Heinrich S, Thomas S, Heumann C, von Kries R, Radon K. Association between exposure to radiofrequency electromagnetic fields assessed by dosimetry and acute symptoms in children and adolescents: a population based cross-sectional study. Environ Health. Nov 25, 2010. Ahead of print.
In Germany, 27% of the population report concerns about potential health effects of radiofrequency electromagnetic fields (RF EMFs). Most of those who are concerned report that unspecific symptoms (e.g. headaches) appear during the exposure. Therefore, acute effects on health and well-being are of special interest. Children and adolescents are an important age group due to their high usage of mobile phones and possibly higher vulnerability of the developing nervous system. Few studies investigated potential adverse health effects of RF EMF exposure in young people, and these studies were based on self-reported exposures.
The objective of the study was to investigate, using personal dosimeters, the possible association between the exposure to RF EMF from all sources (mobile phones, DECT phones, base stations, WLAN) and acute health effects in children and adolescents.
Participants were 1,484 children (aged 8-12 years) and 1,508 adolescents (aged 13-17 years). Data on participants’ socio-demographic and other characteristics were collected during a computer-assisted personal interview. Some information on the children was collected from their parents. Exposure was measured for 24 hours using a personal dosimeter placed on the upper arm opposite to the side of mobile phone use. On that day, the participants recorded their acute symptoms at noon and before bedtime as well as their mobile phone use in the previous hours. The following symptoms were considered: headache, irritation, nervousness, dizziness, fatigue, and concentration problems. Two separate analyses were conducted: for the association between exposure in the morning and symptoms at noon, and for the association between exposure in the afternoon and symptoms in the evening (at bedtime).
Results and Interpretation
The measured levels of exposure were far below the reference levels of the International Commission on Non-Ionizing Radiation Protection (ICNIRP). Significantly more concentration problems in the evening were reported by children with highest exposures measured during afternoon hours: odds ratio (OR) for the 4th quartile of exposure relative to the 1st quartile was 1.55 (95% CI 1.02; 2.33). The adolescents in the 4th quartile of exposure measured during morning hours reported headaches at noon significantly more often than the adolescents in the 1st quartile: OR= 1.50 (95% CI 1.03-2.19). There was also a significant increase in the prevalence of irritation at bedtime reported by adolescents who were in the 4th quartile of exposure measured during the afternoon: OR=1.79; (95% CI 1.23-2.61). Since the observed significant associations were of borderline significance and were not consistent over the two time points (morning and afternoon), the authors believe that these associations were either due to chance or due to multiple testing. Moreover, when 10% of participants with highest measured exposures were compared with the remaining 90%, the significant associations were not confirmed. When self-reported mobile phone use was taken as a proxy of exposure, significantly increased ORs were obtained for headache, irritation and fatigue at noon after >5 min of mobile phone use during morning hours reported by adolescents. No significant associations with self-reported exposure were obtained for children. Although measured and self-reported exposures were significantly associated, about 70% of the participants would be misclassified if self-reported exposure were used as a proxy for the real exposure.
The authors have concluded that the few observed significant associations between measured exposures to RF EMFs and acute symptoms in children and adolescents were likely chance findings.