Preventing Skin Cancer: Why Is Wearing Sunscreen So Important?


There are several dangers of not wearing sunscreen. This guide further explains why you should protect yourself from the sun each time you go out.

There are about 150,000 new cases of skin cancer across the globe every year. The incidence could be much higher though since non-melanoma cases are often underdiagnosed and underreported in many parts of the world.

Skin cancer is a serious condition. The good news is that, since sun exposure is one of the main causes of skin cancer, it is preventable. One of the best methods of prevention is very affordable and easy: wearing sunscreen.

This article covers everything you need to know about preventing skin cancer by applying sunscreen. It covers the different types and the best sunscreen for different situations. Keep reading to find out how you can keep your skin healthy and cancer-free.

How Radiation Causes Cancer

Radiation is the emission of energy from a source. High-energy radiation comes from things like X-rays. Radio waves are a common source of low-energy radiation.

Ultraviolet (UV) radiation is middle-spectrum energy. It comes from various man-made sources, such as tanning beds and tools like welding torches, as well as the sun.

The way radiation (not just UV rays) can cause cancer is its ionizing capacity. This means they have enough energy to force an electron (ionize) from atoms. This can damage human DNA cells, or genes, which can lead to the formation of cancer.

High-frequency radiation like X-rays can penetrate deep into the body and cause cancer internally. UV rays are not that strong, but they can have the same effect on skin cells.

Most skin cancers result from exposure to UV rays from sunlight. We know this because, both basal cell and squamous cell cancers––the two most common types of skin cancer––are most often found on parts of the body that see a lot of sun exposure.

Types of UV Rays

There are three main types of UV radiation. UVA rays have the least energy and are mostly linked to premature aging and wrinkles. Yet they can still play an indirect role in damaging skin cells’ DNA, which can lead to cancer. 

UVB rays have a bit more energy than UVA rays. They are the main rays responsible for sunburns and do have the ability to damage DNA in skin cells directly. They are the main culprits of skin cancer caused by the sun.

UVC rays have the most energy of all UV rays. While they come from man-made sources of UV light, such as welding equipment or mercury lamps, UVC from the sun rarely reaches Earth. That is because it reacts with ozone in the atmosphere and dissipates.

For this reason, UVVC is not thought to be a major cancer-causing agent in sun rays. Approximately 95 percent of the sun rays that reach the ground are UVA, and the other 5 percent are UVB. When you hear “broad spectrum” sunscreen, this is a product that can block both types of radiation.

Contributing Factors That Impact UV Exposure

Some factors make you more at risk of UV exposure, and make taking precautions like wearing sunscreen all the more vital. One is the time of day that you are out in the sun. During the middle part of the day, when the sun is overhead, you have more direct exposure to emanating rays.

Your latitude on the planet is also a factor. The closer you are to the equator the more intense the sun's rays. Likewise, higher altitudes see stronger UV rays than lower ones.

Many people assume they can go outside on cloudy days and not get sunburned. While the presence of clouds can block some UV rays, many still get through. Even on extremely overcast days, you are not completely shielded from the sun’s harmful rays.

Types of Sunscreen

A good way to understand how sunscreen works is through an examination of the different available types. This also will give you a better idea of which products are best for different situations.

Chemical Sunscreens

The most common type of sunscreen available is chemical sunscreens. These use different components--like avobenzone, octinoxate, and oxybenzone--that are good at absorbing UV rays and converting them to heat.

Two advantages of chemical sunscreens are that you can buy them almost anywhere, and they are often inexpensive. Keep in mind though that not all are the same. Cheaper chemical sunscreens can leave a greasy, sticky feel to the skin.

Quality chemical sunscreens will go on smoothly and produce a thorough coat on your skin. This ease of application (and reapplication, which we will see in a moment is very important) can make them more effective at ensuring your skin is protected.

Mineral Sunscreens

Mineral sunscreens work differently than chemical ones. They are also known as “physical” sunscreens because, rather than absorbing UV rays, they create a physical barrier on the skin. This deflects harmful rays, protecting the skin underneath.

The most common types of mineral sunscreen have either zinc oxide or titanium dioxide (or a combination of each). Both of these substances are completely safe to have in contact with the skin.

One of the biggest advantages of mineral sunscreens is that they are free from chemicals that can irritate the skin. People with sensitive skin, as well as those who have concerns about potential health risks associated with certain chemicals, prefer mineral sunscreens as an alternative.

One downside to mineral sunscreens is that they have a thicker consistency and can be difficult to spread. They are also more likely than some chemical sunscreens to leave behind a white coat on the skin. Yet, when applied correctly, they can be more effective at blocking most of the sun’s rays.

Lotions vs. Spray Sunscreens

Lotions are the most common type of sunscreen. Spray sunscreens are ideal for a quick and easy application.

Most chemical ones produce a clear coat, so you do not have to worry about a chalky white coat. You must be certain that you spray a generous amount to ensure enough of the solution is protecting your skin. Mineral sunscreens generally come as a lotion, although there are a handful of sprays out there (though they still tend to go on thick).

Water-Resistant Sunscreens

Since swimming is a common activity that exposes the skin to sun rays, water-resistant sunscreen has become a popular option. This also makes them ideal for sports, since they can provide the same resilience against sweat.

Unlike standard sunscreens that water or sweat can wash away, water-resistant sunscreens cling to the skin and last much longer. You still must regularly reapply them to provide adequate protection.

What Is SPF?

“SPF” stands for “sun protection factor.” It is a rating that has to do with the duration from when you apply it.

For instance, SPF 15 is meant to protect you 15 times longer than if you were in the sun without any sunscreen at all. SPF 30 should protect you twice as long as SPF 15.

The problem is that none of these numbers explain how long you have protection in real-world circumstances. As mentioned, water and sweat can dissipate sunscreen. If you are closer to the equator then the sunscreen is working much harder to absorb or deflect rays, and will wear out faster.

Regardless of the conditions, you can expect any level of SPF sunscreen to dissipate pretty quickly after application. No matter the strength, you should always reapply sunscreen every two hours, or even more frequently, to guarantee protection.

There has been much confusion about whether SPF relates to time or level of protection. In fact, it is both. 

SPF 15 will block about 93 percent of UV rays, while SPF 30 gets you up to about 30 percent (this is why many health professionals recommend at least SPF 30). SPF only goes a bit further to 98 percent, and SPF 100 blocks 99 percent of all UV rays.

The takeaway is that you get longer and better protection from higher SPF ratings, but you still need to reapply them on a regular basis. In fact, you would be better off using a lower SPF that you reapply often than an SPF 100 that you put on and assume you are protected all day.

What Is PA+?

A second rating you will find on sunscreens is a “PA” with between one and four plus signs behind it. PA stands for “Protection Grade of UVA.” As the name suggests, this is a rating system for the level of protection a sunblock provides against only UVA rays.

This rating is useful since SPF protection is related to UVB rays. Unlike SPF though, the number of plus signs in the PA rating does not mean you get that much more multiples of protection. PA+++ simply provides more protection than PA++, which is stronger than PA+.

Learn More About How Wearing Sunscreen Prevents Skin Cancer

Now that you understand how wearing sunscreen can help guard against sun damage, including cancer, you can take steps to protect yourself and your family. With such an assortment of sunblock products available, you are sure to find one that fits your health goals and lifestyle.

At Minou and Lily, we provide quality skincare products, including a variety of sunscreens. We carry a large assortment of name-brand products at competitive prices. Take a look at our extensive online inventory or reach out to us today to learn more about our products.