Practical approach to prevent COVID-19 infection at breast cancer screening.

BACKGROUND: The novel coronavirus disease 2019 (COVID-19) undermines the benefits of cancer screening. To date, no study has identified specific infection control methods. We aimed to provide practical methods for COVID-19 risk reduction during breast cancer screening mammography (MMG) by examining an overview of potential contamination routes of aerosols and possible risks for patients and health care providers. METHODS: Computational fluid dynamics (CFD) simulations were conducted for airflow and aerosol dispersion in a 3D virtual model of a mobile MMG laboratory room. This model was constructed based on the actual mobile screening MMG bus 'Cosmos' in the Chiba Foundation for Health Promotion & Disease Prevention. Examiner and patient geometries were obtained by scanning an actual human using a 3D Scanner. Contamination of the room was evaluated by counting the numbers of suspended and deposited aerosols. RESULTS: We applied the CFD simulation model to the exhalation of small or large aerosols from a patient and examiner in the MMG laboratory. Only 14.5% and 54.5% of large and small aerosols, respectively, were discharged out of the room with two doors open. In contrast, the proportion of large and small aerosols discharged out of the room increased to 96.6% and 97.9%, respectively, with the addition of forced gentle wind by the blower fan. This simulation was verified by a mist aerosol experiment conducted in the mobile MMG laboratory. CONCLUSION: Adding forced ventilation to a MMG laboratory with two doors open may enable risk reduction dramatically. This could be applied to other clinical situations.

Storage system problems in the workplace--case studies of the workplaces in Tokyo and Fukuoka.

The results of a survey that was carried out inside five account division workplaces of design companies in Tokyo and Fukuoka in order to identify problems concerning the personal storage system revealed that the main problem concerns how to organize the files within a desk. Firstly, there is a lack of available storage space and therefore a person couldn't work and sit well as the documents are piled up on the desktop and under the desk. Secondly, the files display within a desk is not sufficient to enable a worker to get what he/she needs easily. Hence, with purpose of overcoming the previous problems, we focused on three requirements: a) How to increase the personal storage space; b) How to display the documents well; and c) How to distribute the documents within a desk. We suggested a solution for each mentioned requirement. This study aims mainly to test the recommended solutions in order to examine their effectiveness to overcome those problems. The results of the tests that were conducted with 20 persons in a working area revealed that the files organization through the desk space has influences on the person's comfort and the time for file accessibility.