Risk Assessment Principles
Conceptual Basics
In many places throughout this site we talk about risk assessment. The related concepts of hazard, exposure and risk are used repeatedly. For people whose occupation is not risk assessment, the terminology can be confusing. When media professionals use these concepts, at times incorrectly or inappropriately, public fear can easily be raised to levels that are not warranted by the facts. Let us therefore define these concepts up front, and use some examples for clarification.
Risk = Hazard x ExposureHazard
Hazard is the inherent properties of a substance, object or activity with a potential for adverse, or harmful, effects to occur.
For example:
For example:
Exposure
Exposure is a quantitative measurement of the extent to which a given hazard is present. In order for a person to be exposed, the hazard must be present in a particular dimension. In this dimension, the person potentially could be harmed.
Examples of exposure measures are:
Examples of exposure measures are:
Risk
Risk is the probability that an adverse effect will occur to someone. Risk is therefore also quantitative, and can be expressed as a probabilistic number, such as a percentage.