One danger of a low-head dam, as opposed to a natural rapids or falls, is that the boil-line extends uniformly across it's face. If you were stuck in a recirculating "hole" in a natural rapids, it's possible that you could swim out to the side to escape. At a low-head dam there is no escape. You may be repeatedly pushed under until you become weak and drown, or you may simply be held against the face of the dam. If you were smart you'd be wearing your PFD. If you were smart you would have avoided the dam!
See http://wiki.answers.com/Q/Why_is_getting_caught_in_a_backroller_near_a_low_head_dam_dangerous
One danger of a low-head dam, as opposed to a natural rapids or falls, is that the boil-line extends uniformly across it's face. If you were stuck in a recirculating "hole" in a natural rapids, it's possible that you could swim out to the side to escape. At a low-head dam there is no escape. You may be repeatedly pushed under until you become weak and drown, or you may simply be held against the face of the dam. If you were smart you'd be wearing your PFD.
rip current.
What are the types of biological hazard should be of the greatest concern to food establishment managers? Why?
disease
False. The greatest hazard comes from pyroclastic flows.
Bacteria. The hazard is reduced by keeping food cold.
Bacteria. The hazard is reduced by keeping food cold.
shipping
Bacteria. The hazard is reduced by keeping food cold.
orbital debris.
protons from the Sun
bacteria
It is equal to the risk level of the hazard with the greatest residual risk