Study of the French population exposure to the 50 Hertz magnetic field

The magnetic fields (MF) at extremely low frequency (ELF) have been suspected, for around 30 years, to be responsible for several pathologies in humans, more precisely, childhood leukemia. The last collective assessment by international expert groups (WHO 2007, SCENHIR 2009) concluded that the last major questioning concerning ELF MF is the statistic correlation observed in several meta-analysis between the increase of childhood leukemia risk and a MF exposure higher than 0:4μT in means over 24 h (Ahlbom et al., 2000), without any causal relation. To study the exposure of the French population to 50 Hz MF, two representative samples of this population (1000 adults and 1000 children) were created using random selection method. Each volunteer wore an EMDEX II measuring and recording MF during 24-hour period and progressively completed a timetable and a questionnaire containing specific information about himself and his home. When returning the measurement device, the pollster noted GPS coordinates at the front door of volunteer home, in order to identify afterwards electric networks near the home. To characterize mean exposures, nonparametric regression models were applied. They have allowed identifying among the data collected, the factors favoring a higher mean exposure. Each series of MF was then described by indicators and hierarchical clustering was applied. Three classes of expo- sure were defined. A logistic regression was used to identify factors favoring probability of belonging to the most exposed classes. (author)