Why do we have to wear sunscreen?

The purpose of sunscreen is to shield the body from the sun's ultraviolet rays, which have many harmful effects. These rays are separated by their different wavelengths, into types such as UVA and UVB. 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 sunscreen protect us from these rays? There are two basic types of sunscreen: physical blockers and chemical blockers. Physical blockers 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. However, new formulations have made this less of an issue.

Sunscreen is important for stopping sunburn, but it's also effective against skin cancer. Depending on the type of sunscreen you use, it may also protect you from other types of cancer too. Most of these chemicals come in a liquid form and need to be rubbed into your skin before being absorbed. While it is true that darker-skinned people and those who tan easily tend to have more built-in protection from sunburns, they are still at risk for skin cancer no matter what. Children under the age of six months should have almost no sun exposure because their skin isn't yet fully developed and their cells can be more likely to absorb sunscreen.

The most terrifying part of this is that most of the time, you won't even notice it happening until it's too late. If these specific health dangers aren't enough to persuade you to use sunscreen, there are also aesthetic benefits. Sun damage is the main factor in early aging, along with cigarette smoking. Chronic sun exposure causes photoaging, which causes the skin to lose its suppleness and appear sagging. Observe the difference in this truck driver's left side, which was frequently exposed to the sun. This is a crucial point. Car windows block UVB, which causes burns, but not UVA, which causes aging.

Daily use of sunscreen is advised, but you should take extra precautions before prolonged exposure to the sun, when at the beach, or when in areas with snow, as the reflection of water and ice magnifies the sun's rays. For these situations, apply a small amount (15–30 minutes before leaving) and again right afterward after leaving the house. You should then reapply it every two to three hours, especially after swimming or perspiring. In any other case, you should wear protective clothes with a UPF rating for ultraviolet protection. Avoid the sun from 10 a.m. to 4 p.m. and stay in covered areas like those beneath trees or an umbrella.

And what is the best sunscreen? Everyone has a preference but check for the following features: broad spectral coverage, an SPF of at least 30, and water resistance. For daily use, a mild moisturizer with SPF 30 should be enough. Keep this in mind if you opt to use a spray. It takes multiple coats to cover your skin effectively, much like painting a wall with a spray can versus a paintbrush. So what do you think? Do we have to wear sunscreen?