The genome of the organism that produces the world's most lethal toxin has been revealed. This toxin is the major weapon in the genome of Clostridium botulinum: less than two kg is enough to kill every person on the planet.
Tension pneumothorax: The most serious type of pneumothorax, this occurs when the pressure in the pleural space is greater than the atmospheric pressure, either because air becomes trapped in the pleural space or because the entering air is from a positive-pressure mechanical ventilator.
1 Ruptured air blisters. Small air blisters (blebs) can develop on the top of your lung. These blebs sometimes burst â allowing air to leak into the space that surrounds the lungs.  Mechanical ventilation. A severe type of pneumothorax can occur in people who need mechanical assistance to breathe.