Why do we have to wear sunscreen Kevin P. Boyd

Most of us think of the Sun as our friend.

It helps plants grow,

keeps us warm,

and who doesn’t love to lie on the beach on a sunny day?

But for all of it’s good qualities,

the Sun can also be harmful in large amounts.

That’s why we invented sunscreen.

The purpose of sunscreen is to shield the body

from the Sun’s ultraviolet rays,

which have several harmful effects,

including sunburn,

aging,

and skin cancer promotion.

These rays are separated

by their different wave lengths,

into types such as UVA

and UVB,

which exert a variety of effects in the skin

due to the absorption patterns of chromophores,

the parts of the molecules

responsible for their color.

The primary two chromophores are hemoglobin,

found in our red blood cells,

and melanin, which gives our skin its pigment.

We know that UVB rays cause the skin to burn.

The role of UVA rays is less well understood

and appears to have an effect

on our tanning response,

carcinogenesis,

and aging.

So, how does the sunscreen protect us from these rays?

There are two basic types of sunscreen,

physical and chemical blockers.

Physical blockers, like zinc oxide

or titanium dioxide,

reflect the Sun’s rays by acting as a physical barrier.

If you’ve seen lifeguards with noses covered in white,

then you know what this looks like.

The same ingredients are primary components

of diaper creams,

where the goal is also to create a physical barrier.

Historically, they haven’t always been easy to apply

and were conspicuously visible on the skin,

but new formulations have made this less of an issue.

Chemical blockers, on the other hand,

absorb the Sun’s rays.

They deteriorate more quickly than physical sunscreens

because their ability to absorb the Sun diminishes.

Generally, these are more transparent

when rubbed on the skin,

but some people develop allergric reactions

to some of the chemicals.

Regardless of the type of sunscreen,

all are subjected to testing

to determine their sunburn protection factor,

or SPF.

This is essentially a measure of the protection

that the sunscreen will provide from UVB rays

before one begins to burn.

But even if you don’t burn,

you still need to use sunscreen

because unless you live in a cave,

you’re not immune to the effects of the Sun.

It is true that darker skinned people

and those who tan easily

have more built-in protection from sunburns,

but they are still vulnerable

to the effects of UVA.

Children under the age of six months,

on the other hand,

should have almost no sun exposure

as their protective mechanisms

are not fully functioning,

and their skin is more likely to absorb

any sunscreen that is applied.

Wearing sunscreen helps protect

against the development of all three types of skin cancer:

basal cell carcinoma,

squamous cell carcinoma,

and melanoma.

On a daily basis, the DNA in your cells

is developing mutations and errors

that are generally handled

by machinery within your cells,

but ultraviolet rays from the Sun lead to mutations

that the cell may not be able to overcome,

leading to uncontrolled growth

and eventual skin cancer.

The scariest thing about this

is that usually you can’t even see it happening

until its too late.

But if these concrete risks to your health

are not enough to convince you to use sunscreen,

there are aesthetic reasons as well.

Along with cigarette smoking,

sun damage is the leading cause of premature aging.

Photoaging from chronic sun exposure

leads to a loss of elasticity in the skin,

in other words, making it look saggy.

Take a look at this truck driver

who’s left side was chronically exposed to the sun

and notice the difference.

This is an important point.

Car windows block UVB, the burn rays,

but not UVA, the aging rays.

It is recommended to use sunscreen daily,

but you should pay special attention

before prolonged sun exposure

or when at the beach

or among snow

since the reflectivity of water and ice

amplifies the Sun’s rays.

For these cases, apply about an ounce

fifteen to thirty minutes before you go out

and once again soon after you get outside.

After that, you should reapply it every two to three hours,

especially after swimming or sweating.

Otherwise you should wear protective clothing

with ultraviolet protection factor, or UPF.

Stay in shaded areas,

such as under trees or an umbrella,

and avoid the sun at the peak hours

of 10 a.m. to 4 p.m.

And what’s the best kind of sunscreen?

Everyone will have their preference,

but look for the following things:

broad spectra,

SPF of at least 30,

and water-resistant.

A light moisturizer with SPF 30

should be good for daily use.

Take note if you decide to use a spray.

They take several coats to effectively cover your skin,

like painting a wall with a spray can

versus a paint brush.

So, enjoy the sun,

but enjoy it with sunscreen.

我们大多数人都认为太阳是我们的朋友。

它帮助植物生长,

让我们保持温暖

,谁不喜欢在阳光明媚的日子躺在沙滩上?

但是,尽管太阳具有所有优点,

但大量的太阳也可能有害。

这就是我们发明防晒霜的原因。

防晒霜的目的是保护身体

免受太阳紫外线的伤害,紫外线

会产生多种有害影响,

包括晒伤、

衰老

和促进皮肤癌。

这些射线

按其不同的波长

分为 UVA

和 UVB 等类型,

由于发色团的吸收模式(负责其颜色

的分子部分),

它们在皮肤中发挥各种作用。

主要的两种发色团是血红蛋白,

存在于我们的红细胞中,

而黑色素则赋予我们的皮肤色素。

我们知道 UVB 射线会导致皮肤灼伤。

UVA 射线的作用不太清楚

,似乎

对我们的晒黑反应、

致癌作用

和衰老有影响。

那么,防晒霜如何保护我们免受这些射线的伤害呢?

防晒霜有两种基本类型,

物理阻滞剂和化学阻滞剂。

物理阻挡剂,如氧化锌

或二氧化钛,

通过充当物理屏障来反射太阳光线。

如果你见过鼻子被白色覆盖的救生员,

那么你就知道这是什么样子了。

相同的成分

是尿布膏的主要成分,

其目标也是创造物理屏障。

从历史上看,它们并不总是很容易涂抹

并且在皮肤上很明显,

但是新的配方使这不再是一个问题。

另一方面,化学阻滞剂

吸收太阳光线。

它们比物理防晒霜退化得更快,

因为它们吸收阳光的能力减弱了。

一般来说,这些

在皮肤上摩擦时会更透明,

但有些人会对

某些化学物质产生过敏反应。

无论哪种类型的防晒霜,

都经过测试

以确定其防晒系数

或 SPF。

这本质上是衡量

防晒霜

在开始燃烧之前对 UVB 射线的保护程度。

但即使你不燃烧,

你仍然需要使用防晒霜,

因为除非你住在山洞里,否则

你无法免疫太阳的影响。

确实,深色皮肤的

人和容易晒黑的人

有更多的内在保护免受晒伤,

但他们仍然容易

受到 UVA 的影响。 另一方面,

6 个月以下的儿童

几乎不应该暴露在阳光下,

因为他们的保护

机制没有完全发挥作用,

而且他们的皮肤更容易吸收

任何涂抹的防晒霜。

涂抹防晒霜有助于

预防所有三种皮肤癌的发展:

基底细胞癌、

鳞状细胞癌

和黑色素瘤。

每天,您细胞中的 DNA 都在

发生突变和错误,这些突变和错误

通常

由细胞内的机器处理,

但来自太阳的紫外线会导致

细胞可能无法克服的突变,

从而导致不受控制的生长

并最终导致 皮肤癌。

最可怕的

是,通常你甚至无法看到它发生,

直到为时已晚。

但是,如果这些对您健康的具体风险

不足以说服您使用防晒霜,

那么也有审美原因。

与吸烟一起,

阳光伤害是过早衰老的主要原因。

长期暴露在阳光下的光老化

会导致皮肤失去弹性

,换句话说,使其看起来下垂。

看看

这位左侧长期暴露在阳光下的卡车司机

并注意其中的不同。

这是很重要的一点。

车窗可以阻挡 UVB(灼伤射线),

但不能阻挡 UVA(老化射线)。

建议每天使用防晒霜,

在长时间暴露在阳光下

或在海滩

或雪中时应特别注意,

因为水和冰的反射性会

放大太阳光线。

对于这些情况,

请在出门前十五到三十分钟涂抹约一盎司,

并在外出后不久再次涂抹。

之后,您应该每两到三个小时重新涂抹一次,

尤其是在游泳或出汗后。

否则,您应该穿

带有紫外线防护系数或 UPF 的防护服。

待在阴凉处,

如树下或雨伞下

,避免在

上午 10 点至下午 4 点的高峰时段晒太阳。

最好的防晒霜是什么?

每个人都有自己的喜好,

但要注意以下几点:

广谱、

SPF 至少 30

和防水。

SPF 30 的轻质保湿霜

应该适合日常使用。

如果您决定使用喷雾剂,请注意。

他们需要几层涂层才能有效地覆盖您的皮肤,

例如用喷雾罐

与油漆刷粉刷墙壁。

所以,享受阳光,

但享受防晒霜。