This white paper reviews ultraviolet light as a means of inactivating PRRSV and other swine pathogens in production facilities. UVC is efficacious against PRRSV under controlled conditions. Field performance is reduced by dust fouling of the lamps, by air velocity, and by uneven exposure of the air stream to the light. The paper positions the technology as a complement to filtration rather than a replacement for it.
The gap between controlled efficacy and field performance is the recurring theme across alternatives to mechanical filtration. Ouyang and colleagues in 2023 placed ultraviolet germicidal irradiation and ionization in a category of technologies scaled in industrial and medical settings but not yet standard in animal agriculture, distinct from fibrous filtration, which has the production record behind it. The same review reported an electrostatic precipitator prototype achieving greater than 99 percent PRRSV removal, a controlled result of the same kind.
Dust is the specific reason the gap exists in barn air. A dose delivered to an organism depends on lamp output, on exposure time, and on whether the organism is shielded from the light, and barn air carries a heavy particulate load that fouls surfaces and provides that shielding. That is the same particulate load the carrier particle literature describes as the matrix organisms travel on. For a designer, the practical reading is that ultraviolet treatment inherits a maintenance obligation, and that its performance in a given installation is a function of how well that obligation is met rather than of the specification alone.