Inactivation of airborne SARS-Co-V2 using NTP-UVGI hybrid process

Indoor environments such as healthcare centers are known as one of the key centers in the outbreak of viral infectious diseases. In the present study, the pathogenic agents' treatment system (PATS) was designed by the combination of non-thermal plasma (NTP) with the ultraviolet germicidal irradiation (UVGI) processes. Then, the treatment efficiency of PATS was measured for the "SARS-Co-V2." The exhaled air of the confirmed case of "COVID-19" was considered as the viral source of "SARS-Co-V2" and directed to the upstream of PATS. The treatment process was done by passing directed air through two steps of treatment (NTP and UVGI). The treatment efficiency of PATS was measured by sampling at the sampling points (before and after the treatment process). According to the energy emission pattern (corona discharge, UV rays) in the designed system, during two steps, the high efficiency of treatment for the collected pathogens was achieved. Based on the real-time polymerase chain reaction (RT-PCR) results, the CT value was lower than 29 (CTs < 29), and after the treatment using PATS was upper than 40 (CTs > 40) confirming the highest removal efficiency of "SARS-Co-V2." Also, the treatment efficiency of each reactor in individual operation was at the optimum level. The findings suggested, the present PATS may eliminate the viral pathogens with hospital sources and also, be applicable in the other intensive care unit (ICU) wards with the same risk thus, significantly reducing the possible exposure risk of healthcare and sick companions, and preventing the outbreak of infectious diseases.

Occupational exposure of health care personnel to SARS-CoV-2 particles in the intensive care unit of Tehran hospital

The outbreak of SARS-CoV-2 (COVID-19) has attracted much attention to study its possible presence and airborne transmission. The possibility of COVID-19 airborne transmission in indoor environments is debatable. The present study examined the concentration of viral RNA-containing particles produced directly or indirectly by breathing or coughing of confirmed COVID-19 patients or by carriers without symptoms. Some studies do not accept this method of transmission (COVID-19 airborne transmission). The present study aimed to measure the possible exposure of health care personnel to SARS-CoV-2 particles that may have been suspended in the air to respond to the hypothesis of COVID-19 airborne transmission. Airborne particle sampling was performed using impingement method based on NIOSH (chapter BA) and ASHRAE. Selection of sampling sections was in line with the WHO guidelines. The samples were analyzed using RT-PCR technique. Based on the given results, airborne particles of COVID-19 may present in the air and affect the health of hospital personnel. In fact, the analysis of gene expression in ambient conditions and thereby aerosol transmission of SARS-CoV-2 through air is possible and may lead to occupational exposure of health care personnel. Furthermore, it was found that airborne emission of COVID-19 through the breathing zone of patients, particularly in ICU wards with confirmed cases of COVID-19, may be higher than in other ICU wards. Also, the demonstrated results showed that there is a possibility of reaerosolization (reintroduction) of previously airborne SARS-CoV-2 particles into the atmosphere due to health care personnel frequently walking between different wards and stations of ICU.