Do health systems need the precautionary principle

Should the precautionary principle be expanded into the injury and preventative medical fields?

I B Pless from the Montreal Children's Hospital (check www.injuryprevention.com ) calls for expanding the precautionary principle into preventative medicine.

Generally, the medical field relies on epidemiology, where actual events are the basis for further study.  Typically, diseases or injuries arise, and then the causes are determined and preventative measures are put in place to prevent further disease and injury.  Pless comments that maybe we should be using the precautionary principle as a good public health initiative by focusing on primary prevention and a recognition that unforeseen circumstances and unwanted consequences are not unusual with human activities.