Vibration as a possible explanation for putative electromagnetic field effects:a case study on marine diatoms

Davies, M.S. and Norris, W.T. (2004). Vibration as a possible explanation for putative electromagnetic field effects:a case study on marine diatoms. International Journal of Radiation Biology, 80 (10), pp. 709-718.


Purpose: We examined the conjecture that mechanical vibration, being an uncontrolled and variable factor from one trial to another, might explain the inconsistency of results from investigations of the influence of extremely low frequency electromagnetic fields on the Ca-dependent motility of marine diatoms (Amphora coffeaeformis, strain #2038).  Materials and methods: Owing to slight differences in culture of diatoms in previous studies, culture techniques are described in detail here. Diatoms showed maximal motility in logarithmic growth and motility was dependent on external [Ca], reducing at < 0.25 mM added Ca. Ninety-six different vertical vibration treatments were applied to the petri dishes containing the agar on which the diatoms were placed. The envelope of amplitudes varied from 50-500 μm at 10 Hz to 100 nm-1 μm at 500 Hz.  Results: No significant effect of the mechanical vibrations on the motility response of diatoms was observed. We were unable to impose deliberate vibrations in a horizontal direction though some component of horizontal movement was probably present in our tests. Conclusions: The results imply that the variability of earlier experiments with extremely low frequency electromagnetic fields is unlikely to be ascribable to mechanical vibration.

Publication DOI:
Divisions: Engineering & Applied Sciences > Mechanical engineering & design
Engineering & Applied Sciences
Uncontrolled Keywords: Agricultural and Biological Sciences (miscellaneous),Radiology Nuclear Medicine and imaging,Radiological and Ultrasound Technology,Nuclear Energy and Engineering,Radiation
Full Text Link:
Related URLs:
Published Date: 2004-10
Authors: Davies, M.S.
Norris, W.T.


Item under embargo

Export / Share Citation


Additional statistics for this record