[Script Info] Title: [Events] Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text Dialogue: 0,0:00:06.00,0:00:09.00,Default,,0000,0000,0000,,Most of us think of the Sun as our friend. Dialogue: 0,0:00:09.00,0:00:10.00,Default,,0000,0000,0000,,It helps plants grow, Dialogue: 0,0:00:10.00,0:00:11.00,Default,,0000,0000,0000,,keeps us warm, Dialogue: 0,0:00:11.00,0:00:15.00,Default,,0000,0000,0000,,and who doesn't love to lie on the beach on a sunny day? Dialogue: 0,0:00:15.00,0:00:16.00,Default,,0000,0000,0000,,But for all of it's good qualities, Dialogue: 0,0:00:16.00,0:00:19.00,Default,,0000,0000,0000,,the Sun can also be harmful in large amounts. Dialogue: 0,0:00:19.00,0:00:22.00,Default,,0000,0000,0000,,That's why we invented sunscreen. Dialogue: 0,0:00:22.00,0:00:24.00,Default,,0000,0000,0000,,The purpose of sunscreen is to shield the body Dialogue: 0,0:00:24.00,0:00:26.00,Default,,0000,0000,0000,,from the Sun's ultraviolet rays, Dialogue: 0,0:00:26.00,0:00:28.00,Default,,0000,0000,0000,,which have several harmful effects, Dialogue: 0,0:00:28.00,0:00:29.00,Default,,0000,0000,0000,,including sunburn, Dialogue: 0,0:00:29.00,0:00:29.00,Default,,0000,0000,0000,,aging, Dialogue: 0,0:00:29.00,0:00:32.00,Default,,0000,0000,0000,,and skin cancer promotion. Dialogue: 0,0:00:32.00,0:00:33.00,Default,,0000,0000,0000,,These rays are separated Dialogue: 0,0:00:33.00,0:00:35.00,Default,,0000,0000,0000,,by their different wave lengths, Dialogue: 0,0:00:35.00,0:00:36.00,Default,,0000,0000,0000,,into types such as UVA Dialogue: 0,0:00:36.00,0:00:38.00,Default,,0000,0000,0000,,and UVB, Dialogue: 0,0:00:38.00,0:00:40.00,Default,,0000,0000,0000,,which exert a variety of effects in the skin Dialogue: 0,0:00:40.00,0:00:43.00,Default,,0000,0000,0000,,due to the absorption patterns of chromophores, Dialogue: 0,0:00:43.00,0:00:44.00,Default,,0000,0000,0000,,the parts of the molecules Dialogue: 0,0:00:44.00,0:00:46.00,Default,,0000,0000,0000,,responsible for their color. Dialogue: 0,0:00:46.00,0:00:48.00,Default,,0000,0000,0000,,The primary two chromophores are hemoglobin, Dialogue: 0,0:00:48.00,0:00:50.00,Default,,0000,0000,0000,,found in our red blood cells, Dialogue: 0,0:00:50.00,0:00:53.00,Default,,0000,0000,0000,,and melanin, which gives our skin its pigment. Dialogue: 0,0:00:53.00,0:00:56.00,Default,,0000,0000,0000,,We know that UVB rays cause the skin to burn. Dialogue: 0,0:00:56.00,0:00:58.00,Default,,0000,0000,0000,,The role of UVA rays is less well understood Dialogue: 0,0:00:58.00,0:01:00.00,Default,,0000,0000,0000,,and appears to have an effect Dialogue: 0,0:01:00.00,0:01:02.00,Default,,0000,0000,0000,,on our tanning response, Dialogue: 0,0:01:02.00,0:01:03.00,Default,,0000,0000,0000,,carcinogenesis, Dialogue: 0,0:01:03.00,0:01:04.00,Default,,0000,0000,0000,,and aging. Dialogue: 0,0:01:04.00,0:01:07.00,Default,,0000,0000,0000,,So, how does the sunscreen protect us from these rays? Dialogue: 0,0:01:07.00,0:01:09.00,Default,,0000,0000,0000,,There are two basic types of sunscreen, Dialogue: 0,0:01:09.00,0:01:11.00,Default,,0000,0000,0000,,physical and chemical blockers. Dialogue: 0,0:01:11.00,0:01:13.00,Default,,0000,0000,0000,,Physical blockers, like zinc oxide Dialogue: 0,0:01:13.00,0:01:15.00,Default,,0000,0000,0000,,or titanium dioxide, Dialogue: 0,0:01:15.00,0:01:18.00,Default,,0000,0000,0000,,reflect the Sun's rays by acting as a physical barrier. Dialogue: 0,0:01:18.00,0:01:20.00,Default,,0000,0000,0000,,If you've seen lifeguards with noses covered in white, Dialogue: 0,0:01:20.00,0:01:22.00,Default,,0000,0000,0000,,then you know what this looks like. Dialogue: 0,0:01:22.00,0:01:24.00,Default,,0000,0000,0000,,The same ingredients are primary components Dialogue: 0,0:01:24.00,0:01:25.00,Default,,0000,0000,0000,,of diaper creams, Dialogue: 0,0:01:25.00,0:01:28.00,Default,,0000,0000,0000,,where the goal is also to create a physical barrier. Dialogue: 0,0:01:28.00,0:01:30.00,Default,,0000,0000,0000,,Historically, they haven't always been easy to apply Dialogue: 0,0:01:30.00,0:01:33.00,Default,,0000,0000,0000,,and were conspicuously visible on the skin, Dialogue: 0,0:01:33.00,0:01:36.00,Default,,0000,0000,0000,,but new formulations have made this less of an issue. Dialogue: 0,0:01:36.00,0:01:37.00,Default,,0000,0000,0000,,Chemical blockers, on the other hand, Dialogue: 0,0:01:37.00,0:01:39.00,Default,,0000,0000,0000,,absorb the Sun's rays. Dialogue: 0,0:01:39.00,0:01:42.00,Default,,0000,0000,0000,,They deteriorate more quickly than physical sunscreens Dialogue: 0,0:01:42.00,0:01:46.00,Default,,0000,0000,0000,,because their ability to absorb the Sun diminishes. Dialogue: 0,0:01:46.00,0:01:48.00,Default,,0000,0000,0000,,Generally, these are more transparent Dialogue: 0,0:01:48.00,0:01:49.00,Default,,0000,0000,0000,,when rubbed on the skin, Dialogue: 0,0:01:49.00,0:01:51.00,Default,,0000,0000,0000,,but some people develop allergric reactions Dialogue: 0,0:01:51.00,0:01:53.00,Default,,0000,0000,0000,,to some of the chemicals. Dialogue: 0,0:01:53.00,0:01:55.00,Default,,0000,0000,0000,,Regardless to the type of sunscreen, Dialogue: 0,0:01:55.00,0:01:56.00,Default,,0000,0000,0000,,all are subjected to testing Dialogue: 0,0:01:56.00,0:01:59.00,Default,,0000,0000,0000,,to determine their sunburn protection factor, Dialogue: 0,0:01:59.00,0:02:00.00,Default,,0000,0000,0000,,or SPF. Dialogue: 0,0:02:00.00,0:02:02.00,Default,,0000,0000,0000,,This is essentially a measure of the protection Dialogue: 0,0:02:02.00,0:02:05.00,Default,,0000,0000,0000,,that the sunscreen will provide from UVB rays Dialogue: 0,0:02:05.00,0:02:07.00,Default,,0000,0000,0000,,before one begins to burn. Dialogue: 0,0:02:07.00,0:02:08.00,Default,,0000,0000,0000,,But even if you don't burn, Dialogue: 0,0:02:08.00,0:02:09.00,Default,,0000,0000,0000,,you still need to use sunscreen Dialogue: 0,0:02:09.00,0:02:11.00,Default,,0000,0000,0000,,because unless you live in a cave, Dialogue: 0,0:02:11.00,0:02:14.00,Default,,0000,0000,0000,,you're not immune to the effects of the Sun. Dialogue: 0,0:02:14.00,0:02:16.00,Default,,0000,0000,0000,,It is true that darker-skinned people Dialogue: 0,0:02:16.00,0:02:17.00,Default,,0000,0000,0000,,and those who tan easily Dialogue: 0,0:02:17.00,0:02:20.00,Default,,0000,0000,0000,,have more built-in protection from sunburns, Dialogue: 0,0:02:20.00,0:02:21.00,Default,,0000,0000,0000,,but they are still vulnerable Dialogue: 0,0:02:21.00,0:02:23.00,Default,,0000,0000,0000,,to the effects of UVA. Dialogue: 0,0:02:23.00,0:02:25.00,Default,,0000,0000,0000,,Children under the age of six months, Dialogue: 0,0:02:25.00,0:02:26.00,Default,,0000,0000,0000,,on the other hand, Dialogue: 0,0:02:26.00,0:02:28.00,Default,,0000,0000,0000,,should have almost no sun exposure Dialogue: 0,0:02:28.00,0:02:29.00,Default,,0000,0000,0000,,as their protective mechanisms Dialogue: 0,0:02:29.00,0:02:31.00,Default,,0000,0000,0000,,are not fully functioning Dialogue: 0,0:02:31.00,0:02:33.00,Default,,0000,0000,0000,,and their skin is more likely to absorb Dialogue: 0,0:02:33.00,0:02:35.00,Default,,0000,0000,0000,,any sunscreen that is applied. Dialogue: 0,0:02:35.00,0:02:37.00,Default,,0000,0000,0000,,Wearing sunscreen helps protect Dialogue: 0,0:02:37.00,0:02:40.00,Default,,0000,0000,0000,,against the development of all three types of skin cancer: Dialogue: 0,0:02:40.00,0:02:42.00,Default,,0000,0000,0000,,basal cell carcinoma, Dialogue: 0,0:02:42.00,0:02:44.00,Default,,0000,0000,0000,,squamous cell carcinoma, Dialogue: 0,0:02:44.00,0:02:45.00,Default,,0000,0000,0000,,and melanoma. Dialogue: 0,0:02:45.00,0:02:47.00,Default,,0000,0000,0000,,On a daily basis, the DNA in your cells Dialogue: 0,0:02:47.00,0:02:49.00,Default,,0000,0000,0000,,is developing mutations and errors Dialogue: 0,0:02:49.00,0:02:51.00,Default,,0000,0000,0000,,that are generally handled Dialogue: 0,0:02:51.00,0:02:53.00,Default,,0000,0000,0000,,by machinery within your cells, Dialogue: 0,0:02:53.00,0:02:57.00,Default,,0000,0000,0000,,but ultraviolet rays from the Sun lead to mutations Dialogue: 0,0:02:57.00,0:02:59.00,Default,,0000,0000,0000,,that the cell may not be able to overcome, Dialogue: 0,0:02:59.00,0:03:00.00,Default,,0000,0000,0000,,leading to uncontrolled growth Dialogue: 0,0:03:00.00,0:03:02.00,Default,,0000,0000,0000,,and eventual skin cancer. Dialogue: 0,0:03:02.00,0:03:04.00,Default,,0000,0000,0000,,The scariest thing about this Dialogue: 0,0:03:04.00,0:03:06.00,Default,,0000,0000,0000,,is that usually you can't even see it happening Dialogue: 0,0:03:06.00,0:03:08.00,Default,,0000,0000,0000,,until its too late. Dialogue: 0,0:03:08.00,0:03:10.00,Default,,0000,0000,0000,,But if these concrete risks to your health Dialogue: 0,0:03:10.00,0:03:13.00,Default,,0000,0000,0000,,are not enough to convince you to use sunscreen, Dialogue: 0,0:03:13.00,0:03:16.00,Default,,0000,0000,0000,,there are aesthetic reasons as well. Dialogue: 0,0:03:16.00,0:03:17.00,Default,,0000,0000,0000,,Along with cigarette smoking, Dialogue: 0,0:03:17.00,0:03:20.00,Default,,0000,0000,0000,,sun damage is the leading cause of premature aging. Dialogue: 0,0:03:20.00,0:03:22.00,Default,,0000,0000,0000,,Photoaging from chronic sun exposure Dialogue: 0,0:03:22.00,0:03:25.00,Default,,0000,0000,0000,,leads to a loss of elasticity in the skin, Dialogue: 0,0:03:25.00,0:03:28.00,Default,,0000,0000,0000,,in other words, making it look saggy. Dialogue: 0,0:03:28.00,0:03:29.00,Default,,0000,0000,0000,,Take a look at this truck driver Dialogue: 0,0:03:29.00,0:03:32.00,Default,,0000,0000,0000,,who's left side was chronically exposed to the sun Dialogue: 0,0:03:32.00,0:03:33.00,Default,,0000,0000,0000,,and notice the difference. Dialogue: 0,0:03:33.00,0:03:35.00,Default,,0000,0000,0000,,This is an important point. Dialogue: 0,0:03:35.00,0:03:38.00,Default,,0000,0000,0000,,Car windows block UVB, the burn rays, Dialogue: 0,0:03:38.00,0:03:41.00,Default,,0000,0000,0000,,but not UVA, the aging rays. Dialogue: 0,0:03:41.00,0:03:44.00,Default,,0000,0000,0000,,It is recommended to use sunscreen daily, Dialogue: 0,0:03:44.00,0:03:45.00,Default,,0000,0000,0000,,but you should pay special attention Dialogue: 0,0:03:45.00,0:03:47.00,Default,,0000,0000,0000,,before prolonged sun exposure Dialogue: 0,0:03:47.00,0:03:48.00,Default,,0000,0000,0000,,or when at the beach Dialogue: 0,0:03:48.00,0:03:50.00,Default,,0000,0000,0000,,or among snow Dialogue: 0,0:03:50.00,0:03:52.00,Default,,0000,0000,0000,,since the reflectivity of water and ice Dialogue: 0,0:03:52.00,0:03:54.00,Default,,0000,0000,0000,,amplifies the Sun's rays. Dialogue: 0,0:03:54.00,0:03:56.00,Default,,0000,0000,0000,,For these cases, apply about an ounce Dialogue: 0,0:03:56.00,0:03:58.00,Default,,0000,0000,0000,,fifteen to thirty minutes before you go out Dialogue: 0,0:03:58.00,0:04:01.00,Default,,0000,0000,0000,,and once again soon after you get outside. Dialogue: 0,0:04:01.00,0:04:04.00,Default,,0000,0000,0000,,After that, you should reapply it every two to three hours, Dialogue: 0,0:04:04.00,0:04:06.00,Default,,0000,0000,0000,,especially after swimming or sweating. Dialogue: 0,0:04:06.00,0:04:08.00,Default,,0000,0000,0000,,Otherwise you should wear protective clothing Dialogue: 0,0:04:08.00,0:04:12.00,Default,,0000,0000,0000,,with ultraviolet protection factor, or UPF. Dialogue: 0,0:04:12.00,0:04:13.00,Default,,0000,0000,0000,,Stay in shaded areas, Dialogue: 0,0:04:13.00,0:04:15.00,Default,,0000,0000,0000,,such as under trees or an umbrella, Dialogue: 0,0:04:15.00,0:04:16.00,Default,,0000,0000,0000,,and avoid the sun at the peak hours Dialogue: 0,0:04:16.00,0:04:18.00,Default,,0000,0000,0000,,of 10 a.m. to 4 p.m. Dialogue: 0,0:04:18.00,0:04:20.00,Default,,0000,0000,0000,,And what's the best kind of sunscreen? Dialogue: 0,0:04:20.00,0:04:22.00,Default,,0000,0000,0000,,Everyone will have their preference, Dialogue: 0,0:04:22.00,0:04:24.00,Default,,0000,0000,0000,,but look for the following things: Dialogue: 0,0:04:24.00,0:04:25.00,Default,,0000,0000,0000,,broad spectra, Dialogue: 0,0:04:25.00,0:04:27.00,Default,,0000,0000,0000,,SPF of at least 30, Dialogue: 0,0:04:27.00,0:04:29.00,Default,,0000,0000,0000,,and water-resistant. Dialogue: 0,0:04:29.00,0:04:31.00,Default,,0000,0000,0000,,A light moisturizer with SPF 30 Dialogue: 0,0:04:31.00,0:04:33.00,Default,,0000,0000,0000,,should be good for daily use. Dialogue: 0,0:04:33.00,0:04:35.00,Default,,0000,0000,0000,,Take note if you decide to use a spray. Dialogue: 0,0:04:35.00,0:04:38.00,Default,,0000,0000,0000,,They take several coats to effectively cover your skin, Dialogue: 0,0:04:38.00,0:04:40.00,Default,,0000,0000,0000,,like painting a wall with a spray can Dialogue: 0,0:04:40.00,0:04:41.00,Default,,0000,0000,0000,,versus a paint brush. Dialogue: 0,0:04:41.00,0:04:43.00,Default,,0000,0000,0000,,So, enjoy the sun, Dialogue: 0,0:04:43.00,0:04:46.00,Default,,0000,0000,0000,,but enjoy it with sunscreen.