# Suffocation in a granular medium

I read of a recent accident in Alberta in which three girls fell into an open bed truck carrying canola seeds and suffocated.

In that situation would it have been possible to keep breathing by using a shirt as a filter to breath through, keeping the seeds out? If so, would you be able to breath indefinitely or would oxygen in the local area run out? Could you keep getting fresh oxygen by staying on the move?

• Hmmm. Well, without any rigorous physical reasoning, but just my 2-bit, offhand opinion, I would say that getting seeds into your lungs is a big hazard so trying to use one's shirt as a filter makes sense. Also, unless fresh air is being forced through the seeds, I would guess that the local air would quickly run out. Not sure how successful it would be to get fresh air by moving about, though, since you would be relying on fresh air in the small spaces between the densely packed seeds and so the actual amount of available air per unit volume in a packed seed bin is probably very small.
– user93237
Oct 15 '15 at 22:36
• @SamuelWeir Right, well, that is the whole problem, whether there would be enough air to breathe between the seeds. Oct 15 '15 at 22:42
• Being in a vat of seeds probably led to some difficulty breathing due to compression. However, this seems more of a biology question than physics. Oct 15 '15 at 23:23
• @KyleKanos Maybe. But, well, according to this, the density of canela seed is $669Kg/m^3$ giving $6556Pa/m$ of pressure difference relative to atmosphere using $\Delta p = \rho gh$. Ie, 6.47% ratio per depth. Sounds not too much compression. Well, at least assuming they haven't sank tooooooooo deep. Oct 16 '15 at 3:17