Childhood leukemia: electric and magnetic fields as possible risk factors.

Abstract

Numerous epidemiologic studies have reported associations between measures of power-line electric or magnetic fields (EMFs) and childhood leukemia. The basis for such associations remains unexplained. In children, acute lymphoblastic leukemia represents approximately three-quarters of all U.S. leukemia types. Some risk factors for childhood leukemia have been established, and others are suspected. Pathogenesis, as investigated in animal models, is consistent with the multistep model of acute leukemia development. Studies of carcinogenicity in animals, however, are overwhelmingly negative and do not support the hypothesis that EMF exposure is a significant risk factor for hematopoietic neoplasia. We may fail to observe effects from EMFs because, from a mechanistic perspective, the effects of EMFs on biology are very weak. Cells and organs function despite many sources of chemical "noise" (e.g., stochastic, temperature, concentration, mechanical, and electrical noise), which exceed the induced EMF "signal" by a large factor. However, the inability to detect EMF effects in bioassay systems may be caused by the choice made for "EMF exposure." "Contact currents" or "contact voltages" have been proposed as a novel exposure metric, because their magnitude is related to measured power-line magnetic fields. A contact current occurs when a person touches two conductive surfaces at different voltages. Modeled analyses support contact currents as a plausible metric because of correlations with residential magnetic fields and opportunity for exposure. The possible role of contact currents as an explanatory variable in the reported associations between EMFs and childhood leukemia will need to be clarified by further measurements, biophysical analyses, bioassay studies, and epidemiology.

Central nervous system tumours in children: Epidemiology and risk factors

“…In an effort to explain why the effects of EMF remain biologically weak in animal and cellular systems, it has recently been proposed that ''contact currents or voltages,'' generated when a person touches conductive surfaces at different voltages, may provide an alternative metric for investigating the potential adverse health effects of EMF [Brain et al, 2003]. The role of contact currents in relation to observed associations between EMF and childhood leukaemia is being further investigated.…”

Effects of Fifty-Hertz Electromagnetic Fields on Granulocytic Differentiation of ATRA-Treated Acute Promyelocytic Leukemia NB4 Cells

“…Considering the extensive evidence linking ELF-EMFs exposure to haematopoietic alterations [7, 8, 23, 24], we focused on the role of ELF-EMFs in the proliferation and differentiation of acute promyelocytic leukemia (APL) cells, a model not yet investigated. APL (FAB M3) is a type of acute myeloid leukemia (AML) [25] and accounts for 5% to 10% of all AML cases.…”

A Plausible Biological Mechanism by which Extremely Low-Frequency Electromagnetic Fields Increase the Risk of Childhood Leukemia

“…This would explain why exposure to ELF-EMFs increases the risk of leukemia in children but not in adults. Accordingly, although carcinogenicity experiments in rodents have been largely negative [62], recent experiments have shown an increased risk of leukemia in rodents exposed to ELF-EMFs from prenatal life [63,64]. Evidence or lack of carcinogenicity in rodents exposed to ELF-EMFs should however be interpreted cautiously, because rodents and humans may not respond equally to non-ionizing electromagnetic radiation.…”