Measurement of Low-level radiofrequency electromagnetic fields in the human environment

Very high radiofrequency radiation at Skeppsbron in Stockholm, Sweden from mobile phone base station antennas positioned close to pedestrians' heads

In urban environment there is a constant increase of public exposure to radiofrequency electromagnetic fields from mobile phone base stations. With the placement of mobile phone base station antennas radiofrequency hotspots emerge. This study investigates an area at Skeppsbron street in Stockholm, Sweden with an aggregation of base station antennas placed at low level close to pedestrians' heads. Detailed spatial distribution measurements were performed with 1) a radiofrequency broadband analyzer and 2) a portable exposimeter. The results display a greatly uneven distribution of the radiofrequency field with hotspots. The highest spatial average across all quadrat cells was 12.1 V m⁻¹ (388 mW m⁻²), whereas the maximum recorded reading from the entire area was 31.6 V m⁻¹ (2648 mW m⁻²). Exposimeter measurements show that the majority of exposure is due to mobile phone downlink bands. Most dominant are 2600 and 2100 MHz bands used by 4G and 3G mobile phone services, respectively. The average radiofrequency radiation values from the earlier studies show that the level of ambient RF radiation exposure in Stockholm is increasing. This study concluded that mobile phone base station antennas at Skeppsbron, Stockholm are examples of poor radiofrequency infrastructure design which brings upon highly elevated exposure levels to popular seaside promenade and a busy traffic street.

Measurement of Base Transceiver Station Exposure in the Extra-Village Environment- A Pilot Study

In recent years, communication using electromagnetic (EM) radiation became an integral part of our lives. As a result, there is a large number of base transceiver stations (BTSs) which act as a source of high EM exposure for inhabitants mainly in the “hot-spot” areas. They employ higher values of radiation, thus, providing potentially harmful effects on living or working environment. The aim of this pilot study was to study a distribution of hot-spots and EMF power in a vicinity of BTSs. BTS was located in an extra-village area at least 500 m away from the nearest city or surrounded villages in the district of Martin. The targeted area of EM radiation from the BTS was divided into two smaller zones, the right and the left. For a better visualization, topographic maps were created. Using spectral analyzer Aaronia Spectran HF-6085, intensities of EMF within the frequency range from 880 – 960 MHz (GSM900) were recorded. Maximum values of EMF power flux density were 146.827 μW/m2 in horizontal and 96.448 μW/m2 in vertical plane. Minimal va lues were 0.052 μW/m2 in horizontal and 0.179 μW/m2 vertical plane respectively. The maps revealed two hotspots in the left zone and also two (smaller and larger) hotspots in the right zone. Our values were below the actual limits given by the Slovak Republic and the International Commission for Non-Ionizing Radiation Protection (ICNIRP) safety guidelines. However, the values from the hotspots were above the limits suggested by the BioInitiative Report. Our results indicate an elevation of EMF values in the hot-spots even in the extra-village areas. Further studies are needed to analyze in detail EMF parameters in the hot-spots, and their effects on living and working environments.

Classifier Spot Count Optimization of Automated Fluorescent Slide Scanning System

Purpose: Ionizing radiation induced foci (IRIF) known also as DNA repair foci represent the most sensitive endpoint for assessing DNA double strand breaks (DSB). IRIF are usually visualized and enumerated with the aid of fluorescence microscopy using antibodies to γH2AX and 53BP1. Although several approaches and software packages were developed for the quantification of IRIF, not one of them was commonly accepted and inter-laboratory variability in the outputs was reported. In this study, the sensitization of Metafer software to counting also small appearing IRIF was validated.

Materials and Methods: Human lymphocytes were γ-irradiated at a dose of 2 Gy. The cells were fixed at 0.5, 1, 2, and 18 hours post-irradiation, permeabilized and IRIF were immunostained using appropriate antibodies. Cell images were acquired with the automatic Metafer system. Radiation-induced γH2AX and 53BP1 foci were enumerated using either manual counting (JCountPro program) or the Metafer software (after its classifier optimization has been done) and compared. The statistical analysis was performed using One-way ANOVA.

Results: The enumeration of 53BP1, γH2AX foci manually by JCountPro did not statistically significantly differ from the automatic one performed with the optimized Metafer classifier. A detailed step-by-step protocol of this successful optimization is described in this study.

Conclusions: We concluded that the Metafer software after the optimization was efficient in objectively enumerating IRIF, having a potential for usage in clinics and molecular epidemiology.

Biological Effects of a Low-Frequency Electromagnetic Field on Yeast Cells of the Genus Saccharomyces Cerevisiae

Background: Although the scientific community is extensively concerned with the effects of the EMF, the unambiguous explanation of its effects on living structures is still lacking.

Goals: The goal of the study was to evaluate the effect of a low-frequency (LF) electromagnetic field (EMF) on the growth and multiplication of the yeast Saccharomyces cerevisiae.

Methods: Yeast cells were exposed to a frequency of 900 Hz and a magnetic flux density of 2.3 mT. The duration of each experiment was 8 hours, in the beginning of the measurement the value of frequency, rms (root mean square) value of electric current (2 A), and magnetic flux density were fixed set on the exposure device. A paired experiment was performed, a sample exposed to EMF, and a sample shielded from the field. Subsequently, samples were taken every two hours, the number of cells was recorded, and then the concentration of the yeast cells was evaluated at time points. The time points reflected the exposure time of the samples exposed to EMF.

Results: The results indicate that LF EMF at given parameters has an inhibitory effect on the growth and multiplication of yeast cells.

Conclusion: Exposure to EMF can cause the differences in growth dynamics between cells exposed to the field and the unexposed ones.