Screening Out the Sun: The Importance of Sunscreen


Although for some, sunscreen has become synonymous with summertime and those nostalgic beach and lake days, sunscreen’s influential function should be continuously embraced, regardless of the season. From the surface level, sunscreen helps avoid sunburns, but from a molecular perspective, sunscreen’s complexities lead it to fall into two categories: chemical (also referred to as organic) and physical (also referred to as inorganic). Chemical blockers function to absorb the sun’s rays like a sponge, and it includes active ingredients such as oxybenzone, avobenzone, homosalate, and octinoxate. On the other hand, physical sunscreen works to reflect the harmful UV radiation away from the individual’s skin and will include zinc oxide and/or titanium dioxide in its active ingredient list; this physical protection is most suitable for sensitive skin types as it lacks the potential multitude of active ingredients found in chemical sunscreen. 




Sun Rays:

The sun emits two kinds of rays: UVA and UVB radiation. UVB rays produce visible sunburns and negatively impact the skin’s surface which oftentimes leads to some variety of skin cancers while UVA light targets deeper skin tissue, causing premature aging and wrinkle formation. It is important for sunscreen to combat both forms of radiation to optimize its defensive function. In response to the variety of damaging sun rays, the most protective form of sunblock possesses characteristics that will defend against both UVA and UVB radiation, known as broad spectrum protection.


Benefits from sunscreen: 

  • decreases risk of developing skin cancer
  • evens complexion
  • protects against signs of premature aging
  • limits appearance of sunspots
  • avoids broken blood vessels


Diseases from sun damage: 

Skin Cancer- most common and preventable form of cancer

  • Basal Cell Carcinoma- curable with proper treatment, does not metastasize
  • Malignant melanoma- “black mole” skin cancer, can spread quickly and can cause death if not quickly treated

Photoaging- premature wrinkles, loose/irregular skin, skin color changes

Actinic keratosis- rough, sandpaper-like, scaly skin spots that oftentimes leads to skin cancer

Telangiectasia- a condition which thins the walls of blood vessels


Sunscreen Awareness at THS:


In response to a sunscreen poll distributed to THS students, many responded that they avoid wearing sunscreen due to Washington’s thematically cloudy environment, especially in the winter months. Regardless of the time of year or temperature, UV radiation can strike and negatively affect skin health. As the winter season has officially arrived, it is critical to stay aware of the sun’s continuous influence. While clouds do reduce some of the sun’s rays, UVA lights can penetrate clouds and reach below water’s surface; when in water, be sure to use waterproof sunscreen. Also, UVA can cause sunburns through windows, underlining the extensive reach of the sun and importance of wearing sunscreen inside and outside. 


Sun Safety:

The sun’s powerful UV rays can detrimentally impact skin in as little as fifteen minutes, emphasizing the importance of applying sunscreen regularly. To avoid these potential effects, it is imperative for individuals to consider the following safety tips:

  • Avoid sun exposure between 10am and 4pm when the sun’s rays are strongest
  • Reapply sunscreen about every two hours
    • Over time, the sun breaks down sunscreen’s active ingredients, and physical activity can wipe off sunscreen; so, reapplication is key.
  • Check expiration dates- like food, sunscreen can spoil and go bad, and expired sunscreen is often watery and does not effectively act to absorb, reflect, or scatter UV light
  • Avoid sun tanning and tanning beds — both natural and artificial UV light exposure are harmful
  • Full coverage clothing– tightly woven fabrics offer best protection, but clothing oftentimes only provide SPF of about 15


When looking to buy sunscreen, keep an eye out for sunscreen that is broad-spectrum and water-resistant with an SPF of at least 30 to ensure a sophisticated level of protection from radiation. Although sunscreen plays a pivotal role in protecting users’ skin from harmful UV rays from the sun, limiting sun exposure is the most effective way to ensure sun safety. 


“Is Sunscreen Safe?” American Academy of Dermatology,

Publishing, Harvard Health. “The Science of Sunscreen.” Harvard Health,

“Sunburn.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 17 July 2020,,gives%20skin%20its%20normal%20color.

Waxman, Eliana. “Feel the Burn? Explaining the Science of Sunscreen.” UChicago Medicine, UChicago Medicine, 18 July 2018,,reflect%20and%20scatter%20UV%20radiation.

“What Is the Difference between UVA and UVB Rays?” University of Iowa Hospitals & Clinics, 9 Oct. 2018,,are%20responsible%20for%20producing%20sunburn.&text=In%20addition%2C%20the%20UVA%20rays,including%20wrinkle%20formation%20(photoaging).