Saturday, September 29, 2018

Exposure to electromagnetic fields (EMF) – Biological effects vs health effects

We often see media articles that claim new research has found health effects from human exposure of some chemical or physical agent. In the case of electromagnetic fields (EMF), we have seen such studies claiming effects of exposure to EMF. But what is rarely discussed is whether the claimed ‘effect’ is a biological effect or indeed a health effect. What’s the difference you ask? 

In the recent MWF publication “20 years of research[1]”, we tried to explain this difference: 

Biological effects are a response to stimulus or to a change in the environment around you and are not necessarily bad for your health. Health effects are changes in health resulting from exposure to an agent or source. Eating a freezing cold ice cream can give you a ‘brain-freeze’ (ice-cream headache), a sensation which goes away a short time after you stop eating it. Going for a run or sitting in a sauna will cause your body temperature to rise. These biological effects are not considered health effects because the result is temporary and not detrimental to your health.

Further explanations on the difference between “biological effects” and “health effects” in particular in regards to exposure to EMF, can be found in the factsheet of the World Health Organization[2](WHO) on electromagnetic fields. There the WHO states: 

Biological effects are measurable responses to a stimulus or to a change in the environment. These changes are not necessarily harmful to your health. For example, listening to music, reading a book, eating an apple or playing tennis will produce a range of biological effects. Nevertheless, none of these activities is expected to cause health effects. The body has sophisticated mechanisms to adjust to the many and varied influences we encounter in our environment. Ongoing change forms a normal part of our lives. But, of course, the body does not possess adequate compensation mechanisms for all biological effects. Changes that are irreversible and stress the system for long periods of time may constitute a health hazard.

An adverse health effect causes detectable impairment of the health of the exposed individual or of his or her offspring; a biological effect, on the other hand, may or may not result in an adverse health effect.

It is not disputed that electromagnetic fields above certain levels can trigger biological effects. Experiments with healthy volunteers indicate that short-term exposure at the levels present in the environment or in the home do not cause any apparent detrimental effects. Exposures to higher levels that might be harmful are restricted by national and international guidelines. The current debate is centred on whether long-term low level exposure can evoke biological responses and influence people's well being.

The definition by the Institute of Electrical and Electronic Engineers (IEEE)[3], although a little more technical is also useful: 

"Established adverse health effect: A biological effect characterized by a harmful change in health that is supported by consistent findings of that effect in studies published in the peer-reviewed scientific literature, with evidence of the effect being demonstrated by independent laboratories, and where there is consensus
in the scientific community that the effect occurs for the specified exposure condition." versus the biological effect as “alterations of the structure, metabolism, or functions of a whole organism, its organs, tissues, and cells. Biological effects can occur without harming health and can be beneficial. Biological effects also can include adaptive responses."

From these different explanations, we can clearly see that there is an important difference between a biological effect and a health effect, even though many articles do not differentiate between the two – whether it is in relation to EMF or in other contexts. 

So when you are reading the next article, it might be interesting to see whether the authors make the proper distinction between the two, and if they don’t, it may say something important about the quality of the reporting. 


MWF’s “20 years of research” booklet:

WHO’s factsheet “What are electromagnetic fields?”: (accessed 5 September 2018) 

Institute of Electrical and Electronic Engineers Inc (IEEE) IEEE Standard for Safety Levels with Respect to Human Exposure to Radio Frequency Electromagnetic Fields,3 kHz to 300 GHz. IEEE; Piscataway, NJ, USA: 2006.

[1]MWF’s “20 years of research” booklet:
[2]WHO’s factsheet “What are electromagnetic fields?”: (accessed 5 September 2018)
[3]Institute of Electrical and Electronic Engineers Inc (IEEE) IEEE Standard for Safety Levels with Respect to Human Exposure to Radio Frequency Electromagnetic Fields,3 kHz to 300 GHz. IEEE; Piscataway, NJ, USA: 2006.

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