A recent study done in the United States has found that simulated sunlight can kill SARS CoV-2 on surfaces in 7 to 14 minutes.
The study was led by Shanna Ratnesar-Shumate from the National Biodefense Analysis and Countermeasures Center. The research assumes significance as it was found that the deadly virus could stay on surfaces.
The researchers noted that simulated sunlight was capable of rapidly inactivating the SARS CoV-2 on the stainless steel coupons. Results showed that 90 percent of the infectious virus was inactivated in just 6.8 minutes in saliva solution and every 14.3 minutes in a culture media. The sunlight required for this is similar to the summer solstice seen at 40oN latitude at sea level on a clear day, wrote the researchers. They added that similar inactivation was also seen at a slower rate when levels of sunlight were lower.
Earlier studies have shown that UVC light (absent in natural sunlight) could inactivate coronaviruses. This is the first time that the study has shown that that UVB levels found in natural sunlight can actually inactivate SARS CoV-2 on surfaces, “specifically virus dried on stainless steel coupons.”
“The present study provides the first evidence that sunlight may rapidly inactivate SARS-CoV-2 on surfaces, suggesting that persistence, and subsequently exposure risk, may vary significantly between indoor and outdoor environments. Additionally, these data indicate that natural sunlight may be effective as a disinfectant for contaminated non-porous materials,” said the study.