Control of Airborne and Liquid-borne Fungal and Pet Allergens Using Microwave Irradiation

Abstract

In this study, the dog, cat allergens (Can f 1 and Fel d 1) and fungal allergens (Alt a 1 and Asp f 1) were aerosolized and exposed to the microwave irradiation (2450 MHz) at different output powers for up to 2 min. The allergen bioaerosols were collected by a BioSampler, and analyzed using enzyme-linked immunosorbent assay (ELISA). Control and microwave-irradiated Asp f 1 allergens were also tested with IgEs in human blood sera samples. For airborne Asp f 1 and Alt a 1 allergens, the allergenicity was shown to decrease about 50% when exposed to microwave irradiation at 385 and 119 W and relatively no change at 700 W. For airborne Can f 1 allergen, the allergenicity was shown to increase about 70% when exposed to the irradiation at 385 W, but remained relatively unchanged at 700 and 119 W. In contrast, airborne Fel d 1 allergen was observed to lose allergenicity completely at 700 W, and retained about 40% and 80% at 385 and 119 W, respectively. Radioallergosorbent (RAST) tests showed that changes detected in IgE levels in human blood sera mixtures were not statistically significant for the control and microwave-irradiated waterborne Asp f 1 allergens. This study implies that although certain allergenicity reductions were observed for some allergens in certain cases, particular care should be taken when the microwave irradiation is used to disinfect food, water, and air because of its complex effects.

Microwave-induced release and degradation of airborne endotoxins from Escherichia coli bioaerosol

“…The inactivation performance of E. coli. bioaerosol, in this study, can reach 4-log, which is more efficient than that of waterborne exposure to MW irradiation (1-log) under similar experimental conditions [9]. Some other literatures reported higher inactivation performance in liquid phase using longer exposure time (several minutes or hours) and larger input energy [32].…”

“…Many studies have utilized MWs to inactivate microorganisms in liquids [5], solids [6], and food [7]. Only a few studies on airborne microbes have been conducted [8,9].· Hamid et al reported preliminary results of MW on airborne fungi, yeast and bacteria in food processing plants [10]. Zhang et al utilized microwave assisted nanofibrous air filter to disinfect airborne E. coli cells and B. subtilis endospores [11].…”

Airborne disinfection using microwave-based technology: Energy efficient and distinct inactivation mechanism compared with waterborne disinfection

“…Finally, the required energies for 1-log inactivation were calculated as 2.3 J per loginactivation and 116.9 J per log-inactivation for airborne and waterborne bacteria, respectively. Therefore, the results demonstrated the superior energy efficacy for airborne microbes inactivation compared with waterborne microbes (Plazas-Tuttle et al, 2017;Wu & Yao, 2013). (Fig.…”

“…In the electromagnetic field, photons carrying electromagnetic radiant energy are absorbed to inactivate the microorganism (Wu & Yao, 2013;Wu & Yao, 2014). Herein, the detailed derivation process of the relationship between the microbial inactivation and absorbed energy is shown in SI 4(Support Information).…”

“…Many studies have utilized MWs to inactivate microorganisms in solid, liquid, water phases, and a few studies on airborne microbes (Awuah, Ramaswamy, Economides, & Mallikarjunan, 2005;Mainelis et al, 2002;Mawioo, Rweyemamu, Garcia, Hooijmans, & Brdjanovic, 2016;Takashima, Miyakawa, & Kanno, 2007;Wang, Zhang, & Liu, 2018). The application of MW technology for environmental concerns is limited by energy efficiency, because MW energy is primarily converted to heat the media instead of inactivating the microbial cells (Wu & Yao, 2013). However, the comprehensive investigation on the utilization pathway and energy efficiency during MW irradiation has not been conducted yet.…”