Šuka Darko, Pejović Predrag, Simić-Pejović Mirjana
University of East Sarajevo, Faculty of Electrical Engineering, East Sarajevo, Bosnia and Herzegovina.
University of Belgrade, School of Electrical Engineering, Belgrade, Serbia.
Radiat Prot Dosimetry. 2019 Dec 31;187(2):191-214. doi: 10.1093/rpd/ncz154.
Since EMF levels from wireless telecommunication networks are non-stationary and exhibit large temporal variations, the use of continuous measurements during extended periods (preferably 24 h or longer) with a data-logging system is required. Because of the short-term variations of E field, the 6-min measurements and 6-min averaged results to obtain the mean level strength at a given place appear to be dependent on the time of measurements during the day. This paper presents a new (integral-based) measure to evaluate electromagnetic exposure. The new measure is a pure physical descriptor of the amount of exposed energy density (a parameter accumulated from instantaneous power density values in time). To confirm previous observations, continuous measurements with personal exposure metre were recorded 24 h a day for two weeks at every location in urban area, 14 different locations in total. Additionally, to check temporal variations and repeatability of exposure assessment, a week of prolonged measurements was taken 6 months later, making in total three weeks of measurements at 2 locations. Day-to-day repeatability of RF-EMF exposure was analysed through the time-averaged and integral-based measure. The analysis is based on approximately 5.1 million data samples (1.7 million for each band). The ratio between the maximum and minimum instantaneous (maximum and minimum 6-min averaged) E field values during the day could reach up to 25 dB (20 dB). Therefore, great variability in the results may occur. By applying the 24 h time-averaged and integral-based measure on a 24 h data set of measurements, the variability of daily exposure could stay within ±20% of the week mean level obtained either with the time-averaged or integral-based measure. Both, the time-averaged E field and integral-based power density exposures of the general public in all locations were found to be well below the general public exposure limits of the ICNIRP guidelines.
由于无线通信网络的电磁场水平是非平稳的，且呈现出较大的时间变化，因此需要使用数据记录系统在较长时间段（最好是24小时或更长时间）内进行连续测量。由于电场的短期变化，在给定地点通过6分钟测量和6分钟平均结果来获取平均场强似乎取决于一天中的测量时间。本文提出了一种新的（基于积分的）方法来评估电磁暴露。新方法是对暴露能量密度量的一个纯物理描述符（一个从时间上的瞬时功率密度值累积得到的参数）。为了证实之前的观察结果，在城市区域的每个位置，每天24小时使用个人暴露计进行连续测量，共14个不同位置，持续两周。此外，为了检查暴露评估的时间变化和可重复性，6个月后进行了为期一周的延长测量，在2个位置总共进行了三周的测量。通过时间平均和基于积分的方法分析了射频电磁场暴露的每日可重复性。该分析基于大约510万个数据样本（每个频段170万个）。白天最大和最小瞬时（最大和最小6分钟平均）电场值之间的比率可达25分贝（20分贝）。因此，结果可能会有很大的变化。通过将24小时时间平均和基于积分的方法应用于24小时测量数据集，每日暴露的变化性可以保持在通过时间平均或基于积分的方法获得的周平均水平的±20%以内。所有位置的公众的时间平均电场暴露和基于积分的功率密度暴露均被发现远低于国际非电离辐射防护委员会（ICNIRP）指南中的公众暴露限值。
