Risks or threats which are not taken seriously may nonetheless be real. Underestimating the consequences of any risk can lead to dangerous situations.
Risk perception fascinates psychologists, but infuriates those concerned with making the world a safer place. There are often large discrepancies between the risk experts worried about and those lay people were most concerned about. Thus radiation from nuclear power plants is probably feared too much by lay people whereas radon seeping into basements or X-rays are probably feared too little. Although people in rich countries live longer than ever, they are more fearful than their ancestors were about threats to their health from the world around them. One reason is mistrust of technology; another is mistrust of scientists, who have too often claimed that a process or substance is safe, and then changed their minds.
The beginning of the 1993 school year was delayed in some New York City schools because some parents were distressed to hear that in some schools asbestos was flaking and exposed. This despite public health officials explaining that the risk of dying from exposure to asbestos was less than the likelihood of getting hit by lightning and that the children were probably at greater risk from playing in the streets during the week the schools were closed to fix the asbestos.
It is not clear that knowledge or ignorance of technical facts drives risk estimation, or that risk estimation is the central factor in public risk perception. It is even less clear whether providing citizens with technical risk information will alter their perceptions of risk or their views of how well government agencies are protecting the environment.