Ruzic R., Jerman I., Kustor V., Jeglic A., Fefer D. (1994): The effects of TV monitor on germinating spruce seeds. Fourth International Scientific Conference WWDU '94. Book of short papers, October 2-5, 1994. University of Milan, Milano, pp. E22-24.
 
Objectives
Our civilization becomes more and more aware that non-ionizing EM radiation can have profound biological, either negative or positive, effects (2). It is the reason why VDU-s, being a very broad source of EM radiation and also widely used, are of special interest to the researchers. The reports about the effects on humans are quite contradictory, some of them claiming VDU-s have no biological effects (3,5,7), while others claiming the reverse (6). It is obvious that the supposed effects depend mostly on intensity and frequency spectrum of radiation, exposure time, distance from VDU-s and on environmental factors which could interact sinergistically with VDU-s' EM radiation. Power and frequency windows can also be expected (1).

To see if there are any measurable biological effects of TV monitor on biosystems we made a series of experiments using our specially developed biological sensor system, susceptible to EM radiation (4). Given the controversial reports concerning the effect of VDU-s on humans, we expected that any positive result with our sensor system, unconditioned by any possible form of (auto)suggestion, would give some additional weight to researches showing VDU-s can have real biological effects on humans.

Material and methods
Our sensor system was composed of two groups of germinating spruce seeds (Picea abies) growing in obscured petri dishes - the tested (exposed) and the comparative (unexposed) one. Each group comprised 5x100 seeds germinated in petri dishes (diameter 9 cm) with filter paper watered with distilled water and exposed 8 h/day (7-9 days) to EM radiation from color TV monitor (national producer) at different distances and average room temperature varying in different months (see Table 1), but they were the same for the control and the exposed groups. The control groups were at the distance of 450 cm behind TV set, where we couldn't measure any difference of EM radiation from the background field. We made 12 experiments: 7 with groups of normal watered seeds (N) (i.e. the seeds were watered with 3 ml first day and 2 ml third day) and 5 with groups of seeds exposed to controlled mild drought stress (S) (i.e. the seeds were watered 2 ml first day and 3 ml 5 day).

The background EM fields did not exceed B=111 nT, E=1,6 V/m at 50 Hz and B=0,7nT, E=0,07 V/m at 16 kHz. EM fields was measured with field strenghtmeters HI-3603 (at 16 kHz) and HI-3604 (at 50 Hz). The values before (+) and behind (-) TV set was as shown on the Table 2.

At the end of every experiment the lengths of radicula (root) were measured and statistically analyzed. The comparison was made between the exposed and unexposed groups of germinating seeds and the statistical difference evaluated with t-test. The total growth (average growth times number of germinated (N)) was also calculated as it was found to be very informative about the exposure effects.

Experimental design
* 1st experiment: N groups exposed 7, 8, and 9 days; the distance from 23 to 48 cm in front of monitor was changed every day, (November)
* 2nd experiment: S groups, repeated 1st exp. (November)
* 3rd experiment: N groups exposed for 7 days at the distances 35, 90 and 160 cm in front of the monitor, (December)
* 4th experiment: S groups exposed 9 days at the same distances as in the 3rd experiment, (December)
* 5th experiment: repeated 3rd exp., besides, a group at 50 cm behind the TV was added, (January)
* 6th experiment: repeated 4th exp., besides, a group at 50 cm behind the TV was added, (January)
* 7th experiment: N groups exposed for 7 days at the distances 25, 50, 70, 90 and 110 cm in front of the monitor, (February)
* 8th experiment: repeated 7th experiment, (March)
* 9th experiment: repeated 3rd experiment, (July)
* 10th experiment: repeated 4th experiment, (July)
* 11th experiment: repeated 3rd experiment (August)
* 12th experiment: repeated 4th experiment (August)
Results
The results are also given on the graph:

The results in winter months (Nov. Dec. Jan.) show mostly stimulatory results, more pronounced with the S than with the N groups. Many results with both types of groups are also statistically significant. There were no significant effects observed behind the TV monitor. In the next two months (Feb., March) the results were varying, showing no clear effect, however at the distance 110 cm exposure yielded significantly inhibitory results in February (N groups). The experiments repeated in July and August shows tendency to inhibition of growth with no clear rules concerning distance. If we calculate the total growth of seedlings with no consideration of the distance of the exposed from the TV monitor, we see that the effect of radiation was stimulatory in winter months and inhibitory in summer months while the general effect on the growth of S groups is more stimulatory than on the N ones. If we consider the distance, the most pronounced effects were at shorter distances (25-50 cm) with the S groups while the N groups revealed no such preferences.

Scientific relevance
Our results show:

1. Our biological sensor system recognized the difference between exposure to a TV monitor vs. non-exposure. The response to exposure is highly non-linear.

with the researchers that reported no effects of VDU-s on physiological properties of man (3,5,7) the exposition time was much shorter than in our experiments. Lindbohm et al. (6) reported significant effects on the rate of abortion at a little higher magnetic field density (above 0,9 T) than ours.

2. There is a pronounced seasonal effect on the total growth of the exposed groups; they react to exposure positively in winter months, intermediary in Feb. and March and negatively (inhibition of growth) in summer. This effect is stronger than the effect of different exposure distances. Very similar seasonal variation of the response to the EMF exposure was seen in our previous experiments with chestnut grown in tissue culture (8).

3. On the average the stressed groups reacted more positively to the exposure than the unstressed ones, i.e. the total average (for all distances) growth in winter season was less inhibited and in summer it was higher.

4. The effect with the stressed groups is more pronounced at shorter distances. We suppose the electric field to be responsible for this because of much bigger differences between the exposed and control groups at shorter distances, where the electric field values were more pronounced than the magnetic ones.

5. Because of the difference in the average temperature for both groups throughout the year it seems possible that EM radiation has inhibitory effects when the temperature is higher (about 27o C) and stimulatory when the temperature is lower (about 23o C). But comparisons among the months from Nov. to March show no such correlation between average temperature and the growth of the exposed groups.

6. Naturally, the comparison between humans and plants should not be direct. Yet more statistically significant results with the groups S (drought stress) vs. groups N indicate the possibility of VDU radiation enhancing some already present stress in organisms. And this is relevant also for humans.

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