Kwon KT, et al. J Korean Med Sci. 2020 Feb;35(11):e123. https://doi.org/10.3346/jkms.2020.35.e123

Data on the filtration efficacies of various masks against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are limited. We thus evaluate the effectiveness of the surgical mask, the N95...

Background: Recently, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission through exposure to aerosols has been suggested. Therefore, we investigated the possibility of aerosol SARS-CoV-2 transmission within an apartment complex where residents reported testing positive for SARS-CoV-2 despite having no direct contact with other SARS-CoV-2–infected people. Methods: Information on symptom onset and exposure history of the patients was collected by global positioning system (GPS) tracking to investigate possible points of contact or spread. Samples collected from patients and from various areas of the complex were analyzed using RNA sequencing. Phylogenetic analysis was also performed. Results: Of 19 people with confirmed SARS-CoV-2 infection, 5 reported no direct contact with other residents and were from apartments in the same vertical line. Eight environmental samples tested positive for the virus. Phylogenetic analyses revealed that 3 of the positive cases and 1 environmental sample belonged to the B.1.497 lineage. Additionally, 3 clinical specimens and 1 environmental sample from each floor of the complex had the same amino acid substitution in the ORF1ab region. Conclusions: SARS-CoV-2 transmission possibly occurs between different floors of an apartment building through aerosol transmission via nonfunctioning drain traps.

Historical and ongoing pedestrian anxiety about night crimes in alleyways is an important issue in our society. Therefore, recommended illuminance levels in pedestrian alleys have been established and security lighting meeting such illuminance levels has been installed to ensure proper brightness. However, pedestrians may still feel that such areas are too dark and want to ensure their safety through sufficient brightness, especially late at night. In this study, a smart security lighting system, which was namely the Connected Security Lighting System (CSLS), has been designed to reduce the pedestrians’ fear of crime in smart cities. The CSLS increases the brightness of security lighting by turning on additional lights to relax pedestrians’ psychological fear of crime because of the increased sense of surveillance. Such a change may also deter potential offenders. The CSLS employs various sensors and information communication technologies that are widely used in interior and outdoor smart lighting applications. It also uses a beacon device and smartphone application to effectively detect pedestrians while infrared sensors in the CSLS are activated to detect any pedestrians approaching from the opposite direction after the beacon device is initiated. The method for controlling the CSLS is described and a prototype system is presented to demonstrate the feasibility of this security lighting system in smart cities.