**Preface to "Environmental, Health and Economic Conditions during the COVID-19 Pandemic"**

The spread of coronavirus disease 2019 (COVID-19), which started at the end of 2019, has evolved as a global pandemic. Since the start of the pandemic, COVID-19 has overwhelmed health systems worldwide, from crippling health resources to causing paradigms shifts in healthcare delivery. The various strategies taken to control viral transmission including testing process, quarantine, and isolation have had dire psychological and financial implications on individuals and institutions. Furthermore, many countries have implemented lockdowns and other restrictions to curb the virus's spread resulted in disrupted formal education, unplanned fiscal costs on emergency reliefs, and decreased productivity. Although these strategies to control viral transmission are widely debated, the relative success of these strategies may depend on the concerted multi-sectoral efforts of public health agencies across all level in a coordinated manner. Although the costs of enforcing these control measures are enormous, the ongoing pandemic may have some indirect positive impacts. Among them, locking down cities has brought a sudden drop in air pollution and carbon emissions. These declines are mainly due to the close-down of transport, constructional works, and industrial activities. The purpose of this Special Issue is to explore the environmental, health, and economic dimensions of the effect of COVID-19, considering the multiple interactions between atmospheric emissions, outdoor and indoor air quality, and health and economic conditions. In this context, the most important issues in need of discussion are risk factors for transmission, disease severity, and COVID-19 related deaths, effects of urban environments on the transmission and fatality of COVID-19, impact of COVID-19 on health and economic outcomes, and impact of COVID-19 control measure on air quality.

> **Dirga Kumar Lamichhane** *Editor*
