{
  "id": "studies:ahlbom-2000",
  "collection": "studies",
  "slug": "ahlbom-2000-pooled-childhood-leukaemia",
  "name": "Ahlbom et al. pooled analysis of magnetic fields and childhood leukaemia (2000)",
  "summary": "A pooled analysis of nine studies that produced the 0.3–0.4 µT figure still cited in every ELF policy discussion, reporting roughly twice the relative risk above that level.",
  "status": "verified",
  "lastVerified": "2026-08-12",
  "data": {
    "authors": "Ahlbom A, Day N, Feychting M, et al.",
    "year": 2000,
    "design": "systematic-review",
    "exposure": "Residential 50/60 Hz magnetic field, time-weighted average",
    "finding": "No excess risk below 0.4 µT; a relative risk of about 2.0 for exposures at or above 0.4 µT, consistent across the pooled datasets.",
    "limitations": "Very few children were in the highest exposure category, so the estimate is statistically fragile. Possible selection bias in participation, and no mechanistic explanation. Pooling reduces random error but not shared systematic error.",
    "weight": "high",
    "url": "https://pubmed.ncbi.nlm.nih.gov/10970686/",
    "related": [
      "studies:iarc-elf-2b-2002",
      "limits:who-elf-leukaemia-association"
    ]
  },
  "sources": [
    {
      "id": "ahlbom-2000",
      "title": "A pooled analysis of magnetic fields and childhood leukaemia",
      "publisher": "British Journal of Cancer",
      "url": "https://pubmed.ncbi.nlm.nih.gov/10970686/",
      "year": 2000,
      "kind": "peer-reviewed",
      "retrieved": "2026-08-12"
    },
    {
      "id": "who-elf",
      "title": "Electromagnetic fields and public health: exposure to extremely low frequency fields",
      "publisher": "World Health Organization",
      "url": "https://www.who.int/teams/environment-climate-change-and-health/radiation-and-health/non-ionizing/exposure",
      "year": 2007,
      "kind": "government",
      "retrieved": "2026-08-12"
    }
  ],
  "links": {
    "self": "https://emfbase.com/api/studies/ahlbom-2000-pooled-childhood-leukaemia",
    "html": "https://emfbase.com/studies/ahlbom-2000-pooled-childhood-leukaemia",
    "markdown": "https://emfbase.com/studies/ahlbom-2000-pooled-childhood-leukaemia.md",
    "collection": "https://emfbase.com/api/studies"
  }
}