Residential exposure to electromagnetic fields and risk of amyotrophic lateral sclerosis (ALS): a dose-response meta-analysis

{
  "publication_year": 2021,
  "study_type": "meta_analysis",
  "exposure": {
    "band": "ELF",
    "source": "power lines",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": null
  },
  "population": "Residential populations assessed for ALS risk in included epidemiologic studies",
  "sample_size": null,
  "outcomes": [
    "Amyotrophic lateral sclerosis (ALS) risk/incidence"
  ],
  "main_findings": "This dose-response meta-analysis of six studies found little evidence of a positive association between residential magnetic field exposure (assessed by distance to overhead power lines and/or magnetic-field modelling) and ALS risk. The highest exposure categories suggested decreased risk for both distance-based and especially modelling-based estimates, but the estimates were imprecise. Dose-response analysis showed little association between distance from power lines and ALS and no evidence of a threshold.",
  "effect_direction": "no_effect",
  "limitations": [
    "Only six eligible studies were identified.",
    "Risk estimates for highest exposure categories were imprecise (wide confidence intervals).",
    "Data were too limited to conduct dose-response analysis for modelled magnetic field estimates.",
    "Insufficient data to perform stratified analyses; associations in subgroups or at very high exposure could not be ruled out."
  ],
  "evidence_strength": "high",
  "confidence": 0.78,
  "peer_reviewed_likely": "yes",
  "stance": "reassurance",
  "stance_confidence": 0.72,
  "summary": "This systematic review and dose-response meta-analysis evaluated whether residential magnetic field exposure is associated with ALS risk. Across six eligible studies using distance to overhead power lines and/or magnetic-field modelling, the analysis found little evidence of a positive association. Estimates in the highest exposure categories suggested decreased risk but were very imprecise, and limited data prevented more detailed dose-response and subgroup analyses.",
  "key_points": [
    "The paper reports a systematic review and dose-response meta-analysis of residential electromagnetic (magnetic) field exposure and ALS risk.",
    "Six studies met inclusion criteria, using distance from overhead power lines and/or magnetic-field modelling for exposure assessment.",
    "Highest exposure categories showed summary estimates below 1.0 for both distance-based and modelling-based exposure, but with wide confidence intervals.",
    "Dose-response analysis indicated little association between distance from power lines and ALS and no evidence of a threshold effect.",
    "The authors conclude there is scant evidence for a positive association between residential magnetic fields and ALS.",
    "Limited data prevented dose-response analysis for modelled exposure studies and stratified analyses.",
    "The authors note that associations in selected subgroups or at very high exposure cannot be entirely ruled out."
  ],
  "categories": [
    "Epidemiology",
    "Neurodegenerative Disease",
    "Power Lines",
    "Extremely Low Frequency (ELF)"
  ],
  "tags": [
    "Amyotrophic Lateral Sclerosis",
    "Dose-Response Meta-Analysis",
    "Systematic Review",
    "Residential Exposure",
    "Magnetic Fields",
    "Overhead Power Lines",
    "Distance-Based Exposure",
    "Magnetic Field Modelling",
    "Risk Ratio"
  ],
  "keywords": [
    "ALS",
    "amyotrophic lateral sclerosis",
    "residential exposure",
    "magnetic fields",
    "electromagnetic fields",
    "power lines",
    "distance",
    "modelling",
    "dose-response",
    "meta-analysis"
  ],
  "suggested_hubs": [
    {
      "slug": "power-lines",
      "weight": 0.95,
      "reason": "Exposure assessment focused on distance from high-voltage overhead power lines and magnetic-field modelling related to power lines."
    }
  ],
  "social": {
    "tweet": "Meta-analysis (6 studies) found little evidence that residential magnetic-field exposure (power-line distance/modelling) increases ALS risk; highest exposure categories suggested lower risk but estimates were imprecise and data limited.",
    "facebook": "A 2021 systematic review and dose-response meta-analysis of six studies reported little evidence of a positive association between residential magnetic-field exposure (including distance to overhead power lines) and ALS risk, though data were limited for detailed analyses.",
    "linkedin": "In a 2021 Sci Rep dose-response meta-analysis of six studies, residential magnetic-field exposure assessed via power-line distance and/or modelling showed little evidence of increased ALS risk; estimates at highest exposure were imprecise and limited data constrained subgroup analyses."
  }
}