Efficient trapping and destruction of SARS-CoV-2 using PECO-assisted Molekule air purifiers in the laboratory and real-world settings.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is transmitted human-to-human via aerosols and air-borne droplets. Therefore, capturing and destroying viruses from indoor premises are essential to reduce the probability of human exposure and virus transmission. While the heating, ventilation, and air conditioning (HVAC) systems help in reducing the indoor viral load, a targeted approach is required to effectively remove SARS-CoV-2 from indoor air to address human exposure concerns. The present study demonstrates efficient trapping and destruction of SARS-CoV-2 via nano-enabled filter technology using the UV-A-stimulated photoelectrochemical oxidation (PECO) process. Aerosols containing SARS-CoV-2 were generated by nebulization inside an air-controlled test chamber where an air purifier (Air Mini+) was placed. The study demonstrated the efficient removal of SARS-CoV-2 (99.98 %) from the test chamber in less than two minutes and PECO-assisted destruction (over 99%) on the filtration media in 1 h. Furthermore, in a real-world scenario, the Molekule Air-Pro air purifier removed SARS-CoV-2 (a negative RT-qPCR result post-running the filter device) from the circulating air in a COVID-19 testing facility. Overall, the ability of two FDA-approved class II medical devices, Molekule Air-Mini+ and Air-Pro air purifiers, to remove and destroy SARS-CoV-2 in indoor settings was successfully demonstrated. The study indicates that as the "tripledemic" of COVID-19, influenza, and respiratory syncytial virus (RSV) overwhelm the healthcare facilities in the USA, the use of a portable air filtration device will help contain the spread of the viruses in close door facilities, such as in schools and daycare facilities.

Indoor-air purification by photoelectrochemical oxidation mitigates allergic airway responses to aerosolized cat dander in a murine model.

Portable air purifiers help improve indoor air quality by neutralizing allergens, including animal dander proteins. However, there are limited in-vivo models to assess the efficacy of these devices. Here, we developed a novel animal model of experimental asthma using aerosolized cat dander extract (CDE) exposure and compared the efficacy of select air purification technologies. Mice were exposed to CDE aerosols for 6 weeks in separate custom-built whole-body exposure chambers equipped with either a photoelectrochemical oxidative (PECO) Molekule filtration device (PFD) or a HEPA-assisted air filtration device (HFD) along with positive (a device with no filtration capability) and negative controls. Compared to the positive control group, the CDE-induced airway resistance, and plasma IgE and IL-13 levels were significantly reduced in both air purifier groups. However, PFD mice showed a better attenuation of lung tissue mucous hyperplasia and eosinophilia than HFD and positive control mice, indicating a better efficacy in managing CDE-induced allergic responses. Cat dander protein destruction was evaluated by LCMS proteomic analysis, which revealed the degradation of 2731 unique peptides on PECO media in 1 h. Thus, allergen protein destruction on filtration media enhances air purifier efficacy that could provide relief from allergy responses compared to traditional HEPA-based filtration alone.

Performance evaluation of activated carbon sorbents for indoor air purification during normal and wildfire events.

Volatile organic compounds (VOCs) are a significant class of indoor air pollutants and are known for their adverse effects on health. A common strategy to reduce indoor VOC levels is to use sorbents, including activated carbons (ACs). The amount of activated carbon is critical to achieving a reasonable AC filter lifetime in an air purification device. The study aims to estimate the amount of carbon needed in a typical indoor environment and in a heavy use setting such as during cooking, agriculture field fires, or wildfires. The problem is complex as various types of ACs are used, and the type and concentration of VOCs in the indoor environment also vary in different settings. Therefore, literature data on thermophysical parameters for 45 AC-VOC pairs was used to estimate the required amount of AC under a given set of conditions. The study uses modeling distributions of the footprint of suitable carbon filters for the removal of common VOCs encountered indoors for a period of 30 days. It was found that while 50% of AC-VOC pairs surveyed will require about 190-370 g at low indoor VOCs levels of 0.1-1 µmol/m3(considered a good clean indoor environment), up to 1.1 kg of ACs are needed for a carbon filter to survive 30 days in a typical indoor environment (VOCs levels of 10 µmol/m3). On the other hand, 3-15 kg or more AC will be needed in a filter to survive 30 days during adverse events such as wildfires. The objective of the present study is to aid consumers and businesses in making an informed decision on the type of AC-based indoor air filters that meet their needs. Using this data, an open-access online calculator is being developed to predict the amount of carbon needed in a filter/device at any specific indoor air condition.