LAUSR

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused millions of deaths currently. Mounting effective responses to the pandemic have become top priorities for governments around the world. Laboratory experiments have confirmed for the first time that fumigation with ozone (O3) at low O3 doses (7500–15,000 μg m−3·min) can inhibit the SARS-CoV-2 and inactivate the virus at high O3 doses (129,000 μg m−3·min). The RNA copy number of SARS-CoV-2 significantly decreased (95.9–97.7% reduction) when exposed to O3 at a low concentration of 250 μg m−3 for 30 and 60 min. A significant negative relationship between the numbers of confirmed SARS-CoV-2 cases and ambient O3 in Chinese cities indicated that the spread of SARS-CoV-2 may have been inhibited by high O3. An analysis of data from Chongqing showed that the transmission of COVID-19 increased when the O3 mixing ratios in the air were relatively low, and transmission decreased when O3 increased. Based on these findings, we also propose a new Safety O3 Emission (SOE) method to increase indoor O3 to levels (< 160 μg m−3) that inhibit the transmission of the SARS-CoV-2 but are not harmful for humans. This could serve as timely and low-cost solution for suppressing COVID-19 outbreaks throughout the world.