The Fate of Mengovirus on Fiberglass Filter of Air Handling Units

Abstract

One of the most important topics that occupy public health problems is the air quality. That is the reason why mechanical ventilation and air handling units (AHU) were imposed by the different governments in the collective or individual buildings. Many buildings create an artificial climate using heating, ventilation, and air-conditioning systems. Among the existing aerosols in the indoor air, we can distinguish the bioaerosol with biological nature such as bacteria, viruses, and fungi. Respiratory viral infections are a major public health issue because they are usually highly infective. We spend about 90% of our time in closed environments such as homes, workplaces, or transport. Some studies have shown that AHU contribute to the spread and transport of viral particles within buildings. The aim of this work is to study the characterization of viral bioaerosols in indoor environments and to understand the fate of mengovirus eukaryote RNA virus on glass fiber filter F7 used in AHU. In this study, a set-up close to reality of AHU system was used. The mengovirus aerosolized was characterized and measured with the electrical low pressure impact and the scanner mobility particle size and detected with RT-qPCR. The results about quantification and the level of infectivity of mengovirus on the filter and in the biosampler showed that mengovirus can pass through the filter and remain infectious upstream and downstream the system. Regarding the virus infectivity on the filter under a constant air flow, mengovirus was remained infectious during 10 h after aerosolization.

Keywords: AHU; Fiberglass filter; Indoor air quality; Mengovirus.

Fig. 1

Description of the experimental set-up (adapted from Forthomme et al. (2012))

Fig. 2

Temperature and relative humidity measured in the system close to the filters during aerosolization

Fig. 3

Particle size distribution of the mengovirus suspension generated by the medical nebulizer measured with the ELPI™ (d(N) = number of particles; dp = particle diameter)

Fig. 4

Particle size distribution of the mengovirus suspension generated by the medical nebulizer measured with the SMPS™ (d(N) = number of particles; dp = particle diameter)

Fig. 5

Detection and quantification of mengovirus on each stage of the ELPI™

Fig. 6

Comparison of infectivity detected and quantification of mengovirus downstream of the system and on the filters

Fig. 7

Effect of time of aerosolization on the infectivity of mengovirus on the filters