1 00:00:01,920 --> 00:00:06,480 Speaker 1: Welcome to brain Stuff production of I Heart Radio. Hey 2 00:00:06,559 --> 00:00:09,879 Speaker 1: brain Stuff, Lauren Bogle Bomb here Today we're kicking off 3 00:00:10,000 --> 00:00:13,480 Speaker 1: mini series of health and safety topics surrounding the novel 4 00:00:13,520 --> 00:00:18,200 Speaker 1: type of coronavirus identified in which causes what's therefore being 5 00:00:18,239 --> 00:00:22,240 Speaker 1: called COVID nineteen. Because everything is a little less scary 6 00:00:22,320 --> 00:00:26,920 Speaker 1: when you understand it better. So first up, let's talk 7 00:00:26,960 --> 00:00:31,280 Speaker 1: about how long viruses can live on surfaces. Because between 8 00:00:31,320 --> 00:00:34,400 Speaker 1: all those door handles, credit card keypads, and even our 9 00:00:34,440 --> 00:00:37,760 Speaker 1: own cell phones, we interact with so many surfaces daily. 10 00:00:38,280 --> 00:00:40,239 Speaker 1: I mean, even if you don't hand your phone over 11 00:00:40,280 --> 00:00:43,080 Speaker 1: to everyone you meet, you probably put it down on, say, 12 00:00:43,159 --> 00:00:45,839 Speaker 1: a table that other people have touched. And that's a 13 00:00:45,920 --> 00:00:49,919 Speaker 1: fact of life. But some of what we colloquially call germs, 14 00:00:50,120 --> 00:00:53,280 Speaker 1: that is viruses, bacteria, and other microbes that can cause 15 00:00:53,320 --> 00:00:57,600 Speaker 1: infections in our bodies, some germs can survive on surfaces 16 00:00:57,600 --> 00:00:59,920 Speaker 1: outside of our bodies long enough to spread from one 17 00:01:00,120 --> 00:01:04,679 Speaker 1: person to another. There's unfortunately no hard and fast rule 18 00:01:04,800 --> 00:01:08,360 Speaker 1: for how long viruses in general can live on surfaces. 19 00:01:08,880 --> 00:01:11,640 Speaker 1: Part of the uncertainty is because viruses are diverse and 20 00:01:11,680 --> 00:01:15,440 Speaker 1: have a variety of surface survival rates. The type of surface, 21 00:01:15,440 --> 00:01:18,680 Speaker 1: and environmental temperature and humidity all come into play too, 22 00:01:19,360 --> 00:01:22,720 Speaker 1: so which surfaces are safe to touch and how often 23 00:01:22,840 --> 00:01:26,360 Speaker 1: do we need to disinfect them? But wait, let's back 24 00:01:26,440 --> 00:01:29,600 Speaker 1: up a step. What are viruses and are they even 25 00:01:29,640 --> 00:01:33,720 Speaker 1: alive in the first place. Things that we generally consider 26 00:01:33,800 --> 00:01:36,960 Speaker 1: to be living have the more or less standalone ability 27 00:01:37,000 --> 00:01:41,800 Speaker 1: to eat, grow, and reproduce. A single celled bacterium or fungi, 28 00:01:41,920 --> 00:01:44,000 Speaker 1: or even a cell from your body can do all 29 00:01:44,040 --> 00:01:47,520 Speaker 1: those things because they contain the genetic instructions to do so, 30 00:01:47,800 --> 00:01:52,639 Speaker 1: plus the enzymes to carry out those instructions. But viruses don't. 31 00:01:53,320 --> 00:01:56,600 Speaker 1: They have the genetic instructions the DNA or RNA, but 32 00:01:56,640 --> 00:01:59,280 Speaker 1: they don't have the right enzymes to create the chemical 33 00:01:59,400 --> 00:02:04,840 Speaker 1: reactions necessary for reproduction. Instead, viruses need a host cell, 34 00:02:05,160 --> 00:02:08,440 Speaker 1: which can be bacteria, fungi, or a planter animal including 35 00:02:08,440 --> 00:02:11,920 Speaker 1: a human. Virus will attack a host cell and release 36 00:02:11,960 --> 00:02:15,680 Speaker 1: its genetic instructions, which hijack the host cells enzymes to 37 00:02:15,880 --> 00:02:19,280 Speaker 1: make new viruses. That's good for the virus but generally 38 00:02:19,320 --> 00:02:22,760 Speaker 1: bad for the host. Without a host cell, a virus 39 00:02:22,840 --> 00:02:26,320 Speaker 1: can't survive long term. However, it does have a short 40 00:02:26,360 --> 00:02:28,960 Speaker 1: window of time during which it can stay functional in 41 00:02:29,080 --> 00:02:31,600 Speaker 1: hopes of infecting a new host and attaching to a 42 00:02:31,680 --> 00:02:35,880 Speaker 1: host cell. Outside of a host, viruses can either stay 43 00:02:35,919 --> 00:02:39,360 Speaker 1: intact and remain infectious, or they can degrade to the 44 00:02:39,360 --> 00:02:42,799 Speaker 1: point that they're merely identifiable, which means that you'll still 45 00:02:42,800 --> 00:02:45,480 Speaker 1: be able to identify them from their genetic material, but 46 00:02:45,560 --> 00:02:49,000 Speaker 1: they won't be capable of seeking out and attacking host cells. 47 00:02:49,760 --> 00:02:51,520 Speaker 1: At the point that a virus on a surface is 48 00:02:51,520 --> 00:02:55,600 Speaker 1: only identifiable, it won't be able to cause harm. The 49 00:02:55,720 --> 00:02:58,680 Speaker 1: length of time that viruses can remain infectious on surfaces 50 00:02:58,800 --> 00:03:04,680 Speaker 1: varies greatly. There are baseline differences between viruses. For example, rhinoviruses, 51 00:03:04,800 --> 00:03:07,640 Speaker 1: the viruses that are mostly responsible for the common cold, 52 00:03:07,840 --> 00:03:11,399 Speaker 1: will last for less than an hour on surfaces. Others, 53 00:03:11,440 --> 00:03:13,960 Speaker 1: such as the norovirus, which is a virus that can 54 00:03:14,000 --> 00:03:17,480 Speaker 1: cause vomiting and diarrhea, can last for weeks, which is 55 00:03:17,480 --> 00:03:21,040 Speaker 1: why noravirus can easily spread both through infected people and 56 00:03:21,120 --> 00:03:27,040 Speaker 1: through contaminated foods and surfaces. There are several types of coronaviruses. 57 00:03:27,480 --> 00:03:31,280 Speaker 1: Most cause mild symptoms and are responsible, along with rhinoviruses, 58 00:03:31,400 --> 00:03:34,120 Speaker 1: for the common cold, but three types are known for 59 00:03:34,160 --> 00:03:39,120 Speaker 1: causing more serious diseases mers, SARS and COVID nineteen, and 60 00:03:39,480 --> 00:03:43,480 Speaker 1: because the coronavirus that causes COVID nineteen is novel, the 61 00:03:43,560 --> 00:03:46,320 Speaker 1: research into how long it can last on surfaces is 62 00:03:46,440 --> 00:03:52,440 Speaker 1: new and ongoing. A study published online on marcht by 63 00:03:52,520 --> 00:03:55,760 Speaker 1: researchers at the National Institutes of Health, the US Centers 64 00:03:55,760 --> 00:03:59,600 Speaker 1: for Disease Control and Prevention, and multiple universities compared the 65 00:03:59,640 --> 00:04:03,680 Speaker 1: novel coronavirus with the coronavirus that causes severe acute respiratory 66 00:04:03,720 --> 00:04:08,120 Speaker 1: syndrome or STARS. This is the most closely related human 67 00:04:08,120 --> 00:04:11,600 Speaker 1: coronavirus to COVID nineteen and was responsible for the two 68 00:04:11,600 --> 00:04:15,520 Speaker 1: thousand three epidemic. This study, which has not been peer 69 00:04:15,520 --> 00:04:18,599 Speaker 1: reviewed as of this recording, found that the two viruses 70 00:04:18,680 --> 00:04:22,040 Speaker 1: have similar viability in the environment, which is to say, 71 00:04:22,240 --> 00:04:26,640 Speaker 1: not a whole whole lot something between rhinovirus and neurovirus. 72 00:04:28,040 --> 00:04:31,159 Speaker 1: The study determined that novel coronavirus could remain infectious for 73 00:04:31,279 --> 00:04:34,880 Speaker 1: up to three days on stainless steel and plastic surfaces, 74 00:04:34,920 --> 00:04:38,240 Speaker 1: but survival on other surfaces was lower, just one day 75 00:04:38,240 --> 00:04:41,200 Speaker 1: on cardboard and four hours on copper, and it was 76 00:04:41,279 --> 00:04:44,120 Speaker 1: lowest of all in the air just up to three hours, 77 00:04:44,839 --> 00:04:47,280 Speaker 1: but keep in mind that these numbers are the maximum 78 00:04:47,320 --> 00:04:50,400 Speaker 1: for the viability of the virus. Viruses start to degrade 79 00:04:50,480 --> 00:04:53,560 Speaker 1: pretty immediately when they're not in a host. The longer 80 00:04:53,600 --> 00:04:56,880 Speaker 1: they're in the air or on a surface, exponentially fewer 81 00:04:56,920 --> 00:05:00,320 Speaker 1: of them will remain infectious. And if your imman system 82 00:05:00,360 --> 00:05:03,320 Speaker 1: is working okay, a lot of individual viruses need to 83 00:05:03,320 --> 00:05:06,120 Speaker 1: get into your body, either via your mucous membranes like 84 00:05:06,200 --> 00:05:08,560 Speaker 1: your eyes, nose, and mouth, or via cuts in your 85 00:05:08,560 --> 00:05:11,640 Speaker 1: skin in order for you to get infected. That's why 86 00:05:11,720 --> 00:05:14,760 Speaker 1: direct person to person contact is still the easiest way 87 00:05:14,800 --> 00:05:17,880 Speaker 1: for coronavirus to spread, and why everyone's telling you to 88 00:05:17,920 --> 00:05:21,240 Speaker 1: wash your hands before touching your face. It's also why 89 00:05:21,279 --> 00:05:24,360 Speaker 1: we don't have more precise numbers for how long coronavirus, 90 00:05:24,440 --> 00:05:26,600 Speaker 1: or any virus for that matter, no matter how long 91 00:05:26,640 --> 00:05:31,280 Speaker 1: they've been studied, can last on surfaces. We spoke via 92 00:05:31,320 --> 00:05:35,440 Speaker 1: email with Dr Alicia Kray, postdoctoral fellow in epidemiology at 93 00:05:35,480 --> 00:05:40,520 Speaker 1: Emory University. She said, generally, survival of pathogens on famites, 94 00:05:40,640 --> 00:05:43,800 Speaker 1: which are objects or materials likely to carry infection, is 95 00:05:43,880 --> 00:05:46,920 Speaker 1: determined by inoculating a surface with a known quantity of 96 00:05:47,000 --> 00:05:50,280 Speaker 1: virus and then sampling at various time intervals to determine 97 00:05:50,320 --> 00:05:54,240 Speaker 1: the amount recovered. Scientists use this information to estimate a 98 00:05:54,279 --> 00:05:57,440 Speaker 1: decay curve for the pathogen on the particular surface, which 99 00:05:57,480 --> 00:06:02,520 Speaker 1: can be extrapolated to longer time in vals. The NIH 100 00:06:02,640 --> 00:06:06,200 Speaker 1: and CDC team that studied surface variation for coronavirus is 101 00:06:06,240 --> 00:06:10,960 Speaker 1: still researching. They're looking into coronavirus viability from snott versus 102 00:06:11,000 --> 00:06:15,159 Speaker 1: flegm versus poop, as well as in varying environmental conditions. 103 00:06:15,880 --> 00:06:19,919 Speaker 1: Because although viruses have differing baseline rates of survival on surfaces, 104 00:06:20,160 --> 00:06:23,360 Speaker 1: additional factors affect their ability to endure outside of a host, 105 00:06:23,520 --> 00:06:28,400 Speaker 1: like temperature, humidity, and properties of the surface itself, Cray said. 106 00:06:28,839 --> 00:06:33,080 Speaker 1: In general, viruses survive longest at lower temperatures, higher humidity, 107 00:06:33,120 --> 00:06:37,000 Speaker 1: and on non porous surfaces like stainless steel. However, some 108 00:06:37,080 --> 00:06:40,960 Speaker 1: viruses do well at low humidity. There have been a 109 00:06:41,000 --> 00:06:44,160 Speaker 1: lot of theories about whether coronavirus will lessen during warmer 110 00:06:44,160 --> 00:06:47,560 Speaker 1: months because dry, cold air like in the winter tends 111 00:06:47,560 --> 00:06:51,480 Speaker 1: to provide favorable conditions for flu transmission, but we simply 112 00:06:51,520 --> 00:06:55,440 Speaker 1: don't know yet. Dr Anthony Fossey, Director of the National 113 00:06:55,480 --> 00:06:59,600 Speaker 1: Institute of Allergy and Infectious Diseases explained during the March thirteen, 114 00:06:59,720 --> 00:07:03,880 Speaker 1: twenty c in Facebook Global Coronavirus town Hall that when 115 00:07:04,000 --> 00:07:08,000 Speaker 1: considering the viability of a virus on various substances, it's 116 00:07:08,040 --> 00:07:11,880 Speaker 1: probably measured in a couple hours. While he recommends wiping 117 00:07:11,880 --> 00:07:14,800 Speaker 1: down surfaces like door knobs and cell phone screens when 118 00:07:14,840 --> 00:07:18,280 Speaker 1: you can, he cautioned against worrying about things like money 119 00:07:18,360 --> 00:07:22,400 Speaker 1: and mail in the end. Despite the differences in viability 120 00:07:22,480 --> 00:07:26,840 Speaker 1: on surfaces among pathogens, fomites, and contexts, the number one 121 00:07:26,840 --> 00:07:30,600 Speaker 1: recommendation for preventing the spread of viruses is standard if 122 00:07:30,640 --> 00:07:33,280 Speaker 1: you've touched a shared surface, wash your hands before you 123 00:07:33,320 --> 00:07:35,240 Speaker 1: touch your face or any part of your body that 124 00:07:35,360 --> 00:07:38,440 Speaker 1: might have a cut or other skin abrasion. The human 125 00:07:38,480 --> 00:07:41,040 Speaker 1: skin is great at keeping out cold and flu viruses 126 00:07:41,440 --> 00:07:44,080 Speaker 1: thanks to its pH and porous nature. They survive for 127 00:07:44,160 --> 00:07:52,120 Speaker 1: only about twenty minutes on our hands. Today's episode was 128 00:07:52,120 --> 00:07:54,960 Speaker 1: written by Carrie Whitney, PhD and produced by Tyler Clang. 129 00:07:55,280 --> 00:07:57,040 Speaker 1: For more on this and lots of other topics, visit 130 00:07:57,080 --> 00:07:59,520 Speaker 1: how stuff works dot com. Brain Stuff is production of 131 00:07:59,560 --> 00:08:01,880 Speaker 1: I heart Rate Dio. For more podcasts. For my heart Radio, 132 00:08:01,960 --> 00:08:04,520 Speaker 1: visit the heart Radio app, Apple podcasts, or wherever you 133 00:08:04,520 --> 00:08:05,720 Speaker 1: listen to your favorite shows.