Ozone Gas Inhibits SARS-CoV-2 Transmission and Provides Possible Control Measures

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 (O(3)) at low O(3) doses (7500–15,000 μg m(−3)·min) can inhibit the SARS-CoV-2 and inactivate the virus at high O(3) 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 O(3) 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 O(3) in Chinese cities indicated that the spread of SARS-CoV-2 may have been inhibited by high O(3). An analysis of data from Chongqing showed that the transmission of COVID-19 increased when the O(3) mixing ratios in the air were relatively low, and transmission decreased when O(3) increased. Based on these findings, we also propose a new Safety O(3) Emission (SOE) method to increase indoor O(3) 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.