed for some categories of recent exposure.

Outcomes measured

• Motor neuron disease (MND) mortality

Limitations

• Outcome assessed as mortality (not incidence).
• Exposure characterized via calculated estimates; specific field characteristics (e.g., frequency) not stated in abstract.
• Positive associations noted only in some recent-exposure categories and were not described as statistically significant.

Suggested hubs

• occupational-exposure (0.9)
  Study evaluates occupational magnetic field exposure in a large electricity-industry cohort.

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        "duration": "lifetime, lagged (distant), and lugged (recent) exposure categories; mortality follow-up 1987–2018"
    },
    "population": "Employees of the former Central Electricity Generating Board of England and Wales (UK)",
    "sample_size": 37986,
    "outcomes": [
        "Motor neuron disease (MND) mortality"
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    "main_findings": "In the total cohort, MND mortality was similar to national rates (69 observed vs 71.3 expected; SMR 97, 95% CI 76–122). No statistically significant trends were found for increasing risk with lifetime, recent, or distant magnetic field exposure, although positive associations were observed for some categories of recent exposure.",
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    "limitations": [
        "Outcome assessed as mortality (not incidence).",
        "Exposure characterized via calculated estimates; specific field characteristics (e.g., frequency) not stated in abstract.",
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    "peer_reviewed_likely": "yes",
    "keywords": [
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