PRELIMINARY results from U.S. government lab experiments show that the coronavirus does not survive long in high temperatures and high humidity, and is quickly destroyed by sunlight, providing evidence from controlled tests of what scientists believed — but had not yet proved — to be true.

A briefing on the preliminary results offers hope that summertime may offer conditions less hospitable for the virus, though experts caution it will by no means eliminate, or even necessarily decrease, new cases of COVID-19, the disease caused by the coronavirus.

The study found that the risk of “transmission from surfaces outdoors is lower during daylight” and under higher temperature and humidity conditions. “Sunlight destroys the virus quickly,” reads the briefing.

While that may provide some good news about the outlook for outdoor activities, the U.S. Department of Homeland Security briefing on the results cautions that enclosed areas with low humidity, such as airplane cabins, “may require additional care to minimize risk of transmission.”

The results are contained in a briefing by the DHS science and technology directorate, which describes experiments conducted by the National Biodefense Analysis and Countermeasures Center, a lab created after the 9/11 terrorist attacks to address biological threats.

While the DHS describes the results as preliminary, they may eventually make their way into specific recommendations. “Outdoor daytime environments are lower risk for transmission,” the briefing states.

Simulated sunlight “rapidly killed the virus in aerosols,” the briefing says, while without that treatment, “no significant loss of virus was detected in 60 minutes.”

The tests were performed on viral particles suspended in saliva. They were done indoors in environments meant to mimic various weather conditions.

While the lab results are new, scientists for many weeks have predicted, based on available data on the disease’s spread, that warmer, wetter climates would be less hospitable to the spread of the coronavirus.

An early analysis by scientists observed that the virus was spreading more slowly in countries with warmer climates.

But the pandemic may not go away completely in summer, experts warn. Colds and flus don’t disappear in the summer, even if they are less common, they say.

(SD-Agencies)