Study type: Medical/biological study (experimental study)

Frequent cellular phone use modifies hypothalamic-pituitary-adrenal axis response to a cellular phone call after mental stress in healthy children and adolescents: A pilot study. med./bio.

Published in: Sci Total Environ 2015; 536: 182-188

Aim of study (acc. to author)

The effects of mental stress and acute exposure to a mobile phone on the salivary cortisol levels of children, which were categorized according to the extent of their everyday mobile phone usage, should be investigated.

Background/further details

Cortisol is the final hormone of the hypothalamic-pituitary-adrenal axis and was therefore used as a marker.
28 children aged 11-14 were divided into 2 groups: 1) those who did not possess or occasionally used a mobile phone (n = 16) and 2) those who possessed and regularly used a mobile phone (n=12). All subjects participated in one session, comprising of an initial blood sample donation followed by a mental stress provocation (Trier Social Stress Test) and a final 5 minute mobile phone call. Between each block, there was an intermediate resting interval and during these intervals, a total of 5 saliva samples were taken: before the stress test (baseline value), 10 minutes after the stress test, 20 minutes after the stress test, 10 minutes after the use of the mobile phone and 20 minutes after the use of the mobile phone.

Endpoint

Exposure

Exposure Parameters
Exposure 1:
Exposure duration: continuous for 5 minutes
occassional users
  • SAR: 0.268 W/kg minimum
  • SAR: 102 W/kg maximum (probably 1.02 W/kg)
Exposure 2:
Exposure duration: continuous for 5 minutes
regular users
  • SAR: 0.57 W/kg minimum (specifications not clear)
  • SAR: 1.02 W/kg maximum (specifications not clear)

Exposure 1

Main characteristics
Frequency
Type
Exposure duration continuous for 5 minutes
Additional info occassional users
Exposure setup
Exposure source
Setup the participants were placed in supine posture on a typical metallic bed with cotton mattress, whose distance from each wall of the room was 0.7 m Π0.2 m Π3.47 m Π0.95 m; a second similar bed and a small metallic table (with experimental instruments) had been also placed in the room; each participant used their personal phone for exposure; the hypothalamus, the pituitary, the thyroid and the salivary glands of the participants were exposed to the near field, whereas the adrenal gland of tall participants might be exposed to the far field of the cellular phone antenna
Parameters
Measurand Value Type Method Mass Remarks
SAR 0.268 W/kg minimum unspecified - -
SAR 102 W/kg maximum unspecified - probably 1.02 W/kg

Exposure 2

Main characteristics
Frequency
Type
Exposure duration continuous for 5 minutes
Additional info regular users
Exposure setup
Exposure source
Parameters
Measurand Value Type Method Mass Remarks
SAR 0.57 W/kg minimum unspecified - specifications not clear
SAR 1.02 W/kg maximum unspecified - specifications not clear

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • before exposure
  • after exposure

Main outcome of study (acc. to author)

The height, weight and BMI were significantly larger in regular mobile phone users (group 2) compared to occasional user (group 1), as participants in group 2 were 2 years older on average.
Baseline salivary cortisol levels were significantly higher in group 2 compared to group 1. In group 2, no changes were observed in the cortisol levels after stress provocation and mobile phone exposure. In group 1, however, the cortisol levels decreased significantly compared to the baseline value in response to stress provocation and mobile phone exposure.
The authors conclude that the salivary cortisol level in children could be influenced by mental stress and acute exposure to a mobile phone depending on the extend of the everyday mobile phone usage.

Study character:

Study funded by

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