Continuing with our medical monthly highlight series, we take a look at the history of ultraviolet photobiology and its studies over the years. Specifically, we’re learning how it impacts the human body. Let’s dive in!
Background
Ultraviolet (UV) radiation was first brought to light by Becquerel and Draper in 1842. They each proved that when sunlight passes through a prism on to a surface with silver iodide, wavelengths that were between 340 and 400 nanometers produced a photochemical reaction. It wasn’t until the 20th century, however, that the relationship between UV radiation from the sun and skin changes became apparent (Hockberger, 2007).
For centuries the sun light was used as a healing treatment for ailments such as smallpox, rickets, acne vulgaris, or seasonal affective disorder. In the 19th century it was shown that UV rays were harmful to the human body through the use of arc lamps. Those studying them would sustain eye problems and skin burns from the UV rays emitted. It was further shown that the UV radiation (chemical rays) caused the skin to appear red hours after exposure, loss of skin (peeling or blistering), and eventually increased pigmentation (tan). Skin exposed to sunlight often was also thicker and showed increased keratinization (Hockberger, 2007).
Despite the fact that approximately 40% of the UV radiation from the sun is filtered through the ozone layer, what does pass through the the surface of the planet cause changes in the skin cells (Hockberger, 2007). When the melanocytes in the skin become exposed to UV rays they migrate to the surface and begin to mutate becoming melanoma, the most dangerous of the three types of skin cancer. Extensive exposure to UV rays can also cause mutations in basal cells and squamous cells leading to carcinoma (The Skin Cancer Foundation, 2019).
In next week’s segment we’ll explore the three types of skin cancer and what symptoms to watch out for. Have a great week!
References
Hockberger, P. E. (2007). A history of ultraviolet photobiology for humans, animals, and microorganisms. Photochemistry and Photobiology, 76(6), 561-579.
The Skin Cancer Foundation. (2019). UV radiation and your skin. Retrieved from https://www.skincancer.org/risk-factors/uv-radiation/
