A study was conducted in the Netherlands to investigate the association between exposure to environmental radiofrequency electromagnetic fields from outdoor or indoor sources and the use of mobile or cordless phones and sleep problems of children, aged 7 years.
Parents completed the Child Sleep Habits Questionnaire (CSHQ), a 33-item questionnaire developed as a sleep screening tool for school-aged children.
Three behavioural or medical-condition related sleep parameters (bedtime resistance, sleep anxiety and sleep disordered breathing) were evaluated as control parameters because these were a priori hypothezised not to be associated with radiofrequency electromagnetic fields.
|Reference group 1||residential exposure to mobile phone base station: low (< 50th percentile)|
|Group 2||residential exposure to mobile phone base station: medium (50-90th percentiles)|
|Group 3||residential exposure to mobile phone base station: high (> 90th percentile)|
|Reference group 4||indoor sources: no WiFi or cordless phone|
|Group 5||indoor sources: WiFi: yes, cordless phone: no|
|Group 6||indoor sources: WiFi: no, cordless phone: yes|
|Group 7||indoor sources: WiFi and cordless phone|
|Reference group 8||mobile phone use at the age of 5 years: no|
|Group 9||mobile phone use at the age of 5 years: < one time per week|
|Group 10||mobile phone use at the age of 5 years: 1 - 2 times per week|
|Group 11||mobile phone use at the age of 5 years: ≥ 3 times per week|
|Reference group 12||cordless phone use at the age of 5 years: no|
|Group 13||cordless phone use at the age of 5 years: < one time per week|
|Group 14||cordless phone use at the age of 5 years: 1 - 2 times per week|
|Group 15||cordless phone use at the age of 5 years: ≥ 3 times per week|
Sleep onset delay, night wakening, parasomnia and daytime sleepiness were not associated with residential exposure to radiofrequency electromagnetic fields from mobile phone base stations. Sleep duration scores were associated with radiofrequency electromagnetic fields levels from base stations (group 3). Higher mobile phone use was associated with less favorable sleep duration, night wakening and parasomnia, and also with bedtime resistance (control sleep paramater). Cordless phone use was not related to any of the sleeping scores.
Based on the different results across the evaluated radiofrequency electromagnetic fields exposure sources and the observed association between mobile phone use and the negative control sleep scale, the authors concluded that sleep quality in 7-year old children is not associated with the exposure to radiofrequency electromagnetic fields, but potentially with other factors that are related to mobile phone usage.