This paper does not specifically address the fate of coronaviruses in water. But it reports some relevant facts that affect the survival of coronaviruses on surfaces. These are the importance of air temperature and relative humidity.
This research was undertaken using surrogate viruses in order to avoid the challenges of working with the highly pathogenic SARS-CoV. Two potential surrogates were evaluated:
- transmissible gastroenteritis virus (TGEV) and
- mouse hepatitis virus (MHV)
These (potential) surrogates were used to study the influence of air temperature and relative humidity on the survival of coronaviruses on stainless steel.
At 4 degrees C, infectious virus persisted for as long as 28 days. Inactivation was more rapid at 20 degrees C than at 4 degrees C, at which the viruses persisted for 5 to 28 days, depending on relative humidity. Both viruses were inactivated more rapidly at 40 degrees C than at 20 degrees C.
The relationship between inactivation and relative humidity was not monotonic, and there was greater survival or a greater protective effect at low relative humidity (20%) and high relative humidity (80%) than at moderate humidity (50%).
The authors concluded that when high numbers of viruses are deposited, TGEV and MHV may survive for days on surfaces at temperature and humidity conditions typical of indoor environments.
They stated that TGEV and MHV could serve as conservative surrogates for modelling exposure, the risk of transmission, and control measures for pathogenic enveloped viruses, such as SARS-CoV.
Casanova LM, Jeon S, Rutala WA, Weber DJ and Sobsey MD (2010) Effects of Air Temperature and Relative Humidity on Coronavirus Survival on Surfaces. Applied and Environmental Microbiology, 76(9), 2712-2717.