Sunlight is essential for regulating our sleep patterns and producing vitamin D, which is vital for normal bone function and overall health. However, excessive exposure to sunlight can be harmful. Chronic exposure to ultraviolet (UV) radiation in sunlight is a known cause of nonmelanoma skin cancer. UV rays are classified into two types: UVA and UVB. UVB rays are shorter and can cause sunburn, while UVA rays are longer and can penetrate more deeply into the skin.
UVA rays contribute to skin aging and skin cancer, as they can pass through window glass and are emitted by lamps and tanning booths. A tan induced by UVA rays, such as from a tanning bed, provides 5-10 times less protection against subsequent UV exposure compared to a tan induced by UVB rays. This is because UVA-induced tans result in less noticeable thickening of the epidermis and hyperkeratosis, making the skin more susceptible to damage. UVA rays also suppress the immune system, affecting primary and memory T cell function, and are constant throughout the day and year. UVB rays, while also leading to skin aging and cancer, are more intense during summer, midday, at higher altitudes, and closer to the equator.
Skin cancer is the most common form of cancer in the U.S., with basal cell carcinoma (BCC) being the most prevalent type. BCC typically appears in sun-exposed areas like the face, scalp, ears, chest, back, and legs. These tumors often present as small, dome-shaped bumps with a pearly white color or as recurring sores that bleed, heal, and reappear. An estimated 3.6 million cases of BCC are diagnosed annually in the U.S. More people are diagnosed with skin cancer each year in the U.S. than all other cancers combined, with 1 in 5 Americans developing skin cancer by age 70. The U.S. experiences over two skin cancer-related deaths every hour, and having five or more sunburns doubles the risk of developing melanoma. If melanoma is detected early, the five-year survival rate is as high as 99%.
The International Agency for Research on Cancer, part of the World Health Organization, classifies UV tanning devices as Group 1 carcinogens, a category that also includes plutonium, cigarettes, and solar UV radiation. Risk factors for skin cancer, aside from chronic UV exposure, include light complexion, light eyes, blonde or red hair, freckles, poor tanning ability, easy sunburning, numerous moles, genetics, and history of blistering sunburns.
Preventing skin cancer involves protecting oneself from UV rays by avoiding tanning beds and using sunscreen or protective clothing. Sunscreen contains Sun Protection Factor (SPF), with broad-spectrum SPF covering both UVA and UVB rays. There are two main types of sunscreens: chemical and mineral (or physical). Both are effective and available over the counter. Mineral sunscreens, containing zinc oxide or titanium dioxide, reflect and scatter harmful rays and are usually thick and white, requiring time to rub into the skin. They should be applied at least 15 minutes before sun exposure and are preferred for lighter skin and drier skin types.
Chemical sunscreens also protect against UVA and UVB rays, but some formulations may not fully cover UVA rays. Active ingredients include avobenzone, octinoxate, and oxybenzone. These sunscreens absorb into the skin, where they convert UV rays into heat and release them from the body. Chemical sunscreens do not need to be applied 15 minutes before sun exposure, as they work upon direct contact with the skin. They tend to apply more evenly, do not leave a white cast, and are often more sweat-resistant than mineral sunscreens.
Hung M, Beazer IR, Su S, Bounsanga J, Hon ES, Lipsky MS. An Exploration of the Use and Impact of Preventive Measures on Skin Cancer. Healthcare (Basel). 2022 Apr 15;10(4):743. doi: 10.3390/healthcare10040743. PMID: 35455920; PMCID: PMC9025621.
Sander, Megan et al. “The efficacy and safety of sunscreen use for the prevention of skin cancer.” CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne vol. 192,50 (2020): E1802-E1808. doi:10.1503/cmaj.201085
Sunlight is essential for regulating our sleep patterns and producing vitamin D, which is vital for normal bone function and overall health. However, excessive exposure to sunlight can be harmful. Chronic exposure to ultraviolet (UV) radiation in sunlight is a known cause of nonmelanoma skin cancer. UV rays are classified into two types: UVA and UVB. UVB rays are shorter and can cause sunburn, while UVA rays are longer and can penetrate more deeply into the skin.
UVA rays contribute to skin aging and skin cancer, as they can pass through window glass and are emitted by lamps and tanning booths. A tan induced by UVA rays, such as from a tanning bed, provides 5-10 times less protection against subsequent UV exposure compared to a tan induced by UVB rays. This is because UVA-induced tans result in less noticeable thickening of the epidermis and hyperkeratosis, making the skin more susceptible to damage. UVA rays also suppress the immune system, affecting primary and memory T cell function, and are constant throughout the day and year. UVB rays, while also leading to skin aging and cancer, are more intense during summer, midday, at higher altitudes, and closer to the equator.
Skin cancer is the most common form of cancer in the U.S., with basal cell carcinoma (BCC) being the most prevalent type. BCC typically appears in sun-exposed areas like the face, scalp, ears, chest, back, and legs. These tumors often present as small, dome-shaped bumps with a pearly white color or as recurring sores that bleed, heal, and reappear. An estimated 3.6 million cases of BCC are diagnosed annually in the U.S. More people are diagnosed with skin cancer each year in the U.S. than all other cancers combined, with 1 in 5 Americans developing skin cancer by age 70. The U.S. experiences over two skin cancer-related deaths every hour, and having five or more sunburns doubles the risk of developing melanoma. If melanoma is detected early, the five-year survival rate is as high as 99%.
The International Agency for Research on Cancer, part of the World Health Organization, classifies UV tanning devices as Group 1 carcinogens, a category that also includes plutonium, cigarettes, and solar UV radiation. Risk factors for skin cancer, aside from chronic UV exposure, include light complexion, light eyes, blonde or red hair, freckles, poor tanning ability, easy sunburning, numerous moles, genetics, and history of blistering sunburns.
Preventing skin cancer involves protecting oneself from UV rays by avoiding tanning beds and using sunscreen or protective clothing. Sunscreen contains Sun Protection Factor (SPF), with broad-spectrum SPF covering both UVA and UVB rays. There are two main types of sunscreens: chemical and mineral (or physical). Both are effective and available over the counter. Mineral sunscreens, containing zinc oxide or titanium dioxide, reflect and scatter harmful rays and are usually thick and white, requiring time to rub into the skin. They should be applied at least 15 minutes before sun exposure and are preferred for lighter skin and drier skin types.
Chemical sunscreens also protect against UVA and UVB rays, but some formulations may not fully cover UVA rays. Active ingredients include avobenzone, octinoxate, and oxybenzone. These sunscreens absorb into the skin, where they convert UV rays into heat and release them from the body. Chemical sunscreens do not need to be applied 15 minutes before sun exposure, as they work upon direct contact with the skin. They tend to apply more evenly, do not leave a white cast, and are often more sweat-resistant than mineral sunscreens.
Hung M, Beazer IR, Su S, Bounsanga J, Hon ES, Lipsky MS. An Exploration of the Use and Impact of Preventive Measures on Skin Cancer. Healthcare (Basel). 2022 Apr 15;10(4):743. doi: 10.3390/healthcare10040743. PMID: 35455920; PMCID: PMC9025621.
Sander, Megan et al. “The efficacy and safety of sunscreen use for the prevention of skin cancer.” CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne vol. 192,50 (2020): E1802-E1808. doi:10.1503/cmaj.201085