József Bakos

Effects of Whole-Body 50-Hz Magnetic Field Exposure on Mouse Leydig Cells

The main goal of this study was to evaluate the possible effect of whole-body magnetic field (MF) exposure on the steroidogenic capacity of Leydig cells in vitro. In four separate experiments, male CFLP mice were exposed to sinusoidal 50-Hz, 100-μT MF. The duration of exposure was 23.5 h/day over a period of 14 days. At the end of the exposure, interstitial (Leydig) cells were isolated from the testicles of the sham-exposed and exposed animals. The cells were cultured for 48 h in the presence or absence of 1, 10, or 100 mIU/ml human chorionic gonadotropin (hCG). The luteinizing hormone (LH) analog hCG was used to check the testosterone (T) response of the sham-exposed controls and to evaluate the possible effect of the whole-body MF exposure on the steroidogenic capacity of Leydig cells in vitro. Testosterone content of the culture media and blood sera was measured by radioimmunoassay (RIA). In the cultures obtained from MF-exposed animals, the hCG-stimulated T response was significanly higher (p < 0.01) compared with the sham-exposed controls, while the basal T production of cells and the level of serum T remained unaltered. No MF exposure—related histopathological alterations were found in testicles, epididymes, adrenals, prostates, and pituitary glands. The MF exposure did not affect the animal growth rate and the observed hematologic and serum chemical variables. Our results indicate a presumably direct effect of whole-body MF exposure on the hCG-stimulated steroidogenic response of mouse Leydig cells.

Exposure to 50 Hz magnetic field in apartment buildings with built-in transformer stations in Hungary

Exposure to 50 Hz magnetic field (MF) was evaluated in 31 multi-level apartment buildings with built-in step-down transformer stations. In each building, three apartments were selected: one apartment located immediately above the transformer room (index apartment), one located on the same floor and one on a higher floor. The mean value of measured MFs was 0.98 microT in apartments above transformers, 0.13 microT on the same floor, and 0.1 microT in on higher floors. The mean measured MF value was higher than 0.2 microT in 30 (97%) index apartments, 4 (14%) on the same floor as the index apartments and 4 (13%) on higher floors. The corresponding numbers were 25 (81%), 0 and 0, respectively, when 0.4 microT was used as cut-point. It is concluded that apartments in building with built-in transformers can be reliably classified into high and low-exposure categories based on their location in relation to transformers.

Urinary 6-sulphatoxymelatonin excretion is increased in rats after 24 hours of exposure to vertical 50 Hz, 100 μT magnetic field

The effect of exposure to a 50 Hz, vertical magnetic field on the excretion of urinary 6-sulphatoxymelatonin (aMT6s) of rats was studied in a self-controlled experiment. Ten male Wistar rats were kept under 9:15 h light: dark conditions in metabolic cages. The rats were exposed to 1.0 or 100 microT flux density for 24 h. The excretion of aMT6s, which is the primary metabolite of melatonin in the urine, did not show a statistically significant decrease, as measured by 125I radioimmunoassay, during or after magnetic field exposure of rats to either flux density. At 100 microT flux density, the increase of aMT6s excretion on the day after exposure was statistically significant (P < .02), compared with the value under exposure, but was not significant compared with the baseline values before exposure.

Effect of continuous-wave and amplitude-modulated 2.45 GHz microwave radiation on the liver and brain aminoacyl-transfer RNA synthetases of in utero exposed mice

Investigations have been carried out concerning the effects of microwave (MW) exposure on the aminoacyl-transfer ribonucleic acid (tRNA) synthetase of the progeny of females that were exposed during their entire period of gestation (19 days). The changes caused by continuous-wave (CW) and amplitude-modulated (AM) MW radiation have been compared. CFLP mice were exposed to MW radiation for 100 min each day in an anechoic room. The MW frequency was 2.45 GHz, and the amplitude modulation had a 50 Hz rectangular waveform (on/off ratio, 50/50%). The average power density exposure was 3 mW/cm2, and the whole body specific absorption rate (SAR) was 4.23 +/- 0.63 W/kg. The weight and mortality of the progeny were followed until postnatal day 24. Aminoacyl-tRNA synthetase enzymes and tRNA from the brains and livers of the offspring (461 exposed, 487 control) were isolated. The aminoacyl-tRNA synthetase activities were determined. The postnatal increase of body weight and organ weight was not influenced by the prenatal MW radiation. The activity of enzyme isolated from the brain showed a significant decrease after CW MW exposure, but the changes were not significant after 50 Hz AM MW exposure. The activity of the enzyme isolated from liver increased under CW and 50 Hz modulated MW.

Review of Studies Concerning Electromagnetic Field (EMF) Exposure Assessment in Europe: Low Frequency Fields (50 Hz-100 kHz).

We aimed to review the findings of exposure assessment studies done in European countries on the exposure of the general public to low frequency electric and magnetic fields (EMFs) of various frequencies. The study shows that outdoor average extremely low frequency magnetic fields (ELF-MF) in public areas in urban environments range between 0.05 and 0.2 µT in terms of flux densities, but stronger values (of the order of a few µT) may occur directly beneath high-voltage power lines, at the walls of transformer buildings, and at the boundary fences of substations. In the indoor environment, high values have been measured close to several domestic appliances (up to the mT range), some of which are held close to the body, e.g., hair dryers, electric shavers. Common sources of exposure to intermediate frequencies (IF) include induction cookers, compact fluorescent lamps, inductive charging systems for electric cars and security or anti-theft devices. No systematic measurement surveys or personal exposimetry data for the IF range have been carried out and only a few reports on measurements of EMFs around such devices are mentioned. According to the available European exposure assessment studies, three population exposure categories were classified by the authors regarding the possible future risk analysis. This classification should be considered a crucial advancement for exposure assessment, which is a mandatory step in any future health risk assessment of EMFs exposure.

Spot measurements of intermediate frequency electric fields in the vicinity of compact fluorescent lamps

Starting in 2009, certain types of incandescent light bulbs will be withdrawn from the market in the European Union and elsewhere. However, compact fluorescent lamps that are among the candidates to replace them produce intermediate frequency electric fields (EFs) much higher than any other device or appliance previously available to the general public. Measurement results of these EFs showed that the maximum recorded EF strength in the 1.2-100 kHz frequency range in close proximity to the lamps was > 42 V m(-1) for all tested lamps. In nine cases, the field strength exceeded 87 V m(-1) and the highest measured value was 216 V m(-1).

Urinary 6-Sulphatoxymelatonin Excretion of Rats is not Changed by 24 Hours of Exposure to A Horizontal 50-HZ, 100-μT Magnetic Field

The effect of exposure to a 50-Hz horizontal magnetic field on the excretion of urinary 6-sulphatoxymelatonin (aMT6s) into nocturnal urine of rats was studied. Two directions of the horizontal magnetic field, parallel and perpendicular to the magnetic north, were investigated in two separate experiments. Twenty-two male Wistar rats were kept in metabolic cages under 9:15 1ight:dark conditions for 5 days; the nocturnal urine was collected daily. The concentration of aMT6s in the rat urine was measured by 1251-radioimmunoassay. After the first 2 days, the rats were exposed to 100or 1-pT flux density magnetic fields for 24 h. On the fourth and fifth days, the urine collection was continued without exposure. It was found that the excretion of aMT6s, the primary urinary metabolite of melatonin, did not show statistically significant alteration during or after 50-Hz horizontal magnetic field exposure of rats to 100 or 1 pT flux density.

Public exposure to RF from installed sources: Site measurements and Personal Exposimetry

The aim of present study is to measure the RF exposure at the location accessible to public with site measurements and the exposure to RF with personal dosimeter. The site measurements were spot measurements (n=292 sites) with spectrum analyzer and broadband RF antenna in three axis and the resultant was calculated according to the sum of E-field strength vector components. The area and type of the measurement sites were also classified. In the other part of the study the applicability of the RF Dosimeter (RF Personal ExposiMeter - PEM) for human exposure assessment in the real urban environment was investigated. The RF exposure levels, at the living area of general public were collected and evaluated according to the EU Recommendation (1999/519/EC) and ICNIRP reference levels [1,2]. At the present state of data collection and evaluation, the median value of exposure in GSM band was 0.025 mikrowatt/cm2 at outdoor, 0.013 mikrowatt/cm2 at indoor sites respectively. Within 300 m of the base station no clear expression could be found between the exposure levels and distances similarly to other recent studies. The results from personal exposure showed that one third of the participants spent 40¿70 % percent of 24h recording time above the detection limits (0.05 V/m) and half of subjects spent less than 10 %. The highest exposure was detected during the travelling period and the lowest in the bed at home.

Ultraviolet radiation and skin disorders in Hungary

The measurements of ozone content, evaluation of UV radiation and their links with skin cancer in Hungary have been studied for the last three decades. The total ozone content of an air column above Hungary has been measured by the Hungarian Meteorological Service since 1969 using Dobson-spectrophotometer. The measurements of UV-B radiation started in 1993 by three Robertson-Berger equipments and LI-1800 spectroradiometer. It was found a decreasing trend of ozone content 1.7% per 10 years. Since 1991/92 winter the ozone conditions of the stratosphere have been perturbed. Such low ozone values that have been observed in two winters successively never occurred. Deficits in monthly averages: 1991 Dec: -6%, 1992 Jan; -17%, Feb; -9%, Dec; - 10%, 1993 Jan; -16%, Feb; -17%. Statistical analysis of the patient material of the Eastern region of Hungary, characterized by a rather high intensity of sunlight and UV rays, has shown a significant increase in light induced skin disorders in recent decades. Ninety-six photoallergic and phototoxic cases followed up in 1966 rose to 336 (1977) and 788 (1993) whereas the numbers of patients with basal cell carcinoma and malignant melanoma increased two- and fivefold, respectively, from 1966 to 1993. A UV personal dosimeter has been developed to measure exposure of the skin to UV-B radiation. These SUNTEST UV-sensitive strips for general public are produced by FORTE Photochemical Company.