Risk Communication Issues: Lay vs. Scientist Divide

Risks are based on opinions and perceptions.

This means that the definition of risk according to an expert is no more real than the definition of that same risk according to a member of the public; these two definitions are different because they are based on different underlying realities and social constructions. Scientists measure risks, and perform risks assessments, based on objective measures. They multiply the hazard by the magnitude; that is, the severity of the damage multiplied by the extent of the damage. Non-scientists, or the lay public, use more subjective, qualitative criteria to make decisions about risk (11).

Because they measure risks in different ways, communicating about these risks becomes much more difficult. Scientists and lay persons are concerned about different components of the risk and often do not see eye to eye on what factors should be used to make risk-based decisions. The ongoing problem of communication and action regarding radon in homes provides an example of the problems of communication between scientists and members of the public.

Additionally, the distinction between the public and the scientists is sometimes blurred. Scientists bring in value judgements when facing a risk, and citizens organize groups and create or bring to bear expertise and outside science (12). This can be seen in citizens' advocacy groups that arise out of contamination in their communities; these groups become "experts" in their own right, either because they need to have the scientific literacy and vocabulary to gain credibility with the official experts, because they want to be sure that they are included in the decision-making process, or because they do not trust the official "experts." This can be seen in the concept of popular epidemiology.

Examples of community-driven expertise:

• the community group in the Woburn, MA contamination with TCE
• the activist group at Love Canal dealing with dioxin and other toxins (13).

Public: But I still think it's risky for my baby to be exposed to this chemical that way.

Example 2
Public: These Japanese maples and purple loosestrife look so nice in my garden!

Scientist: But invasive species such as those are a real threat to biodiversity and the preservation of existing native species.