2021

Author(s): Maher OA, Kamal SA, Newir A, Persson KM

Countries with abundant solar radiation have the potential to invest in simple technologies for deactivation of many bacteria and viruses in medical solid waste. In addition to the traditional Infection and Prevention Control (IPC) measures, these simple technologies contribute to better protection of health care workers in countries with compromised solid management schemes. Monitoring of temperature, relative humidity and ultraviolet inside containers soundly designed to collect disposal infectious waste illustrated to deactivate several viruses and bacteria. Casanova et al., 2010, used some surrogate viruses to overcome the challenges of working with SARS-CoV, concluded that by temperature above 40 °C most of viruses become below levels of detection after 90 min. Here we are proposing a model of a simple transparent container almost 200 L in volume that allow solar energy to be accumulated inside. In summer conditions in the testing site, temperature inside the container reached above 50 °C when the ambient air temperature was around 30 °C. The container was built using epoxy glass to guarantee maximum heat penetration. Actual temperature measurement inside the container was measured in real time against ambient air temperature. We present a mathematical model for predication of maximum temperature at different positions inside the container and their relation to different ambient air temperature scenarios. The mathematical formulas used are based on the conservation laws and a good agreement of a full month of field measurements were obtained. Even in winter conditions in many of developing countries air temperature can maintain levels above 20 °C, which will produce temperature around 30 °C and viruses can reach levels below detection limit in maximum 3 h.

DOI: https://dx.doi.org/10.1016/j.ijheh.2021.113690