DHS officials say sunlight, heat and humidity may have a “powerful” impact on killing the coronavirus within seconds.William Bryan, science and technology adviser to the Department of Homeland Security, told reporters at the White House on Thursday that government scientists found ultraviolet rays had a potent impact on the pathogen, offering hope its spread may ease over the summer.“The virus dies quickest in the presence of direct sunlight,” Bryan said.“Our most striking observation to date is the powerful effect that solar light appears to have on killing the virus – both surfaces and in the air,” he added. “We’ve seen a similar effect with both temperature and humidity as well, where increasing the temperature and humidity or both is generally less favorable to the virus.”It has long been known that ultraviolet light has a sterilizing effect, because the radiation damages the virus’s genetic material and its ability to replicate.According to U.S. officials, an experiment shows UV rays destroy COVID-19 both on surfaces and in air. And coronavirus dies the fastest when exposed to direct sunlight, although the study cited has not yet been made public and awaits external evaluation.But coronavirus has also proven lethal in warm-weather places such as Singapore, Malaysia, and Thailand, raising broader questions about the impact of environmental factors.Bryan warned it would be “irresponsible” to say the warmer summer months will eliminate the virus. But he said that time period would provide an “opportunity to get ahead” of the pandemic.A key question will be what the intensity and wavelength of the UV light used in the experiment was, and whether this accurately mimics natural light conditions in summer.Past studies have not found reliable evidence that warmer temperatures and the higher humidity of spring and summer will help tamp down the spread of the virus.Bryan shared a slide summarizing the major findings of an experiment carried out at the National Biodefense Analysis and Countermeasures Center in Maryland.On nonporous surfaces such as stainless steel, the new coronavirus takes 18 hours to lose half its strength in a dark, low-humidity environment, Bryan said.In a high-humidity environment, that half-life dropped to six hours, and when the virus was exposed to high humidity and sunlight, the half-life dropped to two minutes, he said.Researchers found a similar effect with the coronavirus that was suspended in the air – simulating the coughing or sneezing that often spreads the disease. In a dark room, the virus maintained half its strength for an hour.But when exposed to sunlight, it lost half its strength in 90 seconds, Bryan said.Researchers also found that isopropyl alcohol was a more effective disinfectant than bleach, he added.
Matt Karatsu | Daily TrojanThe women’s volleyball team had its five-match win streak snapped this weekend, falling to Arizona on Friday, but USC rebounded with a win at Arizona State on Saturday to raise its overall record to 13-4 (5-1 Pac-12).The No. 15 Women of Troy had a tough day in Tucson, Ariz., getting swept 3-0 by the Wildcats at the McKale Center. Sophomore outside hitter Khalia Lanier spearheaded the Trojan attack with nine kills and three service aces, and junior libero Victoria Garrick led the way defensively, tallying 15 digs. However, USC only hit .140 in the match compared to Arizona’s .262 mark, and the team committed 20 errors to the Wildcats’ 14. The Trojans’ sloppy play cost them their perfect conference record, as they suffered their first loss of the season in Pac-12 play.They fared better the next day when the Women of Troy traveled to Tempe, Ariz. to face the Sun Devils. It looked like the team’s rough weekend would continue when USC committed 16 total errors to hand ASU the opening set, 25-19, but head coach Mick Haley’s squad rallied to take three consecutive sets and win the match 3-1.The turnaround came thanks to much-improved efficiency. The Women of Troy nearly doubled their hitting percentage from the previous night against Arizona, recording a .265 mark versus ASU. Senior opposite hitter Brittany Abercrombie, the reigning back-to-back Pac-12 Offensive Player of the Week, matched her career high in kills (18), and senior opposite hitter Niki Withers set a new season best with 15 kills — including seven in the decisive fourth set, when Withers led USC’s comeback from a 4-point deficit.Senior middle blocker Danielle Geiger added 11 kills for her season high — and her best mark since joining the Women of Troy from UC Irvine this fall. Senior setter Reni Meyer-Whalley also recorded her sixth double-double of the year against ASU with 31 assists and 11 digs. The win over the Sun Devils kept USC in second in the Pac-12 standings: The team’s 5-1 conference record puts them just behind 5-0 Stanford.The Women of Troy return home for their next match, as they host Cal at the Galen Center on Friday. Despite being a middling 2-3 in Pac-12 play, the Bears sport an impressive 11-5 overall record. USC swept Cal 3-0 in Berkeley last season, and the team will look to repeat that feat this week.