Survivability, Temperature, and Filtration
The rapid spread of COVID-19 has urged scientists to discover all the ways in which the virus be transmitted. The hope is that understanding its transmission will enable us to limit its spread.
Viruses can be transmitted through air, human contact, and food. COVID-19 is mainly spread through person-to-person contact. Respiratory droplets spread when an infected person coughs, sneezes, or talks. These droplets can go onto the floor, food, grocery bags, and clothes.
Scientists have researched how long virus droplets can live on each of these surfaces. They have also examined how well a virus can live in water and for how long.
Source: Water, sanitation, hygiene and waste management for COVID-19
Scientists wanted to test how long viruses could live in a variety of water samples. Water samples were collected from laboratory faucets. Some samples were filtered and some were left unfiltered. The samples were also split between room temperature (23 degrees) and cold temperature (4 degrees).
They grew viruses in cells and mixed viruses with tap water. They measured how many days it took for the viruses to be significantly reduced in the combined samples.
Virus Survival in Water Study Setup
First, researchers grew viruses in cells, then extracted and purified the viruses.
2.Add to Water
Researchers collected tap water and mixed in the viruses that they grew.
3. Measure Viral Load
Researchers measured the amount of viruses in the water at days 1, 3, 6, 10, 15, and 21.
Viruses and water temperature
At room temperature, it required only 10 days for coronavirus to almost completely inactivate in filtered water. In cold water, coronavirus could last over a hundred days.
Viruses vs. Water Temperature
Temperature & Viral Survival
Room Temperature - 10 Days
Coronavirus took 7 days to reach a 99.9% reduction in viral load in water at room temperature, and 200+ days to reach this at 40 degrees.
Virus in Filtered Water
All viruses survived longer in previously filtered water, compared to unfiltered tap water.
Viruses vs. Water Filtration
Viral Survival in Filtered Water
Viruses are less likely to survive in filtered water compared to unfiltered tap water. The data measures the number of days it will take to reach a 99.9% reduction in viral load under each condition.
Coronavirus vs Poliovirus
Polioviruses survived much longer than coronavirus in water, with traces living upwards of 71 days at room temperature. Polioviruses survived six times longer than coronavirus at room temperature.
These findings tell us that coronaviruses are much more likely to be inactivated by water than other viruses. It tells us that coronaviruses are more sensitive to water temperature as well.
What does the CDC say?
The CDC doesn’t want us to worry about COVID-19 in our water. Standard treatment methods used by our water systems should remove and inactive the virus.
There is no evidence that COVID-19 lives in pools, hot tubs, spas, or water play areas. Again, proper water-related maintenance should eliminate any viruses.