ABSTRACT
Small air ions have the ability to charge airborne particles, thereby increasing their accumulation on surfaces. Indoor air purification by applying ionization uses electrostatic particle deposition. Respiratory pathogens, including viruses and respiratory droplets carrying viruses or other pathogens, represent bioaerosols, whose particle size distributions contain increasingly larger proportion of fine and ultrafine particles, as the evaporation process proceeds. We have generated two model aerosols: the nebulized NaCl solution, resembling human saliva, and the cigarette smoke, having relatively low water content. We have conducted real life experiments of such surrogate aerosol particle deposition without ionization, using bipolar ionization, as well as using unipolar negative air ions. Particle number concentrations have been measured in the 10 nm–10 μm particle size range. The calculated deposition rates and aerosol particle half-life times were correlated with bioaerosol pathogens based on the core pathogen sizes. Bipolar ionizers emitting equal concentrations of positive and negative ions had low impact to the particle concentration decrease. Intense negative air ionization resulted in pronounced deposition rate increases, particularly in the particle size range of viruses including the SARS-CoV-2. The impact of negative air ionization was most pronounced in the same size range where the deposition rates without ionization were the lowest. Therefore, the results are very promising from the standpoint of air purification and bioaerosol pathogen removal, bearing in mind that the effect of ions will be most pronounced if the unipolar ion rich air stream is directed towards the breathing zone.
ABSTRACT
Introduction/Objective The purpose of the current Echocardiographic Society of Serbia (ECHOS) survey was to assess echocardiography practice in Serbia during the Coronavirus disease 2019 (COVID-19) pandemic. Methods An online survey consisting of 12 questions about the usa of echocardiography, the availability of portable ultrasound devices and personal protective equipment (PPE) was sent to all ECHOS members. Results Overall, 126 ECHOS members (43%) answered the survey. One-third of respondents (36%) were physicians from specialized COVID-19 centers. During the pandemic, indications for echocardiographic examination were restricted in both COVID-19 and non-COVID-19 centers. In COVID-19 centers, 41% of respondents performed lung ultrasound to each patient versus 26% in non-COVID-19 centers. Transesophageal echocardiography was not performed in suspected or confirmed COVID-19 cases in any center. Portable ultrasound devices were available to 66% of respondents from COVID-19 versus 44% of respondents from non-COVID-19 centers (p = 0.018). The respondents reported regular use of PPE, regardless of the patient's COVID-19 status and found their personal knowledge about protective measures and use of PPE satisfactory. Conclusion During the COVID-19 pandemic in Serbia, indications for echocardiography were restricted to clinical scenarios in which the results of examination were expected to alter patient management. In both COVID-19 and non-COVID-19 centers, the use of PPE was in line with national and international recommendations. A wider availability of portable ultrasound devices and application of lung ultrasound could improve patient management in similar situations in the future.