[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,0:00:06.79,0:00:09.41,Default,,0000,0000,0000,,Most of us think of the Sun as our friend.
Dialogue: 0,0:00:09.41,0:00:10.85,Default,,0000,0000,0000,,It helps plants grow,
Dialogue: 0,0:00:10.85,0:00:11.86,Default,,0000,0000,0000,,keeps us warm,
Dialogue: 0,0:00:11.86,0:00:15.04,Default,,0000,0000,0000,,and who doesn't love to lie on the beach on a sunny day?
Dialogue: 0,0:00:15.04,0:00:16.69,Default,,0000,0000,0000,,But for all of it's good qualities,
Dialogue: 0,0:00:16.69,0:00:19.66,Default,,0000,0000,0000,,the Sun can also be harmful in large amounts.
Dialogue: 0,0:00:19.66,0:00:22.42,Default,,0000,0000,0000,,That's why we invented sunscreen.
Dialogue: 0,0:00:22.42,0:00:24.50,Default,,0000,0000,0000,,The purpose of sunscreen is to shield the body
Dialogue: 0,0:00:24.50,0:00:26.68,Default,,0000,0000,0000,,from the Sun's ultraviolet rays,
Dialogue: 0,0:00:26.68,0:00:28.22,Default,,0000,0000,0000,,which have several harmful effects,
Dialogue: 0,0:00:28.22,0:00:29.19,Default,,0000,0000,0000,,including sunburn,
Dialogue: 0,0:00:29.19,0:00:29.84,Default,,0000,0000,0000,,aging,
Dialogue: 0,0:00:29.84,0:00:32.14,Default,,0000,0000,0000,,and skin cancer promotion.
Dialogue: 0,0:00:32.14,0:00:33.47,Default,,0000,0000,0000,,These rays are separated
Dialogue: 0,0:00:33.47,0:00:35.11,Default,,0000,0000,0000,,by their different wave lengths,
Dialogue: 0,0:00:35.11,0:00:36.72,Default,,0000,0000,0000,,into types such as UVA
Dialogue: 0,0:00:36.72,0:00:38.31,Default,,0000,0000,0000,,and UVB,
Dialogue: 0,0:00:38.31,0:00:40.52,Default,,0000,0000,0000,,which exert a variety of effects in the skin
Dialogue: 0,0:00:40.52,0:00:43.30,Default,,0000,0000,0000,,due to the absorption patterns of chromophores,
Dialogue: 0,0:00:43.30,0:00:44.32,Default,,0000,0000,0000,,the parts of the molecules
Dialogue: 0,0:00:44.32,0:00:46.06,Default,,0000,0000,0000,,responsible for their color.
Dialogue: 0,0:00:46.06,0:00:48.57,Default,,0000,0000,0000,,The primary two chromophores are hemoglobin,
Dialogue: 0,0:00:48.57,0:00:50.21,Default,,0000,0000,0000,,found in our red blood cells,
Dialogue: 0,0:00:50.21,0:00:53.21,Default,,0000,0000,0000,,and melanin, which gives our skin its pigment.
Dialogue: 0,0:00:53.21,0:00:56.19,Default,,0000,0000,0000,,We know that UVB rays cause the skin to burn.
Dialogue: 0,0:00:56.19,0:00:58.87,Default,,0000,0000,0000,,The role of UVA rays is less well understood
Dialogue: 0,0:00:58.87,0:01:00.41,Default,,0000,0000,0000,,and appears to have an effect
Dialogue: 0,0:01:00.41,0:01:02.04,Default,,0000,0000,0000,,on our tanning response,
Dialogue: 0,0:01:02.04,0:01:03.13,Default,,0000,0000,0000,,carcinogenesis,
Dialogue: 0,0:01:03.13,0:01:04.46,Default,,0000,0000,0000,,and aging.
Dialogue: 0,0:01:04.46,0:01:07.12,Default,,0000,0000,0000,,So, how does the sunscreen protect us from these rays?
Dialogue: 0,0:01:07.12,0:01:09.09,Default,,0000,0000,0000,,There are two basic types of sunscreen,
Dialogue: 0,0:01:09.09,0:01:11.79,Default,,0000,0000,0000,,physical and chemical blockers.
Dialogue: 0,0:01:11.79,0:01:13.34,Default,,0000,0000,0000,,Physical blockers, like zinc oxide
Dialogue: 0,0:01:13.34,0:01:15.41,Default,,0000,0000,0000,,or titanium dioxide,
Dialogue: 0,0:01:15.41,0:01:18.40,Default,,0000,0000,0000,,reflect the Sun's rays by acting as a physical barrier.
Dialogue: 0,0:01:18.40,0:01:20.60,Default,,0000,0000,0000,,If you've seen lifeguards with noses covered in white,
Dialogue: 0,0:01:20.60,0:01:22.23,Default,,0000,0000,0000,,then you know what this looks like.
Dialogue: 0,0:01:22.23,0:01:24.36,Default,,0000,0000,0000,,The same ingredients are primary components
Dialogue: 0,0:01:24.36,0:01:25.54,Default,,0000,0000,0000,,of diaper creams,
Dialogue: 0,0:01:25.54,0:01:28.23,Default,,0000,0000,0000,,where the goal is also to create a physical barrier.
Dialogue: 0,0:01:28.23,0:01:30.53,Default,,0000,0000,0000,,Historically, they haven't always been easy to apply
Dialogue: 0,0:01:30.53,0:01:33.16,Default,,0000,0000,0000,,and were conspicuously visible on the skin,
Dialogue: 0,0:01:33.16,0:01:36.16,Default,,0000,0000,0000,,but new formulations have made this less of an issue.
Dialogue: 0,0:01:36.16,0:01:37.93,Default,,0000,0000,0000,,Chemical blockers, on the other hand,
Dialogue: 0,0:01:37.93,0:01:39.81,Default,,0000,0000,0000,,absorb the Sun's rays.
Dialogue: 0,0:01:39.81,0:01:42.37,Default,,0000,0000,0000,,They deteriorate more quickly than physical sunscreens
Dialogue: 0,0:01:42.37,0:01:46.10,Default,,0000,0000,0000,,because their ability to absorb the Sun diminishes.
Dialogue: 0,0:01:46.10,0:01:48.02,Default,,0000,0000,0000,,Generally, these are more transparent
Dialogue: 0,0:01:48.02,0:01:49.49,Default,,0000,0000,0000,,when rubbed on the skin,
Dialogue: 0,0:01:49.49,0:01:51.63,Default,,0000,0000,0000,,but some people develop allergric reactions
Dialogue: 0,0:01:51.63,0:01:53.52,Default,,0000,0000,0000,,to some of the chemicals.
Dialogue: 0,0:01:53.52,0:01:55.34,Default,,0000,0000,0000,,Regardless of the type of sunscreen,
Dialogue: 0,0:01:55.34,0:01:56.91,Default,,0000,0000,0000,,all are subjected to testing
Dialogue: 0,0:01:56.91,0:01:59.26,Default,,0000,0000,0000,,to determine their sunburn protection factor,
Dialogue: 0,0:01:59.26,0:02:00.66,Default,,0000,0000,0000,,or SPF.
Dialogue: 0,0:02:00.66,0:02:02.43,Default,,0000,0000,0000,,This is essentially a measure of the protection
Dialogue: 0,0:02:02.43,0:02:05.30,Default,,0000,0000,0000,,that the sunscreen will provide from UVB rays
Dialogue: 0,0:02:05.30,0:02:07.01,Default,,0000,0000,0000,,before one begins to burn.
Dialogue: 0,0:02:07.01,0:02:08.30,Default,,0000,0000,0000,,But even if you don't burn,
Dialogue: 0,0:02:08.30,0:02:09.90,Default,,0000,0000,0000,,you still need to use sunscreen
Dialogue: 0,0:02:09.90,0:02:11.68,Default,,0000,0000,0000,,because unless you live in a cave,
Dialogue: 0,0:02:11.68,0:02:14.50,Default,,0000,0000,0000,,you're not immune to the effects of the Sun.
Dialogue: 0,0:02:14.50,0:02:16.49,Default,,0000,0000,0000,,It is true that darker skinned people
Dialogue: 0,0:02:16.49,0:02:17.60,Default,,0000,0000,0000,,and those who tan easily
Dialogue: 0,0:02:17.60,0:02:20.32,Default,,0000,0000,0000,,have more built-in protection from sunburns,
Dialogue: 0,0:02:20.32,0:02:21.99,Default,,0000,0000,0000,,but they are still vulnerable
Dialogue: 0,0:02:21.99,0:02:23.82,Default,,0000,0000,0000,,to the effects of UVA.
Dialogue: 0,0:02:23.82,0:02:25.81,Default,,0000,0000,0000,,Children under the age of six months,
Dialogue: 0,0:02:25.81,0:02:26.66,Default,,0000,0000,0000,,on the other hand,
Dialogue: 0,0:02:26.66,0:02:28.53,Default,,0000,0000,0000,,should have almost no sun exposure
Dialogue: 0,0:02:28.53,0:02:29.95,Default,,0000,0000,0000,,as their protective mechanisms
Dialogue: 0,0:02:29.95,0:02:31.49,Default,,0000,0000,0000,,are not fully functioning,
Dialogue: 0,0:02:31.49,0:02:33.08,Default,,0000,0000,0000,,and their skin is more likely to absorb
Dialogue: 0,0:02:33.08,0:02:35.45,Default,,0000,0000,0000,,any sunscreen that is applied.
Dialogue: 0,0:02:35.45,0:02:37.01,Default,,0000,0000,0000,,Wearing sunscreen helps protect
Dialogue: 0,0:02:37.01,0:02:40.30,Default,,0000,0000,0000,,against the development of all three types of skin cancer:
Dialogue: 0,0:02:40.30,0:02:42.34,Default,,0000,0000,0000,,basal cell carcinoma,
Dialogue: 0,0:02:42.34,0:02:44.22,Default,,0000,0000,0000,,squamous cell carcinoma,
Dialogue: 0,0:02:44.22,0:02:45.84,Default,,0000,0000,0000,,and melanoma.
Dialogue: 0,0:02:45.84,0:02:47.97,Default,,0000,0000,0000,,On a daily basis, the DNA in your cells
Dialogue: 0,0:02:47.97,0:02:49.92,Default,,0000,0000,0000,,is developing mutations and errors
Dialogue: 0,0:02:49.92,0:02:51.60,Default,,0000,0000,0000,,that are generally handled
Dialogue: 0,0:02:51.60,0:02:53.68,Default,,0000,0000,0000,,by machinery within your cells,
Dialogue: 0,0:02:53.68,0:02:57.16,Default,,0000,0000,0000,,but ultraviolet rays from the Sun lead to mutations
Dialogue: 0,0:02:57.16,0:02:59.22,Default,,0000,0000,0000,,that the cell may not be able to overcome,
Dialogue: 0,0:02:59.22,0:03:00.86,Default,,0000,0000,0000,,leading to uncontrolled growth
Dialogue: 0,0:03:00.86,0:03:02.69,Default,,0000,0000,0000,,and eventual skin cancer.
Dialogue: 0,0:03:02.69,0:03:04.19,Default,,0000,0000,0000,,The scariest thing about this
Dialogue: 0,0:03:04.19,0:03:06.46,Default,,0000,0000,0000,,is that usually you can't even see it happening
Dialogue: 0,0:03:06.46,0:03:08.16,Default,,0000,0000,0000,,until its too late.
Dialogue: 0,0:03:08.16,0:03:10.58,Default,,0000,0000,0000,,But if these concrete risks to your health
Dialogue: 0,0:03:10.58,0:03:13.61,Default,,0000,0000,0000,,are not enough to convince you to use sunscreen,
Dialogue: 0,0:03:13.61,0:03:16.12,Default,,0000,0000,0000,,there are aesthetic reasons as well.
Dialogue: 0,0:03:16.12,0:03:17.60,Default,,0000,0000,0000,,Along with cigarette smoking,
Dialogue: 0,0:03:17.60,0:03:20.75,Default,,0000,0000,0000,,sun damage is the leading cause of premature aging.
Dialogue: 0,0:03:20.75,0:03:22.75,Default,,0000,0000,0000,,Photoaging from chronic sun exposure
Dialogue: 0,0:03:22.75,0:03:25.51,Default,,0000,0000,0000,,leads to a loss of elasticity in the skin,
Dialogue: 0,0:03:25.51,0:03:28.33,Default,,0000,0000,0000,,in other words, making it look saggy.
Dialogue: 0,0:03:28.33,0:03:29.43,Default,,0000,0000,0000,,Take a look at this truck driver
Dialogue: 0,0:03:29.43,0:03:32.17,Default,,0000,0000,0000,,who's left side was chronically exposed to the sun
Dialogue: 0,0:03:32.17,0:03:33.91,Default,,0000,0000,0000,,and notice the difference.
Dialogue: 0,0:03:33.91,0:03:35.85,Default,,0000,0000,0000,,This is an important point.
Dialogue: 0,0:03:35.85,0:03:38.74,Default,,0000,0000,0000,,Car windows block UVB, the burn rays,
Dialogue: 0,0:03:38.74,0:03:41.69,Default,,0000,0000,0000,,but not UVA, the aging rays.
Dialogue: 0,0:03:41.69,0:03:44.28,Default,,0000,0000,0000,,It is recommended to use sunscreen daily,
Dialogue: 0,0:03:44.28,0:03:45.75,Default,,0000,0000,0000,,but you should pay special attention
Dialogue: 0,0:03:45.75,0:03:47.69,Default,,0000,0000,0000,,before prolonged sun exposure
Dialogue: 0,0:03:47.69,0:03:48.90,Default,,0000,0000,0000,,or when at the beach
Dialogue: 0,0:03:48.90,0:03:50.12,Default,,0000,0000,0000,,or among snow
Dialogue: 0,0:03:50.12,0:03:52.42,Default,,0000,0000,0000,,since the reflectivity of water and ice
Dialogue: 0,0:03:52.42,0:03:54.76,Default,,0000,0000,0000,,amplifies the Sun's rays.
Dialogue: 0,0:03:54.76,0:03:56.83,Default,,0000,0000,0000,,For these cases, apply about an ounce
Dialogue: 0,0:03:56.83,0:03:58.96,Default,,0000,0000,0000,,fifteen to thirty minutes before you go out
Dialogue: 0,0:03:58.96,0:04:01.16,Default,,0000,0000,0000,,and once again soon after you get outside.
Dialogue: 0,0:04:01.16,0:04:04.32,Default,,0000,0000,0000,,After that, you should reapply it every two to three hours,
Dialogue: 0,0:04:04.32,0:04:06.91,Default,,0000,0000,0000,,especially after swimming or sweating.
Dialogue: 0,0:04:06.91,0:04:08.51,Default,,0000,0000,0000,,Otherwise you should wear protective clothing
Dialogue: 0,0:04:08.51,0:04:12.17,Default,,0000,0000,0000,,with ultraviolet protection factor, or UPF.
Dialogue: 0,0:04:12.17,0:04:13.25,Default,,0000,0000,0000,,Stay in shaded areas,
Dialogue: 0,0:04:13.25,0:04:15.05,Default,,0000,0000,0000,,such as under trees or an umbrella,
Dialogue: 0,0:04:15.05,0:04:16.64,Default,,0000,0000,0000,,and avoid the sun at the peak hours
Dialogue: 0,0:04:16.64,0:04:18.60,Default,,0000,0000,0000,,of 10 a.m. to 4 p.m.
Dialogue: 0,0:04:18.60,0:04:20.98,Default,,0000,0000,0000,,And what's the best kind of sunscreen?
Dialogue: 0,0:04:20.98,0:04:22.54,Default,,0000,0000,0000,,Everyone will have their preference,
Dialogue: 0,0:04:22.54,0:04:24.67,Default,,0000,0000,0000,,but look for the following things:
Dialogue: 0,0:04:24.67,0:04:25.75,Default,,0000,0000,0000,,broad spectra,
Dialogue: 0,0:04:25.75,0:04:27.86,Default,,0000,0000,0000,,SPF of at least 30,
Dialogue: 0,0:04:27.86,0:04:29.36,Default,,0000,0000,0000,,and water-resistant.
Dialogue: 0,0:04:29.36,0:04:31.36,Default,,0000,0000,0000,,A light moisturizer with SPF 30
Dialogue: 0,0:04:31.36,0:04:33.52,Default,,0000,0000,0000,,should be good for daily use.
Dialogue: 0,0:04:33.52,0:04:35.50,Default,,0000,0000,0000,,Take note if you decide to use a spray.
Dialogue: 0,0:04:35.50,0:04:38.42,Default,,0000,0000,0000,,They take several coats to effectively cover your skin,
Dialogue: 0,0:04:38.42,0:04:40.33,Default,,0000,0000,0000,,like painting a wall with a spray can
Dialogue: 0,0:04:40.33,0:04:41.97,Default,,0000,0000,0000,,versus a paint brush.
Dialogue: 0,0:04:41.97,0:04:43.83,Default,,0000,0000,0000,,So, enjoy the sun,
Dialogue: 0,0:04:43.83,0:04:46.22,Default,,0000,0000,0000,,but enjoy it with sunscreen.