Variation in value of annual effective natural gamma dose rate during lockdown in the pandemic situation in various countries

Coronavirus Disease 2019 (COVID-19) has been declared officially as the pandemic worldwide. This novel coronavirus affects almost the whole world and it can quickly spread among the population in several ways. This has initially come from China and within a few months, covers the overall world. Therefore, many countries have decided to restrict the movement through lockdown to control the spreading of COVID-19 novel virus among the population. During this lockdown condition, almost all except few essential people stay at home means staying inside of houses 24 x 7 hours. The study aims to calculate the impact of this lockdown condition on the annual natural gamma radiation dose. The values of indoor gamma radiation are not the same as the outdoor gamma dose rate; the ration between indoor and outdoor gamma dose rates varies based on country to country. In this study, we have used indoor-outdoor gamma dose rate ratio which was reported by UNSCEAR (United Nations Scienti?c Commission on Effects of Atomic Radiation) and calculated the variation of annual dose rate during this pandemic condition that will be helpful for estimation of gamma expose scale for this year of various countries. The higher ratio of indoor and outdoor gamma dose rates showed a high variation in annual dose rate. It was found that the change in annual dose rate continuously increases with respect to the number of days of lockdown. This will also affect much more at high background radiation areas as compared to the low background area.