Effectiveness of air purifier in reducing the viral load in atmospheric air of room of COVID-19 patients

Abstract This study evaluates the effectiveness of air purifiers in reducing the viral load of SARS-CoV-2 in the atmospheric air of rooms housing COVID-19 patients. Air samples were collected using an air sampler before and after the implementation of air purifiers equipped with high-efficiency particulate air (HEPA) filters. Additionally, swab samples were collected from various filters within the air purifiers to assess viral RNA presence. The results demonstrate the detection of SARS-CoV-2 RNA in particulate matter samples collected before air purification, indicating viral presence in the atmospheric air. Moreover, viral load was inversely correlated with the flow rate of the air sampler, with higher flow rates associated with increased viral load. Swab samples from air purifier filters revealed positive RT-PCR results for both the E-gene and RdRp gene of SARS-CoV-2, highlighting viral retention within the filtration system. Notably, the photo-catalyst oxidation filter demonstrated a reduction in viral RNA presence over time. Following air purification, SARS-CoV-2 RNA was undetectable in samples collected from the PVDF membrane filter at lower flow rates, while positive results were obtained at higher flow rates. These findings underscore the potential of air purifiers in reducing viral load and mitigating airborne transmission within healthcare settings. Further research is warranted to optimize air purification strategies and assess long-term efficacy in controlling viral dissemination.