DHS calculators for how long COVID-19 is in air and surfaces
The Department of Homeland Security’s Science and Technology Branch has developed online calculators to estimate how long the coronavirus will stay on surfaces and in the air based on weather conditions.
The surface decomposition calculator estimates the half-life of the virus based on temperature and relative humidity. It also explains when 99.99% of the virus will be rotten.
“This will calculate the half-life of the virus and now it’s very important because the half-life of the virus quite frankly means that if 1000 pieces of the virus are deposited on a surface, the half-life means in that certain period of time. As the calculator tells you, half will be rotten in that time, ”Acting Under Secretary William Bryan told WGNO.
The Airborne Decomposition Calculator estimates half-life based on UV Index, relative humidity, and temperature.
“Sunlight has a huge impact on the breakdown of the virus,” Bryan told WGNO.
The Centers for Disease Control and Prevention has published a guide to how the virus is spread and says it is mostly done through person-to-person contact and rarely through contact with surfaces.
“It is possible that a person will contract COVID-19 by touching a surface or object that has the virus on it and then touching their mouth, nose or maybe eyes,” the CDC said. “This is not thought to be the primary mode of spread of the virus, but we are still learning more about this virus. “
The CDC recommends that everyone wash their hands and “regularly clean and disinfect frequently touched surfaces.”
A study done at the Rocky Mountain Lab at the National Institutes of Health shows that COVID-19 can be detected for hours in the air and up to three days on some surfaces. Scientists tested how long the virus was present, but did not determine if it remained infectious.
Researchers used a nebulizer to put COVID-19 in the air and measured how long it was detectable, according to the study.
They found the virus was detectable for up to three hours in air, up to 24 hours on cardboard, up to four hours on copper, and up to two to three days on stainless steel and plastic.
Another study, titled “Estimating Coronavirus Inactivation by Solar Radiation,” found that 34 minutes of sunshine in summer at noon can inactivate 90% or more of the COVID-19 virus.
The authors wrote that the virus “is expected to be inactivated relatively quickly during the summer in many populated cities around the world.”
Cory Merow, co-author of the “Seasonality and Uncertainty in COVID-19 Growth Rates” study, told the New York Times that although coronavirus cases declined during the summer – which is not currently happening – Public health measures, such as social distancing and wearing masks, would still be needed to stay safe.
Another study by researchers at the Massachusetts Institute of Technology found that it was “extremely unlikely that the spread of 2019-nCoV would slow in the United States or Europe, due to environmental factors.”
The United States hit a record high in daily confirmed cases of the coronavirus on June 24 – with 38,115 new infections – just days after the start of summer, according to the Washington Post.
The coronavirus has infected more than 2 million people in the United States as of June 26 and killed more than 124,000 people nationwide, according to Johns Hopkins University.