I think the answer to that one is that we don't have a presumptive model of decision-making. As the brigadier-general testified earlier, it's not because you were exposed to something that you necessarily develop something. What we don't have is a system by which it's assumed or presumed that you get something from the actual activity that you've been under. It could be a physical injury or a mental health injury, or it could certainly be something that develops as a result of exposure. There does have to be something that links it from the service perspective.
I understand the question that if there were contaminants at a particular site, and if somebody was there and they have cancer, then isn't that the link that needs to be done? It's not a presumptive model from that point of view, but it is part of the information and the evidence used in decision-making.
The veterans themselves don't have to actually prove, necessarily, that they were at site X, given that it is either identified in Canadian Armed Forces information or identified perhaps even in their service records that they were in a site that was exposed to chemicals of some sort or that they worked in a trade that had them exposed, as I think Mr. Hammerschmidt explained in the first hour. If they were working with vehicles, for example, and were always using the same kinds of chemical products on a regular basis, day-to-day, that could have exposed them, these are all factors in the decision-making process, but they aren't necessarily straight links either.