May is skin cancer awareness month. It is also the start of warmer weather and sunnier days. This is the second blog post about sun and skin safety.
What is UV radiation? Why do we need to worry about it and protect against it? I have a base tan, why do I need sunscreen? Which SPF sunscreen should I use?
What is UV radiation?
Ultraviolet (UV) radiation is a type of electromagnetic radiation produced by the sun (and some man made sources like tanning beds). There are 3 types: UVA, UVB, and UVC. The differences between them have to do with wavelength. UVC is the strongest (shortest wavelength), but is absorbed in the earth's ozone layer. UVB light has a medium wavelength and is the stronger of the two types that affect humans. It has a negative impact on your skin cells, and the DNA within them, having a direct link with skin cancers. UVA radiation has the longest wavelength, and is the weakest. It is a stronger contributor to longterm skin damage (wrinkles, leathery skin, etc.) than skin cancer. The term broad spectrum refers to UVR that includes both UVA and UVB.
Why do we need to protect against UV radiation?
According to the ultraviolet-radiation-related exposures in the Report on Carcinogens (1), broad spectrum UVR causes DNA damage, suppression of the immune system, tumor promotion, and mutations in the p53 tumor-suppressor gene leading to skin cancer. Overall, the final result depends on the type of UVR and the ability of our bodies to repair the damaged cells. In cases where skin cancer resulted, the p53 tumor-suppressor gene mutation was present in 90% of human squamous-cell carcinomas. Even more importantly, this gene mutation was found in 74% of sun-exposed skin and 5% of unexposed skin. This indicates the importance sun exposure has on risk of developing skin cancers.
I have a base tan, why do I need sunscreen?
Sunburns are a physiological response to damaged skin cells. Not only are skin cancers more commonly found on areas on the body that have had previous sun exposure, but having had serious sunburns in the past increases your risk of developing these cancers (more sunburns associated with higher risk). Melanin production is also a result of sun exposure. Althougth melanin may help to reflect UVR with a sun protective factor (SPF) of 2-4 (2) during future sun exposure, it was not able to protect your cells during the event that caused the resultant increase in melanin.
Sun Safety Tip #3
Avoid burning. This increases your risk of developing skin cancer (see above).
Sun Safety Tip #4 - Which SPF sunscreen should I use?
Sunbath - by Lisa Widerberg - CC BY
Avoid Sunburn - by Juhan Sonin - CC BY
Dr. Judith McCann has been living in York Region for over 15 years. After going to Queen's University in Kingston for Kinesiology, and Canadian Memorial Chiropractic College in Toronto to become a chiropractor, she decided to move back and open Haptic Health and Chiropractic in Newmarket. In February 2017, Haptic Health and Chiropractic moved 10 minutes up the road to Sharon in East Gwillimbury.