A Study on the Control of Bio-Aerosol for Prevention of Indoor Aerial Infection Using Antimicrobial Air Filter

Abstract

Some indoor bio-aerosols trigger allergic reactions, including hypersensitivity pneumonitis, allergic rhinitis, and various types of asthma. Moreover, human influenza virus is one of the bio-aerosols that causes significant morbidity and mortality every year worldwide. Although vaccination is the most effective way to address the risk of airborne infection, they are not always feasible, available and practiced. An air cleaning device is effective and efficient in removing indoor bio-aerosols and thereby controlling or eliminating these airborne biological contaminants. An antimicrobial filter is developed and its antimicrobial activities against influenza viruses are measured. An extract from Gingko Biloba L. and Sumac (Rhus Javanica L.) possesses antifungal, antibacterial, and antiviral activities thus this class of natural products is used as an antimicrobial agent in this study. An antimicrobial air filters were prepared by coating the natural agent on polypropylene filter media. The antimicrobial rates of the filter against new influenza (H1N1) virus and A/PuertoRico/8/34 (A/PR/8) virus were greater than 99.9999%. The antimicrobial filters were effective in controlling the bio-aerosols by inhibiting bacterial and viral survival on the filter, thereby preventing secondary contamination of filter from breeding of bio-aerosols. An air cleaning device equipped with the antimicrobial air filter was tested for the inhibition effect on viruses and no virus was detected at the outlet of the purifier. Although the antimicrobial filters are developed and tested only for the inactivation of virus in this study, the filter could be also effective in removing other types of bio-aerosols, such as bacteria, fungi, and allergens. The antimicrobial filter appears to be promising application in air cleaning and biological protection fields.

Recent advances in antimicrobial air filter

“…Pressure drop at various face velocity of various air filters are depicted in Figure 3. As shown in Figure 3, symmetric PP membrane showed a relatively high permeability at lower pressure drop [13]. This is because porous hollow fiber membrane generally has thinner selective layer with lower pore size which provides both high permeability and separation ability.…”

“…In addition, GSE has lower cost than propolis. Lee et al [13] used Gingko Biloba L. and Sumac (Rhus Javanica L.) extracts as antimicrobial agents. Those extracts were used for coating polypropylene filter.…”

“…Depositing nanoparticle of antimicrobial agent onto membrane surface may be conducted by dip-coating [13,36,40,[54][55][56], layer-by-layer coating [44], spray coating [46], nebulization process (aerosol process) [34,37,38,42,48], and electro-spraying [4,43,49]. Illustrations of the methods are shown in Fig.…”

“…Similar to Ag, carbon nanotube (CNT) also induces cell membrane damage followed by cell death [41]. Antibacterial agents from natural product extract may contain flavonoids which have antibacterial activities due to several mechanisms, such as inhibition of DNA gyrase, reduction of cell membrane fluidity, the change of cell permeability, and the damage of cell membrane function [13]. However, considering their effect to organic cell, the antimicrobial agent should be non-toxic for avoiding health issues to human.…”

Application of Electrospun Nonwoven Fibers in Air Filters

“…In the air filter field, the accumulation of pathogens on the membranes can cause a secondary bio-aerosol hazardous source that might infect the user, which can be avoided (at least to some extend) if the air filter shows antimicrobial properties [79]. Additionally, antimicrobial air filters can improve the capturing efficiency of pathogens, which enhances the protection level against hazardous micro-organisms [80,81]. Antimicrobial air filters mostly inhibit the pathogens by two mechanisms: (1) Capturing them by the electrostatic interaction between the antimicrobial agent and the microorganism membrane's charge.…”