Ozbiggles, I imagine it wouldn’t be too hard to model it. You know the pilots flight and duty history. Half life is apparently 3-4 hours. >30% produces serious symptoms. I don’t know the uptake mechanism and numbers, but I’m sure the aeromedical types can model it, at least to decide if it’s a possible cause - in the sense of calculating how big the leak would have had to be. Are we talking pinholes or bigger cracks?