Overview of research methods

There are several methods to study potential effects of 50 Hz electric and magnetic fields on health.

Epidemiological studies should normally be the most interesting considering human health because they take into account individuals in their environment. In reality this is not so: epidemiology provides correlation but not causal relationships. Other studies are therefore necessary for a better understanding of pathophysiological working mechanisms and to enhance the credibility of epidemiological studies:

  • controlled human clinical trials,
  • in vivo investigations and
  • in vitro studies.

Well-conducted in vitro studies can reveal mechanisms of action at the cellular or molecular level that can explain pathophysiological effects. But the results of in vitro studies do not necessarily mean that an effect will be observed in vivo.

Epidemiology – Research for the existence of a statistical association between a given factor and the appearance of a disease

Human studies – Volunteers are subjected to 50 Hz electric and magnetic fields for short periods of time, under controlled exposure. Multiple functions are analysed

In vivo studies – Research of effects of electric and magnetic fields on animals

In vitro studies – Research for mechanisms of action of electric and magnetic fields on cells

Pyramide des études

Modelling – Computer simulation of electromagnetic fields, for example to estimate the distribution of ELF fields induced in the human body by overhead power lines or contact currents

Note: A single study is not enough!

Results of a single study cannot be used to draw conlusions. They can only be used to emit hypothesis, that will need to be confirmed by the replication of this study and by other studies.

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