Exposure Variability Between 1- or 6-Minute and 30-Minute Averaging Time Lengths in Radiofrequency-Electromagnetic Field Exposure Monitoring

Abstract

Overview

Different averaging time lengths (ATLs) are widely used in radiofrequency-electromagnetic field (RF-EMF) exposure monitoring. This study evaluated variability in RF-EMF exposure associated with the ATLs of 1- and 6-min normalised to 30-min data.

Methods

• RF-EMF exposures were collected in contiguous 1-min blocks over 30 min at four sites (two outdoor and two indoor).
• 15 frequency bands of interest were analyzed.
• Frequency-band and site-specific variability in exposure between the three ATLs was assessed.

Findings

• Variability in terms of relative deviation (in dB) between 1- or 6-min and 30-min were estimated.
• The overall exposure variability (µW/m²) were compared between 1- or 6-min and 30-min blocks statistically using the quantile regression method.
• An ATL of 1-min or 6-min was considered different from 30-min if a majority of respective sub-pair comparisons across different percentiles (P5, P25, P50, P75, P95) were significantly different.

Conclusion

The study largely showed that the exposure variability (i.e., relative deviation) of different ATLs was within +/- 3 dB. Further, the overall exposure variability between 1- or 6-min and 30-min ATLs showed inconsistent outcomes. Frequency bands of broadcast and most of the mobile services < 2 GHz demonstrated overall similar exposure variability for 1-min and 6-min ATLs.

EMF Note: Consistent monitoring and accurate averaging time selections are crucial for understanding and managing health risks associated with RF-EMF exposure, as variability in exposure may affect risk assessments.