There seems to be lots of speculation about the Ebola virus becoming airborne. As of right now, there is no evidence that it is being carried by vapor from an infected person’s breath, the way say, flu, a cold, or measles can be spread.
From what I’m seeing, the virus can be spread by larger droplets of saliva if someone is heavily infected. That makes sense, because we’re talking about bodily fluids. The difference seems to be that for Ebola to spread this way, it has to be a noticeable droplet (one that you feel land on your skin), rather than a mist hanging in the air.
Snopes and the Washington Times have a couple of good articles about this. The Washington Times points out that researchers involved in studying the Reston strain of Ebola who found that it can spread between monkeys through the air by saliva droplets under certain circumstances have no evidence the current outbreak is being spread that way. Of course, being good scientists, they can’t rule out the (remote) possibility that the virus could mutate that way, but the evidence doesn’t seem to show it.
If it were actually airborne, we’d see different transmission patterns. Right now, if families take appropriate precautions, and immediately isolate symptomatic patients, no one else gets it. If it were airborne, more of the family members would catch the virus. We would have lots more cases in Monrovia, especially in the densely-populated slums. Studies done in earlier outbreaks in central Africa show that children who were taught not to touch a sick adult did not catch Ebola, even if they lived in the same one-room hut.