SILVER SPRING, MD – July 3, 2024 – Sunscreen and sunblock products are recommended by doctors to reduce the risk of getting skin cancer. Sunscreen and sunblock can protect people from the sun’s harmful ultraviolet (UV) rays, but in different ways. Sunscreen products contain chemicals that can absorb the UV rays (deactivating the rays) before they can affect the skin. While sunblock (which is oftentimes referred to as a sunscreen too) contains the minerals zinc oxide or titanium oxide. These chemicals act as a physical barrier that reflect the sun’s rays before they reach the skin. Sunblock can also protect against sunburn and ‘sun poisoning,’ a more severe form of sunburn.
Here are some differences between sunscreen and sunblock. Sunscreen is easy to rub into your skin and it disappears completely. It should be applied 20 minutes before exposure to the sun to be fully absorbed. Some people with sensitive skin may develop contact dermatitis so people with sensitive skin should use sunblock. Sunblock is slathered onto the skin. It sits on top of the skin and works immediately. Some sunblock products leave a white residue on the skin. However, newer sunblock products, made with mineral nanoparticles, can be rubbed into the skin and do not leave the white residue.
Ultraviolet light can cause skin cancer, cataracts of the eye, damage to the skin called sunburn, and premature aging of the skin. UV light is comprised of A waves and B waves. Both are harmful to your skin. Overexposure to B waves can cause sunburn, while A waves can cause sunburn and skin cancer. UV light can damage DNA in skin cells causing genetic mutations which can initiate cancers to grow. Skin cancer is the most common cancer in the U.S. Most UV-caused skin cancer occur on sun-exposed areas of the skin. Skin cancer can be prevented by using sunscreen and sunblock and taking other precautions. Basal cell and squamous cell carcinomas, the most common skin cancers, are usually curable with early diagnosis and treatment. Melanoma is less frequent and the most-deadly form of skin cancer.
The American Academy of Dermatology recommends a sunscreen or a sunblock that has a rating of SPF 30 or higher. It should be water resistant. Choose a broad-spectrum product to protect against UVA & UVB waves. Apply sunscreen to exposed skin 20 minutes before going outside throughout the year. Clouds do not adequately block UV rays, so use skin protectants even on cloudy days. An adult should apply about 1 ounce of sunscreen, about the size of a shot glass, especially over the face, chest, and shoulders. Reapply every 2 hours or more frequently after swimming or sweating. Other measures include wearing long-sleeved clothing, a broad-brimmed hat, and sunglasses.
Sunscreen and sunblock products may contain ingredients that are harmful to people and the environment. The U.S. Food and Drug Administration (FDA) evaluates these products to ensure that they meet safety and effectiveness standards before each product is allowed to be used by Americans. According to a 2020 study by the FDA and published in the Journal of the American Medical Association, some of the active ingredients can be absorbed into the skin and enter the body. Recently the FDA has recalled some products that were found to be contaminated with benzene, a known carcinogen. According to Save the Reef, an organization dedicated to saving the world’s ocean and marine life, some popular chemicals found in sunscreen have been found to be toxic to coral reefs as are nanoparticles in some newer sunblock products. A list of these substances can be found at: https://savethereef.org/about-reef-save-sunscreen.html
Listen to the full report below:
Contact: Dr. Dick Needleman, Health reporter, 103.3 AshevilleFM, healthyasheville@ashevillefm.org