International Journal of
Environmental Research and Public Health Article
Children’s Personal Exposure Measurements to Extremely Low Frequency Magnetic Fields in Italy Ilaria Liorni 1, *, Marta Parazzini 1 , Benjamin Struchen 2,3 , Serena Fiocchi 1 , Martin Röösli 2,3 and Paolo Ravazzani 1 1
2 3
*
CNR Consiglio Nazionale delle Ricerche, Istituto di Elettronica e di Ingegneria dell’Informazione e delle Telecomunicazioni IEIIT, Piazza Leonardo da Vinci, Milano 20133, Italy; [email protected] (M.P.); [email protected] (S.F.); [email protected] (P.R.) Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel 4002, Switzerland; [email protected] (B.S.); [email protected] (M.R.) University of Basel, Basel 4003, Switzerland Correspondence: [email protected]; Tel.: +39-02-2399-3395
Academic Editor: Irena Cosic Received: 3 March 2016; Accepted: 26 May 2016; Published: 31 May 2016
Abstract: Extremely low frequency magnetic fields (ELF-MFs) exposure is still a topic of concern due to their possible impact on children’s health. Although epidemiological studies claimed an evidence of a possible association between ELF-MF above 0.4 µT and childhood leukemia, biological mechanisms able to support a causal relationship between ELF-MF and this disease were not found yet. To provide further knowledge about children’s ELF-MF exposure correlated to children’s daily activities, a measurement study was conducted in Milan (Italy). Eighty-six children were recruited, 52 of whom were specifically chosen with respect to the distance to power lines and built-in transformers to oversample potentially highly exposed children. Personal and bedroom measurements were performed for each child in two different seasons. The major outcomes of this study are: (1) median values over 24-h personal and bedroom measurements were 0.001; *** calculated p ď 0.001). Reference for “study group”: reference “season”: On average, it was that children are used to OTHER; spending 42% offorthe day at summer; home during reference for “measurement type”: bedroom. the night, 28% during the day, 18% of the daily time at school, and 10% outdoors. The remaining time of about 2% was indicated by parents as time spent indoors in a place different from home; however, Innot general, children the PL In and OTHERchildren groups spent are always it was considered in within this analysis. general, more more time exposed at home than in thechildren winter belonging to TRANSF group, as previously observed above. Seasonal variations have no significant period than in summer (+4%), while in the summer children spent more time outdoors than in the effect on exposure, as well as measurement type apart from a significant difference in the arithmetic winter (+3%). meanFigure of personal andsimilar bedroom measurements, in measures the formerofshowing an, onfield average, around 6 shows distributions for allresulting summary the magnetic in the same 30% higher exposure. environment for each group and in both seasons. For this reason the results are discussed only in children’s were value. analyzed over each 24-h period, an analysis of the personal termsOnce of the trend of measurements the geometric mean measurements in each group and season was respectmeans to the were different environments in In general, within each environment lessconducted than 5% ofwith geometric above 0.2 μT across which the child stayed during each measurement day, with identified through the information in all groups and seasons. The highest exposed groups 95th percentile higher than 0.1provided μT across the time-activity diary. Figure 6 presents the exposure within different activities as box-plots of the the different environments were always the PL and OTHER groups. In detail, for the PL group the summary measures geometric mean,were arithmetic mean) of the field in Specifically, each season highest exposure was(median, observed when children at home during the magnetic day and outside. andhighest group relative to each environment (i.e., at home during all day and observed night (hdin + hn), and separately the maximum values found at home were in almost cases children living at a (hd and hn), at school (s), and outdoors (o)) in which the child stayed during each 24-h personal distance
Environmental Research and Public Health Article
Children’s Personal Exposure Measurements to Extremely Low Frequency Magnetic Fields in Italy Ilaria Liorni 1, *, Marta Parazzini 1 , Benjamin Struchen 2,3 , Serena Fiocchi 1 , Martin Röösli 2,3 and Paolo Ravazzani 1 1
2 3
*
CNR Consiglio Nazionale delle Ricerche, Istituto di Elettronica e di Ingegneria dell’Informazione e delle Telecomunicazioni IEIIT, Piazza Leonardo da Vinci, Milano 20133, Italy; [email protected] (M.P.); [email protected] (S.F.); [email protected] (P.R.) Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel 4002, Switzerland; [email protected] (B.S.); [email protected] (M.R.) University of Basel, Basel 4003, Switzerland Correspondence: [email protected]; Tel.: +39-02-2399-3395
Academic Editor: Irena Cosic Received: 3 March 2016; Accepted: 26 May 2016; Published: 31 May 2016
Abstract: Extremely low frequency magnetic fields (ELF-MFs) exposure is still a topic of concern due to their possible impact on children’s health. Although epidemiological studies claimed an evidence of a possible association between ELF-MF above 0.4 µT and childhood leukemia, biological mechanisms able to support a causal relationship between ELF-MF and this disease were not found yet. To provide further knowledge about children’s ELF-MF exposure correlated to children’s daily activities, a measurement study was conducted in Milan (Italy). Eighty-six children were recruited, 52 of whom were specifically chosen with respect to the distance to power lines and built-in transformers to oversample potentially highly exposed children. Personal and bedroom measurements were performed for each child in two different seasons. The major outcomes of this study are: (1) median values over 24-h personal and bedroom measurements were 0.001; *** calculated p ď 0.001). Reference for “study group”: reference “season”: On average, it was that children are used to OTHER; spending 42% offorthe day at summer; home during reference for “measurement type”: bedroom. the night, 28% during the day, 18% of the daily time at school, and 10% outdoors. The remaining time of about 2% was indicated by parents as time spent indoors in a place different from home; however, Innot general, children the PL In and OTHERchildren groups spent are always it was considered in within this analysis. general, more more time exposed at home than in thechildren winter belonging to TRANSF group, as previously observed above. Seasonal variations have no significant period than in summer (+4%), while in the summer children spent more time outdoors than in the effect on exposure, as well as measurement type apart from a significant difference in the arithmetic winter (+3%). meanFigure of personal andsimilar bedroom measurements, in measures the formerofshowing an, onfield average, around 6 shows distributions for allresulting summary the magnetic in the same 30% higher exposure. environment for each group and in both seasons. For this reason the results are discussed only in children’s were value. analyzed over each 24-h period, an analysis of the personal termsOnce of the trend of measurements the geometric mean measurements in each group and season was respectmeans to the were different environments in In general, within each environment lessconducted than 5% ofwith geometric above 0.2 μT across which the child stayed during each measurement day, with identified through the information in all groups and seasons. The highest exposed groups 95th percentile higher than 0.1provided μT across the time-activity diary. Figure 6 presents the exposure within different activities as box-plots of the the different environments were always the PL and OTHER groups. In detail, for the PL group the summary measures geometric mean,were arithmetic mean) of the field in Specifically, each season highest exposure was(median, observed when children at home during the magnetic day and outside. andhighest group relative to each environment (i.e., at home during all day and observed night (hdin + hn), and separately the maximum values found at home were in almost cases children living at a (hd and hn), at school (s), and outdoors (o)) in which the child stayed during each 24-h personal distance
