Eeftens Marloes, Struchen Benjamin, Roser Katharina, Zahner Marco, Fröhlich Jürg, Röösli Martin
Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland.
University of Basel, Basel, Switzerland.
Bioelectromagnetics. 2018 Oct;39(7):529-538. doi: 10.1002/bem.22142. Epub 2018 Oct 18.
Portable devices measuring radiofrequency electromagnetic fields (RF-EMF) are affected by crosstalk: signals originating in one frequency band that are unintentionally registered in another. If this is not corrected, total exposure to RF-EMF is biased, particularly affecting closely spaced frequency bands such as GSM 1800 downlink (1,805-1,880 MHz), DECT (1,880-1,900 MHz), and UMTS uplink (1,920-1,980 MHz). This study presents an approach to detect and correct crosstalk in RF-EMF measurements, taking into account the real-life setting in which crosstalk is intermittently present, depending on the exact frequency of the signal. Personal measurements from 115 volunteers from Zurich canton, Switzerland were analyzed. Crosstalk-affected observations were identified by correlation analysis, and replaced by the median value of the unaffected observations, measured during the same activity. DECT is frequently a victim of crosstalk, and an average of 43% of observations was corrected, resulting in an average exposure reduction of 38%. GSM 1800 downlink and UMTS uplink were less often corrected (6.9% and 8.9%), resulting in minor reductions in exposure (7.1% and 0.92%). The contribution of DECT to total RF-EMF exposure is typically already low (3.2%), but is further reduced after correction (3.0%). Crosstalk corrections reduced the total exposure by 1.0% on average. Some individuals had a larger reduction of up to 16%. The code developed to make the corrections is provided for free as an R function which is easily applied to any time series of EMF measurements. Bioelectromagnetics. 39:529-538, 2018. © 2018 Wiley Periodicals, Inc.
测量射频电磁场（RF-EMF）的便携式设备会受到串扰影响：一个频段产生的信号会意外地在另一个频段被记录下来。如果不对此进行校正，RF-EMF的总暴露量就会有偏差，尤其会影响诸如GSM 1800下行链路（1805 - 1880 MHz）、数字增强无绳通信（DECT，1880 - 1900 MHz）和通用移动通信系统（UMTS）上行链路（1920 - 1980 MHz）等间隔较近的频段。本研究提出了一种在RF-EMF测量中检测和校正串扰的方法，该方法考虑了串扰会根据信号的确切频率间歇性出现的实际情况。分析了来自瑞士苏黎世州115名志愿者的个人测量数据。通过相关性分析识别出受串扰影响的观测值，并用在同一活动期间测量的未受影响观测值的中位数进行替换。DECT经常是串扰的受害者，平均43%的观测值得到了校正，导致平均暴露量降低了38%。GSM 1800下行链路和UMTS上行链路得到校正的情况较少（分别为6.9%和8.9%），暴露量减少幅度较小（分别为7.1%和0.92%）。DECT对总RF-EMF暴露的贡献通常已经很低（3.2%），但校正后进一步降低（3.0%）。串扰校正平均使总暴露量降低了1.0%。一些个体的降低幅度更大，可达16%。用于进行校正的代码作为一个R函数免费提供，该函数可轻松应用于任何EMF测量的时间序列。《生物电磁学》。2018年，第39卷，第529 - 538页。© 2018威利期刊公司。
