Effect of simulated solar radiation and sodium fluorescein on the recovery of Venezuelan equine encephalomyelitis virus from aerosols.

Almost 90% of the Trinidad strain of Venezuelan equine encephalomyelitis (VEE) virus survived for 1 hr after aerosolization into a dark environment at 30% relative humidity (RH), and 78% survived for 1 hr at 60% RH. After exposure to simulated solar radiation (584 mcal per cm(2) per min) 0.02% of the aerosolized virus survived for 1 hr at 30% RH and 0.006% survived for 1 hr at 60% RH. When 1.0 mg of sodium fluorescein per ml was added to suspensions prior to aerosol dissemination (to determine physical loss of aerosol), no virus was detected after 30 min at either RH upon irradiation. Sodium fluorescein also exhibited some toxicity (31% survival at 60 min) for nonirradiated aerosols of VEE virus at 60% RH; no effect was noted at 30%.