ANSES’s new expert appraisal aimed to analyze all the new scientific knowledge available on exposure to low-frequency electromagnetic fields and their possible biological and health effects. In order to better characterize the exposure of populations, particularly in relation to their places of residence, ANSES has also funded various measurement campaigns.
Better knowledge of exhibitions
Populations are exposed to multiple sources of electromagnetic fields, whether in the outdoor environment via power lines, transport, transformers, or in the indoor environment via household appliances. The numerous studies carried out since 2010 now provide a more precise view of the exposure to low-frequency electromagnetic fields to which populations are subjected.
They show, in particular, that the highest values in the outdoor environment are measured in particular under very high voltage power lines and in the immediate vicinity of the premises of transformers or electrical substations. Inside homes, high levels of magnetic fields can be produced by household appliances, but exposure to these appliances is very brief and very localized.
Limit the exposure of sensitive populations near a high-voltage line
In 2010, ANSES highlighted the convergence of epidemiological studies which showed an association between the occurrence of childhood leukemia and exposure to low-frequency magnetic fields at levels above 0.2 µT or 0.4 µT. In view of the new data, the Agency confirms the “limited” level of evidence associated with this long-term effect, even if studies published after 2010 found this association less frequently.
As part of this expert appraisal, ANSES funded a study to quantify the share of the French population, and more specifically children, exposed to such levels of fields emitted by a high voltage line. This study, conducted by a team from Inserm and the University Hospital of Caen, indicates that approximately 40,000 children under the age of 15 (0.35% of the population) are exposed in their homes to a magnetic field greater than 0. .4 µT, and approximately 8,000 children (0.18%) are educated in a school exposed to a magnetic field greater than 0.4 µT.
Considering all of these results, the Agency reiterates its recommendation to limit, as a precaution, the number of sensitive people exposed around high-voltage lines as well as exposure. As such, it recommends not to install or fit out new establishments welcoming vulnerable people (hospitals, schools, etc.) in the immediate vicinity of very high voltage lines, nor to install new lines above such establishments.
The Agency also emphasizes that the current regulations in France only regulate exposure levels near electricity transmission and distribution lines, by respecting an exposure limit value. The Agency therefore recommends extending this regulatory provision to all sources of electromagnetic fields exposing the general population.
Control occupational exposures
The levels of worker exposure to low-frequency magnetic fields vary greatly depending on the positions held. A study conducted jointly by the National Research and Safety Institute for the Prevention of Workplace Accidents and Occupational Diseases (INRS) and the Pension and Occupational Health Insurance Funds (Carsat) has shown that some professionals may be exposed to very high field levels, potentially higher than the exposure limit values (1,000 µT at 50 Hz), in special situations such as when using certain industrial machines.
Thus, ANSES reiterates the importance of enforcing the regulatory provisions on occupational health and reducing situations of overexposure, in particular by adapting workstations. In addition, the Agency recommends that manufacturers of industrial machines emitting low-frequency electromagnetic fields measure the exposure associated with the use of these devices and indicate it in the technical documentation provided to customers and users.
Furthermore, at high exposure levels that may be encountered in the workplace, experimental studies have demonstrated the possibility of biological effects (oxidative stress, genotoxic effects, effects on cell physiology). However, the Agency indicates that the epidemiological studies are too heterogeneous to establish a link between occupational exposure and the appearance of chronic pathologies, in particular neurodegenerative diseases and tumors of the nervous system. It appears necessary to continue research on the possible risk of pathologies associated with exposure to low-frequency magnetic fields. Furthermore, the Agency recommends that a forthcoming reassessment of the exposure limit values take into account the most recent scientific elements.
Finally, the Agency draws attention to cases of exposure of pregnant women at work. Indeed, it has been shown that in certain occupational exposure scenarios, the current density induced in the fetus may be higher than the limit values recommended for the general population. ANSES therefore recommends that women be better informed and made aware of the regulatory provisions for adapting their workstations when they are pregnant, in order to limit exposure of the fetus to low-frequency electromagnetic fields.