**6. Dealing with knowledge in risk perception**

Identifying hazard and severity of a damage has direct consequences for risk perception: "Perception is a process by which individuals select, organize and interpret stimuli to generate a coherent and meaningful picture" [16]. In contrast to risk assessment, which can have a scientific basis with a structure and procedures, risk perception is subjective, involves affects and there are many factors that can influence the way a risk is perceived.

Literally, risk cannot be perceived. Therefore, *psychological research* focusing on risk perception explores how judgments about the riskiness of an event, substance, agent, or technology are made in which cognitive, affective, and moral processes are involved. Although the first risk perception studies were conducted more than 50 years ago, the concept of "perceived risk" only began to gain popularity in the mid‐1970s [17]. Slovic's approach known as the psychometric paradigm aims at the "quantitative description of the cognitive and evaluative mental structure of risk and its determinants" [18]. His research focuses on "what people mean when they say that something is (or is not) 'risky', and to determine what factors underlie those perceptions" [19]. It focuses on the beliefs laypersons hold with regard to how chemicals cause health risks. For instance, laypersons are less sensitive to dose‐response relationships compared to toxicologists suggesting that laypersons do not differentiate between the qualitative hazard and the quantitative risk, and therefore do not see risk as something that can be increased or reduced due to interventions or changes in exposure levels. This misconception is a continuing challenge in medical risk communication because most interventions, especially health promoting interventions, reduce but do not eliminate risks. Risk of an adverse event can generally only be reduced, but specific risks related to a certain hazard might be eliminated if the hazard is eliminated, though it may take some time. If you quit smoking, after 20 smokeless years, you will have vascular disease mortality comparable with never smokers [20], but like the rest of the population you still may die of vascular disease because of other hazards leading to the same adverse event.

From the rational point of view, to evaluate a risk, you need to know something about the hazard, assess probabilities as well as consequences of the negative outcome. In fact, however, intuitive risk judgment has a strong affective component, and it is associated with moral concerns and may neglect any probability consideration in risk appraisal. Doing something about your personal risk depends on how you understand the risk. This is a subjective exercise including the compilation of the more objective information on hazard and risk in combination with individual assessments on severity of risk and potential side effects, and last but not least on personal values and preferences.

From the *sociological point* of view, probabilistic risk assessment alone is unsociological. Sociological understanding of risk needs additional social, cultural, and historical contexts. Sociology explains how risks are handled in a society and might thereby clarify potential public misperceptions of risk. When technically defined risks are not contextually generated, public risks understanding will be defined as wrong, if it differs from the factual experts' opinion. From the sociological point of view, it is an error not considering contextual factors like traditions, culture, norms, etc. even though that does not mean that the factual knowledge is wrong. The role of sociology, when it comes to risk, is to explain why errors in dealing with risk in a society occur but not the truth behind them. Implication of this perspective deals with risk communication. The factual knowledge about specific risks needs to be understood and communicated. Sociology emphasizes that when dealing with communication it is important to consider different segments of the public understanding of risks to avoid misperception. Sociological amplification of risk explains how risks and events or accidents interact with psychological, social, institutional, and cultural processes, and often increase or decrease risk perception, public concern, and thereby risk behavior. The objective risk assessment provides information about the risk, but for a sociologist the task is to analyze how this information is understood and reflected in practical social actions in the public. Risks and hazards are sociocultural events and they are not only neutral facts that generate specific signals. It should be considered that also an assessment of a risk can be seen as a construction of a risk and hazard. This implies for sociology to see and explain risk as an overall product of social and cultural processes [21].
