One milliLiter of aerosolized Ebola infected blood is capable of infecting 10,000,000 people.
One DROP of aerosolized Ebola infected blood is capable of infecting 500,000 people.
Those are the maximum boundary conditions for Airborne Ebola infection based on USAMRIID's report that an airborne dose of less than 10 Plaque Forming Units [PFU] is capable of creating an infection. Research indicates that one mL of Ebola infected blood often contains on the order of 100,000,000 PFU's.
Of course this begs the question, how much could one sneeze in a room infect?
One milliLiter of Ebola infected blood, at maximum, is capable of infecting a 22,072 Square Foot room to the extent that taking one breath of air from that room would infect a person
One DROP of Ebola infected blood, at maximum, is capable of infecting a 1,104 Square Foot room to the extent that taking one breath of air from that room would infect a person
Unfortunately, According to the US Army's Center for Aerobiological Sciences, Medical Research Institute of Infectious Diseases at Fort Detrick, Maryland:
(1) Ebola has an aerosol stability that is comparable to Influenza-A
(2) Much like Flu, Airborne Ebola transmissions need Winter type conditions to maximize Aerosol infection
"Filoviruses, which are classified as Category A Bioterrorism Agents by the Centers for Disease Control and Prevention (Atlanta, GA), have stability in aerosol form comparable to other lipid containing viruses such as influenza A virus, a low infectious dose by the aerosol route (less than 10 PFU) in NHPs, and case fatality rates as high as ~90% ."
"The mode of acquisition of viral infection in index cases is usually unknown. Secondary transmission of filovirus infection is typically thought to occur by direct contact with infected persons or infected blood or tissues. There is no strong evidence of secondary transmission by the aerosol route in African filovirus outbreaks. However, aerosol transmission is thought to be possible and may occur in conditions of lower temperature and humidity which may not have been factors in outbreaks in warmer climates . At the very least, the potential exists for aerosol transmission, given that virus is detected in bodily secretions, the pulmonary alveolar interstitial cells, and within lung spaces"
In summary:Quite possibly the only thing standing between us and a massive EBOLA outbreak is, Winter Weather and ONE Ebola infected sneeze.
Sources:Preparedness for Prevention of Ebola Virus Disease