Why do we have to wear sunscreen? - Kevin P. Boyd
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0:07 - 0:09Most of us think of the Sun as our friend.
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0:09 - 0:11It helps plants grow,
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0:11 - 0:12keeps us warm,
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0:12 - 0:15and who doesn't love to lie on the beach on a sunny day?
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0:15 - 0:17But for all of it's good qualities,
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0:17 - 0:20the Sun can also be harmful in large amounts.
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0:20 - 0:22That's why we invented sunscreen.
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0:22 - 0:25The purpose of sunscreen is to shield the body
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0:25 - 0:27from the Sun's ultraviolet rays,
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0:27 - 0:28which have several harmful effects,
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0:28 - 0:29including sunburn,
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0:29 - 0:30aging,
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0:30 - 0:32and skin cancer promotion.
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0:32 - 0:33These rays are separated
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0:33 - 0:35by their different wave lengths,
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0:35 - 0:37into types such as UVA
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0:37 - 0:38and UVB,
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0:38 - 0:41which exert a variety of effects in the skin
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0:41 - 0:43due to the absorption patterns of chromophores,
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0:43 - 0:44the parts of the molecules
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0:44 - 0:46responsible for their color.
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0:46 - 0:49The primary two chromophores are hemoglobin,
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0:49 - 0:50found in our red blood cells,
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0:50 - 0:53and melanin, which gives our skin its pigment.
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0:53 - 0:56We know that UVB rays cause the skin to burn.
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0:56 - 0:59The role of UVA rays is less well understood
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0:59 - 1:00and appears to have an effect
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1:00 - 1:02on our tanning response,
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1:02 - 1:03carcinogenesis,
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1:03 - 1:04and aging.
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1:04 - 1:07So, how does the sunscreen protect us from these rays?
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1:07 - 1:09There are two basic types of sunscreen,
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1:09 - 1:12physical and chemical blockers.
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1:12 - 1:13Physical blockers, like zinc oxide
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1:13 - 1:15or titanium dioxide,
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1:15 - 1:18reflect the Sun's rays by acting as a physical barrier.
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1:18 - 1:21If you've seen lifeguards with noses covered in white,
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1:21 - 1:22then you know what this looks like.
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1:22 - 1:24The same ingredients are primary components
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1:24 - 1:26of diaper creams,
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1:26 - 1:28where the goal is also to create a physical barrier.
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1:28 - 1:31Historically, they haven't always been easy to apply
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1:31 - 1:33and were conspicuously visible on the skin,
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1:33 - 1:36but new formulations have made this less of an issue.
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1:36 - 1:38Chemical blockers, on the other hand,
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1:38 - 1:40absorb the Sun's rays.
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1:40 - 1:42They deteriorate more quickly than physical sunscreens
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1:42 - 1:46because their ability to absorb the Sun diminishes.
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1:46 - 1:48Generally, these are more transparent
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1:48 - 1:49when rubbed on the skin,
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1:49 - 1:52but some people develop allergric reactions
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1:52 - 1:54to some of the chemicals.
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1:54 - 1:55Regardless of the type of sunscreen,
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1:55 - 1:57all are subjected to testing
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1:57 - 1:59to determine their sunburn protection factor,
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1:59 - 2:01or SPF.
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2:01 - 2:02This is essentially a measure of the protection
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2:02 - 2:05that the sunscreen will provide from UVB rays
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2:05 - 2:07before one begins to burn.
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2:07 - 2:08But even if you don't burn,
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2:08 - 2:10you still need to use sunscreen
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2:10 - 2:12because unless you live in a cave,
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2:12 - 2:14you're not immune to the effects of the Sun.
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2:14 - 2:16It is true that darker skinned people
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2:16 - 2:18and those who tan easily
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2:18 - 2:20have more built-in protection from sunburns,
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2:20 - 2:22but they are still vulnerable
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2:22 - 2:24to the effects of UVA.
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2:24 - 2:26Children under the age of six months,
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2:26 - 2:27on the other hand,
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2:27 - 2:29should have almost no sun exposure
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2:29 - 2:30as their protective mechanisms
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2:30 - 2:31are not fully functioning,
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2:31 - 2:33and their skin is more likely to absorb
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2:33 - 2:35any sunscreen that is applied.
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2:35 - 2:37Wearing sunscreen helps protect
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2:37 - 2:40against the development of all three types of skin cancer:
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2:40 - 2:42basal cell carcinoma,
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2:42 - 2:44squamous cell carcinoma,
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2:44 - 2:46and melanoma.
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2:46 - 2:48On a daily basis, the DNA in your cells
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2:48 - 2:50is developing mutations and errors
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2:50 - 2:52that are generally handled
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2:52 - 2:54by machinery within your cells,
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2:54 - 2:57but ultraviolet rays from the Sun lead to mutations
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2:57 - 2:59that the cell may not be able to overcome,
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2:59 - 3:01leading to uncontrolled growth
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3:01 - 3:03and eventual skin cancer.
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3:03 - 3:04The scariest thing about this
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3:04 - 3:06is that usually you can't even see it happening
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3:06 - 3:08until its too late.
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3:08 - 3:11But if these concrete risks to your health
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3:11 - 3:14are not enough to convince you to use sunscreen,
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3:14 - 3:16there are aesthetic reasons as well.
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3:16 - 3:18Along with cigarette smoking,
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3:18 - 3:21sun damage is the leading cause of premature aging.
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3:21 - 3:23Photoaging from chronic sun exposure
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3:23 - 3:26leads to a loss of elasticity in the skin,
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3:26 - 3:28in other words, making it look saggy.
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3:28 - 3:29Take a look at this truck driver
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3:29 - 3:32who's left side was chronically exposed to the sun
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3:32 - 3:34and notice the difference.
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3:34 - 3:36This is an important point.
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3:36 - 3:39Car windows block UVB, the burn rays,
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3:39 - 3:42but not UVA, the aging rays.
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3:42 - 3:44It is recommended to use sunscreen daily,
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3:44 - 3:46but you should pay special attention
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3:46 - 3:48before prolonged sun exposure
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3:48 - 3:49or when at the beach
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3:49 - 3:50or among snow
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3:50 - 3:52since the reflectivity of water and ice
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3:52 - 3:55amplifies the Sun's rays.
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3:55 - 3:57For these cases, apply about an ounce
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3:57 - 3:59fifteen to thirty minutes before you go out
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3:59 - 4:01and once again soon after you get outside.
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4:01 - 4:04After that, you should reapply it every two to three hours,
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4:04 - 4:07especially after swimming or sweating.
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4:07 - 4:09Otherwise you should wear protective clothing
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4:09 - 4:12with ultraviolet protection factor, or UPF.
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4:12 - 4:13Stay in shaded areas,
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4:13 - 4:15such as under trees or an umbrella,
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4:15 - 4:17and avoid the sun at the peak hours
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4:17 - 4:19of 10 a.m. to 4 p.m.
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4:19 - 4:21And what's the best kind of sunscreen?
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4:21 - 4:23Everyone will have their preference,
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4:23 - 4:25but look for the following things:
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4:25 - 4:26broad spectra,
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4:26 - 4:28SPF of at least 30,
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4:28 - 4:29and water-resistant.
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4:29 - 4:31A light moisturizer with SPF 30
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4:31 - 4:34should be good for daily use.
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4:34 - 4:35Take note if you decide to use a spray.
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4:35 - 4:38They take several coats to effectively cover your skin,
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4:38 - 4:40like painting a wall with a spray can
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4:40 - 4:42versus a paint brush.
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4:42 - 4:44So, enjoy the sun,
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4:44 - 4:46but enjoy it with sunscreen.
- Title:
- Why do we have to wear sunscreen? - Kevin P. Boyd
- Description:
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View full lesson: http://ed.ted.com/lessons/why-do-we-have-to-wear-sunscreen-kevin-p-boyd
You already know that a trip to the beach can give you a nasty sunburn, but the nitty gritty of sun safety is actually much more complex. Wrinkle-causing UVA rays and burn-inducing UVB's can pose a serious risk to your health (and good looks). So what can you do? Kevin P. Boyd makes the case to slap on some physical or chemical SPF daily.
Lesson by Kevin P. Boyd, animation by Andrew Foerster.
- Video Language:
- English
- Team:
closed TED
- Project:
- TED-Ed
- Duration:
- 05:02
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Jessica Ruby approved English subtitles for Why do we have to wear sunscreen? - Kevin P. Boyd | |
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Jessica Ruby edited English subtitles for Why do we have to wear sunscreen? - Kevin P. Boyd | |
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Jessica Ruby edited English subtitles for Why do we have to wear sunscreen? - Kevin P. Boyd | |
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TED edited English subtitles for Why do we have to wear sunscreen? - Kevin P. Boyd | |
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TED edited English subtitles for Why do we have to wear sunscreen? - Kevin P. Boyd | |
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TED edited English subtitles for Why do we have to wear sunscreen? - Kevin P. Boyd | |
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Jessica Ruby approved English subtitles for Why do we have to wear sunscreen? - Kevin P. Boyd | |
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Jessica Ruby accepted English subtitles for Why do we have to wear sunscreen? - Kevin P. Boyd |