{"url":"https://whatshealthyandwhy.com/power-lines-and-magnetic-fields/power-lines-and-childhood-leukemia","path":"/power-lines-and-magnetic-fields/power-lines-and-childhood-leukemia","alternates":{"json":"https://whatshealthyandwhy.com/api/articles/power-lines-and-magnetic-fields/power-lines-and-childhood-leukemia.json","markdown":"https://whatshealthyandwhy.com/power-lines-and-magnetic-fields/power-lines-and-childhood-leukemia.md"},"topic":{"slug":"power-lines-and-magnetic-fields","name":"Power Lines and Magnetic Fields","url":"https://whatshealthyandwhy.com/power-lines-and-magnetic-fields"},"slug":"power-lines-and-childhood-leukemia","order":1,"title":"Power Lines, Magnetic Fields, and Childhood Leukemia","question":"Do power lines and household magnetic fields raise childhood leukemia risk?","answer":"May, at rare high exposures: older pooled studies found about double the risk above 0.4 µT, a 2022 analysis found none, and cause is unproven.","description":"Do power lines and household magnetic fields raise childhood leukemia risk? Older pooled studies said yes at high exposures; the newest ones mostly do not.","confidence":2,"confidenceNote":"Large pooled datasets disagree: older ones suggest about double the risk at rare high exposures, a 2022 pooling found none, and no mechanism has been shown.","evidenceSummary":{"rctCount":0,"observationalCount":3,"metaAnalysisCount":6,"totalParticipants":"97,000+ in the largest pooled analysis","replicated":false,"newestStudyYear":2023},"category":{"categoryTitle":"What's Harming You","categorySlug":"harming-you","subcategoryName":"Environmental Toxins","subcategorySlug":"environment","url":"https://whatshealthyandwhy.com/explore/harming-you/environment"},"actions":["Skip costly fixes for a nearby power line: living within 50 m of a 200+ kV line gave a small, imprecise risk rise that magnetic fields did not explain [3].","Pre-warm the bed with an electric blanket, then switch it off before sleep. It is a free precaution resting on thin evidence [7][9]."],"cautions":["Even if fields were a cause, they would explain only a small share of cases (an estimated 3% in the US, with a range from -2% to 8%) [6].","A child with persistent unexplained symptoms, such as repeated fevers, unusual bruising or bone pain, needs a doctor whatever the suspected cause."],"simpleText":"May, at rare high exposures. In older pooled analyses, children whose homes averaged 0.4 microtesla (µT) or more had about twice the leukemia risk, but that was under 1% of children [1]. The most recent pooled analysis of individual data found no increase [2]. Living near power lines shows only a small, uncertain rise that magnetic fields do not explain [3], and lab and animal research gives little support [4].","mediumText":"How it works\n\nPower lines, house wiring and appliances give off extremely low-frequency (ELF) magnetic fields. These are not the radio waves of phones and Wi-Fi, which behave differently; for those see What the Science Says. Field strength is measured in microtesla (µT).\n\nWhat counts as high? Surveys of long-term average fields away from appliances put typical homes at 0.06 to 0.07 µT in the United States and about 0.04 µT in the UK [5]. The pooled studies saw their signal only at 0.3 to 0.4 µT or more [1][6]. That is rare: only 0.8% of children lived in homes at 0.4 µT or above [1]. Fields are stronger right beside some appliances. Electric blankets and electrically heated water beds, for example, measured about 0.45 and 0.20 µT at 10 cm [7].\n\nWhere the worry came from. Pooled data from before 2000 found risk near the no-effect level below 0.4 µT and about double at higher levels [1], with an odds ratio of 1.7 above 0.3 µT in a second pooling [6]. On that basis the International Agency for Research on Cancer (IARC) rated ELF magnetic fields \"possibly carcinogenic\" (Group 2B), yet evidence in animals is inadequate and mechanistic support is weak [4].\n\nWhy scientists doubt it. The effect has faded. A pooled analysis of newer studies found no increased risk [2]. A British study of power-line distance found the early excess risk shrank across the decades, which points to changing populations living near lines rather than a physical effect of the lines [8]. A 2023 meta-analysis still found higher risk above 0.4 µT, and also linked electric blankets to higher odds, though from only four studies [9].\n\nIf it were real. Even if the link were causal, modelling put the share of childhood leukemia attributable to fields at about 3% in the US (range -2% to 8%) [6] and up to 2% in Europe [4].\n\nWhat to do. Nothing drastic. The one cheap precaution with any support is to warm the bed with an electric blanket and switch it off before sleeping. The blanket evidence is thin, but the step costs nothing.","deepText":"The evidence in detail\n\nThe early pooled analyses. Ahlbom and colleagues combined nine studies with measured or calculated fields. Among 3,203 children with leukemia and 10,338 controls at under 0.4 µT, risk sat near the no-effect level. Among 44 children with leukemia and 62 controls at 0.4 µT or more, the summary relative risk was 2.00 (95% CI 1.27 to 3.13), found in 0.8% of children. The authors noted selection bias may explain part of it [1]. Greenland and colleagues pooled 12 studies with magnetic-field measures: little or no association at 0.1 to 0.3 µT, then an odds ratio of 1.7 (1.2 to 2.3) above 0.3 µT versus below 0.1 µT. Wire codes, a proxy based on the look of nearby wiring, behaved less consistently, and the wire-code link was not explained by measured fields [6].\n\nLarge null and weakening results. The US National Cancer Institute study measured fields for 24 hours in the bedrooms of 638 children with acute lymphoblastic leukemia and 620 controls. The odds ratio at 0.2 µT or more versus under 0.065 µT was 1.24 (0.86 to 1.79), and 0.88 (0.48 to 1.63) for the highest wire-code category [10]. A pooled analysis of seven studies published after 2000 (10,865 cases, 12,853 controls) gave odds ratios of 1.07, 1.16 and 1.44 (0.88 to 2.36) for 0.1 to 0.2, 0.2 to 0.3 and 0.3 µT or more, so the association was weaker and imprecise [11]. Amoon and colleagues pooled four recent studies (24,994 cases, 30,769 controls) and found an odds ratio of 1.01 for 0.4 µT or more, with risk declining over time. They said this could reflect methods, chance or a true \"disappearing effect\". Combining the three pooled analyses gave 1.45 (0.95 to 2.20) [2].\n\nMeta-analysis. Brabant and colleagues' 2023 review included 38 studies. Across 21 studies the pooled odds ratio was 1.26 (1.06 to 1.49), driven by studies before 2000 (1.51) rather than later ones (1.04). Twelve measurement studies gave 1.37 (1.05 to 1.80) above 0.4 µT, and 1.88 (1.31 to 2.70) for acute lymphoblastic leukemia alone, with nothing at lower fields. Living within 50 m of a line gave 1.11 (0.81 to 1.52). Electric blankets (four studies) gave 2.75 (1.71 to 4.42) and electric clocks 1.27 (1.01 to 1.60). The authors concluded that fields above 0.4 µT can raise risk [9]. The blanket and clock findings rest on very few studies.\n\nDistance from power lines. In a British registry study of 29,081 children with cancer, 9,700 of them with leukemia, Draper and colleagues found a relative risk of 1.69 (1.13 to 2.53) within 200 m of a high-voltage line at birth, and 1.23 (1.02 to 1.49) at 200 to 600 m. They noted there is no accepted biological mechanism and that chance or confounding was possible [12]. Bunch and colleagues extended the work to 53,515 children up to 2008. For 0 to 199 m versus over 1,000 m the relative risk was 4.50 (0.97 to 20.83) in the 1960s, 0.71 (0.49 to 1.03) in the 2000s and 1.12 (0.90 to 1.38) overall. A risk that declines over time is unlikely to come from a physical effect of the lines, the authors said, and more likely reflects changing populations near them [8]. An international pooled analysis of 11 record-based studies (29,049 cases, 68,231 controls) found no material association with distance. Within 50 m of lines of 200 kV or more the odds ratio was 1.33 (0.92 to 1.93), and there was no association with calculated magnetic fields [3].\n\nMechanism and risk assessment. The ARIMMORA consortium's assessment found limited human evidence, inadequate animal evidence and weak mechanistic support, with no direct DNA damage seen. New mouse-model findings pointed to possible mechanisms but need more data. If the association is causal, up to 2% of European childhood leukemias could be attributable [4].\n\nWhat cannot be resolved. The older data and the newer data disagree, and the reasons could be methods, chance or a real change in who lives near power lines. The measured-field and distance findings do not line up, which argues against fields as the explanation for proximity. All the evidence is observational, because a randomised trial of a rare childhood cancer is not practical.\n\nBottom line (confidence 2). Pre-2000 pooled data point to a risk roughly 1.7 to 2 times higher at the rarest, highest home exposures, but the 2022 pooling does not repeat it, power-line proximity is not explained by fields, and no mechanism supports it. Whether a small effect exists is unresolved. For most families, ordinary home and power-line exposures have not been shown to matter.","deepTruncated":false,"references":[{"id":"1","title":"A pooled analysis of magnetic fields and childhood leukaemia.","authors":"Ahlbom A, Day N, Feychting M, et al.","year":2000,"journal":"Br J Cancer","pmid":"10944614","url":"https://pubmed.ncbi.nlm.nih.gov/10944614/"},{"id":"2","title":"Pooled analysis of recent studies of magnetic fields and childhood leukemia.","authors":"Amoon AT, Swanson J, Magnani C, et al.","year":2022,"journal":"Environ Res","pmid":"34481821","url":"https://pubmed.ncbi.nlm.nih.gov/34481821/"},{"id":"3","title":"Proximity to overhead power lines and childhood leukaemia: an international pooled analysis.","authors":"Amoon AT, Crespi CM, Ahlbom A, et al.","year":2018,"journal":"Br J Cancer","pmid":"29808013","url":"https://pubmed.ncbi.nlm.nih.gov/29808013/"},{"id":"4","title":"Extremely low-frequency magnetic fields and risk of childhood leukemia: A risk assessment by the ARIMMORA consortium.","authors":"Schüz J, Dasenbrock C, Ravazzani P, et al.","year":2016,"journal":"Bioelectromagnetics","pmid":"26991812","url":"https://pubmed.ncbi.nlm.nih.gov/26991812/"},{"id":"5","title":"Comparison of residential power-frequency magnetic fields away from appliances in different countries.","authors":"Swanson J, Kaune WT","year":1999,"journal":"Bioelectromagnetics","pmid":"10230938","url":"https://pubmed.ncbi.nlm.nih.gov/10230938/"},{"id":"6","title":"A pooled analysis of magnetic fields, wire codes, and childhood leukemia. Childhood Leukemia-EMF Study Group.","authors":"Greenland S, Sheppard AR, Kaune WT, et al.","year":2000,"journal":"Epidemiology","pmid":"11055621","url":"https://pubmed.ncbi.nlm.nih.gov/11055621/"},{"id":"7","title":"Magnetic field characteristics of electric bed-heating devices.","authors":"Wilson BW, Lee GM, Yost MG, et al.","year":1996,"journal":"Bioelectromagnetics","pmid":"8809356","url":"https://pubmed.ncbi.nlm.nih.gov/8809356/"},{"id":"8","title":"Residential distance at birth from overhead high-voltage powerlines: childhood cancer risk in Britain 1962-2008.","authors":"Bunch KJ, Keegan TJ, Swanson J, et al.","year":2014,"journal":"Br J Cancer","pmid":"24504371","url":"https://pubmed.ncbi.nlm.nih.gov/24504371/"},{"id":"9","title":"Exposure to magnetic fields and childhood leukemia: a systematic review and meta-analysis of case-control and cohort studies.","authors":"Brabant C, Geerinck A, Beaudart C, et al.","year":2023,"journal":"Rev Environ Health","pmid":"35302721","url":"https://pubmed.ncbi.nlm.nih.gov/35302721/"},{"id":"10","title":"Residential exposure to magnetic fields and acute lymphoblastic leukemia in children.","authors":"Linet MS, Hatch EE, Kleinerman RA, et al.","year":1997,"journal":"N Engl J Med","pmid":"9203424","url":"https://pubmed.ncbi.nlm.nih.gov/9203424/"},{"id":"11","title":"Pooled analysis of recent studies on magnetic fields and childhood leukaemia.","authors":"Kheifets L, Ahlbom A, Crespi CM, et al.","year":2010,"journal":"Br J Cancer","pmid":"20877339","url":"https://pubmed.ncbi.nlm.nih.gov/20877339/"},{"id":"12","title":"Childhood cancer in relation to distance from high voltage power lines in England and Wales: a case-control study.","authors":"Draper G, Vincent T, Kroll ME, et al.","year":2005,"journal":"BMJ","pmid":"15933351","url":"https://pubmed.ncbi.nlm.nih.gov/15933351/"}],"wordCount":1185,"source":{"path":"src/content/topics/power-lines-and-magnetic-fields/power-lines-and-childhood-leukemia.md"},"citeAs":"“Do power lines and household magnetic fields raise childhood leukemia risk?.” What's Healthy and Why. https://whatshealthyandwhy.com/power-lines-and-magnetic-fields/power-lines-and-childhood-leukemia","notice":"General information backed by peer-reviewed research, not medical advice."}