1 00:00:01,920 --> 00:00:07,040 Speaker 1: Welcome to brain Stuff production of iHeart Radio. Hey brain Stuff, 2 00:00:07,080 --> 00:00:11,280 Speaker 1: Lauren volgabam Here. The last thing people want in a 3 00:00:11,280 --> 00:00:15,160 Speaker 1: public restroom is more germs, But depending on how they 4 00:00:15,200 --> 00:00:19,040 Speaker 1: wash and dry their hands, that maybe exactly what they're spreading. 5 00:00:20,720 --> 00:00:23,680 Speaker 1: There's a large vein of research studying the effects of 6 00:00:23,760 --> 00:00:27,840 Speaker 1: hand washing, hand drying, and germs, and the results are 7 00:00:28,000 --> 00:00:32,879 Speaker 1: complicated and take. A study published in the journal Applied 8 00:00:32,920 --> 00:00:37,960 Speaker 1: and Environmental Microbiology, the authors found, after studying samples collected 9 00:00:38,000 --> 00:00:41,720 Speaker 1: from both ambient bathroom air and air dryer blown bathroom air, 10 00:00:42,200 --> 00:00:44,720 Speaker 1: and that because hand dryers suck in the air in 11 00:00:44,760 --> 00:00:48,720 Speaker 1: a restroom which is full of constantly circulating microbes and debris, 12 00:00:49,000 --> 00:00:51,479 Speaker 1: and then spew it out at a high velocity, they 13 00:00:51,600 --> 00:00:57,560 Speaker 1: actually expose people to more microbes. The researchers exposed both 14 00:00:57,600 --> 00:01:00,440 Speaker 1: types of air to petree dishes and found out that 15 00:01:00,480 --> 00:01:04,560 Speaker 1: when the hand dryers weren't running, only six bacterial colonies grew, 16 00:01:05,160 --> 00:01:07,520 Speaker 1: but when the dryers were running, the total number of 17 00:01:07,560 --> 00:01:10,360 Speaker 1: colonies grew to as many as sixty per plate, and 18 00:01:10,400 --> 00:01:14,119 Speaker 1: included strains of staff that are capable of causing serious infection. 19 00:01:15,200 --> 00:01:18,000 Speaker 1: Another study published in twenty fifteen in the Journal of 20 00:01:18,040 --> 00:01:22,520 Speaker 1: Applied Microbiology compared different hand drying methods and their effect 21 00:01:22,640 --> 00:01:27,080 Speaker 1: on germ dispersal. The researchers discovered that those vertical jet 22 00:01:27,080 --> 00:01:30,600 Speaker 1: air dryers can actually spread viruses across a distance of 23 00:01:30,640 --> 00:01:34,360 Speaker 1: nearly ten ft or three meters. The jet air dryers 24 00:01:34,360 --> 00:01:37,720 Speaker 1: are activated when a person vertically inserts their hands inside 25 00:01:37,720 --> 00:01:42,120 Speaker 1: the machine, causing powerful air jets to turn on. However, 26 00:01:42,400 --> 00:01:46,000 Speaker 1: the researchers found that these air jets spread viral plaques, 27 00:01:46,280 --> 00:01:48,960 Speaker 1: which are groups of clumped viruses, at a rate of 28 00:01:49,000 --> 00:01:53,000 Speaker 1: one thousand, three hundred times more than paper towels. The 29 00:01:53,000 --> 00:01:56,120 Speaker 1: study did not investigate the distribution of bacteria, which are 30 00:01:56,160 --> 00:02:01,080 Speaker 1: bigger than viruses. The findings were recorded after participants dipped 31 00:02:01,120 --> 00:02:05,520 Speaker 1: gloved hands into a solution with an innocuous virus. Participants 32 00:02:05,560 --> 00:02:08,560 Speaker 1: then shook excess liquid off their gloves and used one 33 00:02:08,600 --> 00:02:12,600 Speaker 1: of three drying methods paper towels, warm air dryers, and 34 00:02:12,880 --> 00:02:16,639 Speaker 1: jet dryers. The researchers then collected air samples at a 35 00:02:16,760 --> 00:02:20,320 Speaker 1: variety of distances from each type of dryer. They also 36 00:02:20,440 --> 00:02:23,560 Speaker 1: used petree dishes to collect viruses that landed on surfaces 37 00:02:23,600 --> 00:02:27,160 Speaker 1: adjacent to the drawing stations. In the end. The jet 38 00:02:27,200 --> 00:02:32,480 Speaker 1: air dryer spread viruses the farthest, so that sounds bad, 39 00:02:33,120 --> 00:02:36,440 Speaker 1: but not so fast, says Dyson, the company that makes 40 00:02:36,520 --> 00:02:40,520 Speaker 1: the popular air Blade jet air dryers. In two thousand eight, 41 00:02:40,600 --> 00:02:43,120 Speaker 1: the Dyson jet air dryer was the first such product 42 00:02:43,200 --> 00:02:46,200 Speaker 1: to earn accreditation from the Royal Society for Public Health. 43 00:02:47,080 --> 00:02:51,600 Speaker 1: Dyson argues that other research from found that upcent of 44 00:02:51,680 --> 00:02:55,320 Speaker 1: fresh yet unused paper towels tested in the US contained 45 00:02:55,320 --> 00:03:00,200 Speaker 1: bacteria which can transfer to hands. Dyson also contends that 46 00:03:00,280 --> 00:03:05,120 Speaker 1: the Journal of Applied Microbiology study artificially inflated germ concentrations. 47 00:03:05,600 --> 00:03:08,800 Speaker 1: In real life situations, the company says most people would 48 00:03:08,800 --> 00:03:11,320 Speaker 1: not have the sheer number of viruses on their hands 49 00:03:11,360 --> 00:03:14,120 Speaker 1: as was used in the study, nor would they stick 50 00:03:14,160 --> 00:03:17,680 Speaker 1: their unwashed, virus coated hands into a jet dryer without 51 00:03:17,800 --> 00:03:22,560 Speaker 1: rinsing and cleaning first. So what's the best course of 52 00:03:22,600 --> 00:03:26,840 Speaker 1: action for hand washers? Even the professionals are debating the issue. 53 00:03:27,320 --> 00:03:30,960 Speaker 1: A study published an Infection Control and Hospital Epidemiology in 54 00:03:32,200 --> 00:03:35,360 Speaker 1: compared the three step handwashing method outlined by the US 55 00:03:35,440 --> 00:03:38,480 Speaker 1: Centers for Disease Control and Prevention or CDC to the 56 00:03:38,560 --> 00:03:42,680 Speaker 1: six step strategy of the World Health organization. The study, 57 00:03:42,760 --> 00:03:45,640 Speaker 1: which observed doctors and nurses using both of these hand 58 00:03:45,640 --> 00:03:48,800 Speaker 1: washing techniques, found the six step method got rid of 59 00:03:48,840 --> 00:03:53,440 Speaker 1: more bacteria. This method includes using an alcohol based hand rub. 60 00:03:54,000 --> 00:03:57,040 Speaker 1: The CDC has since changed the recommendation from the three 61 00:03:57,040 --> 00:04:02,080 Speaker 1: step handwashing process to a five step protocol. The issue 62 00:04:02,120 --> 00:04:05,400 Speaker 1: of compliance when implementing the six step process came up 63 00:04:05,480 --> 00:04:08,200 Speaker 1: during the study, though for the article this episode is 64 00:04:08,200 --> 00:04:11,080 Speaker 1: based on how Stuff Works. Spoke with Jackie Riley, these 65 00:04:11,080 --> 00:04:16,200 Speaker 1: studies lead author. She said only of providers completed the 66 00:04:16,400 --> 00:04:20,479 Speaker 1: entire hand hygiene process, despite participants having instructions on the 67 00:04:20,520 --> 00:04:23,279 Speaker 1: technique in front of them and having their technique observed. 68 00:04:23,839 --> 00:04:28,159 Speaker 1: This warrants for their investigation. Taking all of this into 69 00:04:28,160 --> 00:04:31,400 Speaker 1: consideration for now, I'd say that everyone washing their hands 70 00:04:31,480 --> 00:04:34,480 Speaker 1: properly in the first place is perhaps more important than 71 00:04:34,520 --> 00:04:38,120 Speaker 1: which drying method is used afterwards. As we all learned 72 00:04:38,160 --> 00:04:40,960 Speaker 1: at the beginning of the COVID pandemic, that's wetting your 73 00:04:41,000 --> 00:04:43,840 Speaker 1: hands and rubbing all of your hand surfaces, including the 74 00:04:43,880 --> 00:04:46,840 Speaker 1: fingertips and nails, with soap for at least twenty seconds 75 00:04:46,960 --> 00:04:55,080 Speaker 1: or two rounds of Happy Birthday. Today's episode is based 76 00:04:55,080 --> 00:04:58,120 Speaker 1: on the article Hand jet, hand dryers, really blast out 77 00:04:58,120 --> 00:05:01,000 Speaker 1: a germ cloud? Well, yes and no on how Stuffworks 78 00:05:01,000 --> 00:05:03,800 Speaker 1: dot Com, written by Laurie L. Dove. Brain Stuff is 79 00:05:03,800 --> 00:05:05,800 Speaker 1: production of I Heart Radio in partnership with how stuff 80 00:05:05,839 --> 00:05:08,400 Speaker 1: Works dot Com, and it's produced by Tyler Clang. Four 81 00:05:08,480 --> 00:05:11,320 Speaker 1: more podcasts my heart Radio, visit the I heart Radio app, 82 00:05:11,400 --> 00:05:14,080 Speaker 1: Apple Podcasts, or wherever you listen to your favorite shows.