I think you named some of the factors there in shift work and in the cumulative effects.
As far as the workplace itself, there are some issues based on traditions within the fire service. It's no different from the police services or the armed forces. You have a service that has relied on traditions and ways of getting through some of those issues that don't necessarily translate too well today. You also have a more diverse work force, which you didn't have.
One of the things we've looked at—and some studies are being done—are gender-based differences in how people deal with some of those types of issues, as well. It may well turn out through the research we get that, based on your gender, there may be better ways to approach debriefings and stress management.