Factors of perception

A particularly effective approach in understanding how the perception of risk is shaped is offered by Peter Sandman website. He has made clear that “outrage, not hazard, determines the outcome of risk controversies. Companies and governments are of course obliged to manage the hazard properly, but to cope with the controversy they need to manage the outrage properly as well.”


is the basis for the development of the analysis we propose in this site.

The researches and experience of risk communicators have brought to evidence the different factors that intervene in the formation of outrage.

Trustworthy sources: if the sources of information about the risk is not trusted by the actors to whom the information is addressed, the resentment increases and data are not trusted. The disbelief, or on the contrary the reliance, are a founding element of hazard perception, or of the lack of it.

Voluntary risk: it has been amply demonstrated that to risks which are assumed voluntarily it is associated the perception of a low risk; actually often these are not even included among risks: smoking, driving, mountain climbing, are only a few of the possible examples. The siting of a waste incinerator in a territory has a strong impact on the image of the area and, if the decision making process has not been shared, the decision then clashes with citizens’ voluntary choices that did not foresee their territory as characterised by that plant.

Uncertainty: making decisions under conditions of incertitude is inevitable: many times a day, every day, for each of us. A high incertitude is associated to the calculation of the numerical value of risk, as oit is for every modelling method. This is due, for instance, to the only partial capability of models to describe the diffusion of the substances in the environmental media, or to the incertitude associated with the transfer of the toxicological results of laboratory data and experiments to humans or to the uncertainty of epidemiological statistical analysis. The discussion about the incertitude of the forecasts should be dealt between experts and non-experts by distinguishing the elements of estimates that are rather certain form those that are highly uncertain: for each case study, this requires an open discussion on the available data and the comparison of the risk analysis practices existing either nationally and internationally, to understand what is known about similar events. It is also necessary to explain the method by which the analysis of incertitude has been performed, which sensitivity analysis have been formulated and tested to support the numerical value obtained; it is the responsibility of the risk assessor and of controlling agencies personnel to provide full transparency over the parameters, equations and models that have been used in the numerical value calculation. But we also would like to stress that (rightly so) risk analysis models are based on highly precautionary assumptions: both in the equations used to estimate exposure and in the toxicological assumptions.

Individually controlled: even though it seems difficult to share control among so different actors, such as the managers of a wastes thermal treatment plant and the areas’ residents, experiecne speaks clearly: one cannot keep all control for oneself and at the same time reassure others.

For a complete description of the elements that contribute to increase or reduce risk perception, I suggest reading this list 12 OUTRAGE components and connected documentation.

An in depth analysis of risk perception by workers of a chemical industry is given in the study  La condizione dei lavoratori nello stabilimento chimico di Pieve Vergonte nella storia (1015 -2012) (in italian ‘The condition of workers in the chemical plant of Pieve Vergonte in hystory (1915 -2012)’).