How do precautionary measures affect risk perception?

Possible adverse health effects due to electromagnetic fields (EMF) from cellular phones and base stations present a major public health issue across Europe. As scientists cannot exclude that EMF may cause health problems, the application of the precautionary principle is debated heavily. By considering precautionary measures, political decision makers hope to cope with public fears about EMF. Results from two experimental studies indicate that precautionary measures may trigger concerns and amplify EMF-related risk perceptions and may lower trust in public health protection. Such impacts, questioning common expectations, should be considered in decisions about precautionary measures.

Wiedemann, P. M.; Schütz, H.
The Precautionary Principle and Risk Perception: Experimental Studies in the EMF Area
Environmental Health Perspectives, 113 (2005), 4, 402 - 405

How does the public understand SAR values of mobile phones?

The specific absorption rate (SAR) is a prominent topic in the discussion about precautionary health protection. An experimental study investigated the effect of information about various SAR-values (below the existing partial-body limit value of 2 W/kg) on safety judgments of potential mobile phones users.
It turns out that about 94% of the participants do not know the SAR-value of their own mobile phone. SAR-values below existing limits are not perceived as equally safe. Rather, the lower the SAR-value, the higher is perceived safety. However, a majority of the participants does not consider these SAR-values 100 percent safe, even if they are clearly below the existing limits. Explicitly indicating a precautionary limit value (referring to the Federal Office for Radiation Protection or to consumer organizations) does not change this safety evaluation. As expected, safety evaluation of the SAR-values is also related to the perception of mobile phone risks. Those who are concerned about mobile phone communication give lower safety judgments than the unconcerned - independent of the level of the SAR-values.
Irrespective of that, our results suggest that establishing the SAR value as a criterion for mobile phones depends first of all on making it known to the public.

Wiedemann, P. M.; Schütz, H.; Sachse, K.; Jungermann, H.
SAR-Werte von Mobiltelefonen: Sicherheitswahrnehmung und Risikobewertung
Jülich, Forschungszentrum Jülich, Programmgruppe Mensch, Umwelt, Technik, 2005; Arbeiten zur Risiko-Kommunikation ; 89