Residential magnetic fields and childhood leukemia: a meta-analysis.

Abstract

OBJECTIVES: This article uses meta-analysis methodology to examine the statistical consistency and importance of random variation among results of epidemiologic studies of residential magnetic field exposure and childhood leukemia. METHODS: A variety of meta-analytic statistical methods were applied to all available studies combined and on sub-groups of studies chosen by exposure characteristics. Sample sizes and fail-safe n's were calculated to determine the robustness of results and the potential role of publication bias. RESULTS: Most studies show elevated but not statistically significant odds ratios. Results for exposures assessed by wire codes, distance, and/or historically reconstructed fields are relatively consistent, homogeneous, and positive, while those for direct magnetic field measurements are consistent, homogeneous, and marginally protective. Several unpublished studies, or a single unpublished study with several hundred subjects, would be needed to nullify the observed data. CONCLUSIONS: The observed results identify a consistent risk that cannot be explained by random variation. The data supporting magnetic fields as the principal risk factor are suggestive but inconsistent. Additional studies using innovative designs that focus on highly exposed children offer the most hope of untangling this issue.

The effects of extremely low frequency magnetic fields on mutation induction in mice

“…Likewise, a meta-analysis in 1998 reported a weak elevated risk of leukaemia for children exposed to residential magnetic fields and a positive association between childhood leukaemia and calculated historic fields ≥0.2 μT (OR = 1.90, 95% CI: 1.07-3.39) (Wartenberg, 1998). However, Tynes and Haldorsen (1997) failed to reproduce such findings, presenting no association between childhood cancer, including leukaemia, and residences near power lines, based on calculations from power line distance and records of load.…”

“…In addition, a meta-analysis of childhood brain tumour studies has also indicated a non-statistically significant link when presenting risk estimates with multiple exposure assessment methods (Wartenberg, 1998). The majority of casecontrol studies however, have failed to provide evidence of a positive association when assessing exposure with a range of methods (Feychting & Ahlbom, 1993;Gurney et al, 1996;Tynes & Haldorsen, 1997;UK Childhood Cancer Study Investigators, 1999), meta-analysis (Mezei et al, 2008) or in conjunction with appliance use either directly by the child or the mother during gestation Preston-Martin et al, 1996).…”

Campos magnéticos de frequência extremamente baixa e efeitos na saúde: revisão da literatura

“…Most suggested increased risk associated to higher exposure, although, in general, 95% Confidence Intervals had null risk in� cluded 41,53,54,55,56,57 .…”

Human health effects of EMFs: The cost of doing nothing

“…Most subsequent studies have confirmed elevated risks of leukemia [4][5][6], and several meta-analyses have shown significantly elevated odds ratios (ORs) whether exposure was determined through use of wire codes or measured magnetic fields [7][8][9]. In addition there is evidence that leukemia is elevated in adults employed in occupations that involve elevated exposure to EMFs from electricity [10].…”