Survival of human coronavirus 229E at different temperatures on various food-contact surfaces and food and under simulated digestive conditions.

The COVID-19 pandemic caused by SARS-CoV-2 has had a major impact on human health and the global economy. Various transmission possibilities of SARS-CoV-2 have been proposed, such as the surface of food in the cold chain and food packaging, as well as the fecal-oral route, although person-to-person contact via droplets and aerosols has been confirmed as the main route of transmission. This study evaluated the survivability of HCoV-229E, a SARS-CoV-2 surrogate, in suspension, on food-contact surfaces and on food at various temperatures, and in simulated digestive fluids by TCID50 assay. In suspension, HCoV-229E survived after 5 days at 20 °C with a 3.69 log reduction, after 28 days at 4 °C with a 3.07 log reduction, and after 12 weeks at -20 °C with a 1.18 log reduction. On food-contact surfaces, HCoV-229E was not detected on day 3 on stainless steel (SS), plastic (LDPE), and silicone rubber (SR) at 20 °C with a 3.28, 3.24 and 3.28 log reduction, respectively, and survived after 28 days on SS and LDPE at 4 °C with a 3.13 and 2.88 log reduction, respectively, and survived after 12 weeks on SS, LDPE, and SR at -20 °C with a 1.92, 1.32 and 1.99 log reduction, respectively. On food, HCoV-229E was not detected on day 3 on lettuce and day 4 on chicken breast and salmon at 20 °C with a 3.61, 3.26 and 3.08 log reduction, respectively, and on day 14 on lettuce and day 21 on chicken breast and salmon at 4 °C with a 3.88, 3.44 and 3.56 log reduction, respectively. The virus remained viable for 12 weeks in all foods at -20 °C with 2-2.47 log reduction. In addition, in simulated digestive fluid experiments, HCoV-229E was relatively resistant in simulated salivary fluid (SSF; pH 7, 5), fed state simulated gastric fluid (FeSSGF; pH 3, 5, 7), and fasted state simulated intestinal fluid (FaSSIF; pH 7). However, the virus was less tolerant in fasted state simulated gastric fluid (FaSSGF; pH 1.6) and fed state simulated intestinal fluid (FeSSIF; pH 5). Therefore, this study suggested that HCoV-229E remained infectious on various food-contact surfaces and foods; in particular, it survived longer at lower temperatures and survived depending on the pH of the simulated digestive fluid.

Biophilic Experience-Based Residential Hybrid Framework.

There has been increasing academic interest in biophilic design in response to recent environmental and climate change issues, including the COVID-19 pandemic. However, discussions of the utilization of digital technology in providing universal access to nature, and opportunities to experience more diverse nature, are lacking. This study aimed to compare and analyze major theoretical systems for biophilic experiences in a residential environment, and to propose a hybrid framework that combines physical and digital design techniques for comparison and analysis. This paper discusses framework application strategies in line with scales of residential environments. Based on a systematic literature review, this study integrated and derived key elements of biophilic experience for a better quality of life in a modern residential environment and proposed a hybrid framework and strategy based on this. As a result, a hybrid framework of 15 integrated factors for three biophilic experiences was derived, and various strengths and potential opportunities were identified in terms of application depending on the scales. At the unit scale, it was found that the well-being and health of residents improved; at the building scale, the potential for sustainability was highlighted; at the complex scale, there was a contribution to higher residential competitiveness in multi-dimensional aspects. In particular, the biophilic experience-based hybrid framework in this study provided insights into addressing the weaknesses and threats discussed in the existing biophilic design.