Mar 17, 2016

Extremely low-frequency magnetic fields and the risk of childhood leukemia: A risk assessment by the ARIMMORA consortium

Joachim Schüz, Clemens Dasenbrock, Paolo Ravazzani, Martin Röösli, Primo Schär, Patricia L. Bounds, Friederike Erdmann, Arndt Borkhardt, César Cobaleda, Maren Fedrowitz, Yngve Hamnerius, Isidro Sanchez-Garcia, Rony Seger, Kjeld Schmiegelow, Gunde Ziegelberger, Myles Capstick, Melissa Manser, Meike Müller, Christoph D. Schmid, David Schürmann, Benjamin Struchen, and Niels Kuster, Bioelectromagnetics, Volume 37, Issue 3, pp. 183–189, April 2016, online March 15, 2016

Exposure to extremely low-frequency magnetic fields (ELF-MF), related to power transmission and the use of electrical appliances, has been classified since 2001 as possibly carcinogenic to humans (Group 2 B) according to the classification of the International Agency for Research on Cancer (IARC) Monograph program. The IT'IS Foundation led the European Commission-funded project “Advanced Research on Interaction Mechanisms of electroMagnetic exposures with Organisms for Risk Assessment” (ARIMMORA), in which a series of experiments targeted to find possible mechanistic pathways to explain the association between ELF-MF and childhood leukemia were conducted. The ARIMMORA consortium applied novel experimental and computational techniques to examine evidence — epidemiological, environmental, biological, and biochemical — supporting the association between residential exposure to ELF MF and childhood leukemia and to elucidate underlying biophysical mechanisms. The ARIMMORA project was concluded with a risk assessment conducted March 2015 in which the available scientific evidence published before the risk assessment, including new results from the ARIMMORA experiments, were considered. The paper summaries the risk assessment performed at the IARC headquarters in Lyon adopting the concept of the IARC monographs. 

The scientific, technical, and social impact of the findings of the ARIMMORA consortium reported in the publication can be summarized as:

  • A new transgenic mouse model for the study of human childhood precursor-B acute lymphoblastic leukemia (B-ALL) was successfully established and used in ELF-MF exposure studies; however, the sample size was too small for the results to be conclusive and needs to be repeated with higher numbers of animals
  • Small but statistically significant transient reductions in numbers of CD8+ cytotoxic T-lymphocytes were confirmed in three independent animal studies
  • In field studies it was shown that the typical daily mean personal exposure of children in Europe is below 0.1 µT, while only 1–2% of children are exposed to ELF-MF daily means >0.3 µT, the thresshold at which an association between ELF-MF and childhood leukemia risk is observed
  • New detailed exposure data based on simulations of pregnant woman and children models have been made available, and transformation rules that allow comparison of data from animal and human studies have been derived
  • The conclusions of the ARIMMORA risk assessment support continued IARC classification as Group 2B of ELF-MF exposure as possibly carcinogenic to humans