Ultraviolet Radiation (UVR)
Ultraviolet Radiation (UVR) is a type of electromagnetic radiation that comes primarily from the sun, but can also be emitted by artificial sources like tanning beds and welding equipment. Although invisible to the naked eye, UVR has significant biological effects on the skin. It plays a major role in photoaging, DNA damage, and skin cancers. UVR is divided into three types: UVA, UVB, and UVC, based on wavelength.
While UVC is mostly absorbed by the Earth’s atmosphere and doesn’t reach the surface, UVA and UVB rays do penetrate the atmosphere and the skin, with differing levels of energy and depth of penetration.
Types of UV Radiation
- UVA (320–400 nm): Accounts for about 95% of the UV radiation reaching the Earth’s surface. Penetrates deeply into the dermis and contributes to premature skin aging, wrinkles, and long-term skin damage. It also plays a role in some skin cancers.
- UVB (280–320 nm): Has more energy than UVA and primarily affects the epidermis. Responsible for sunburns, tanning, and direct DNA damage that can lead to skin cancers.
- UVC (100–280 nm): The most energetic and potentially harmful form of UV, but it is completely absorbed by the ozone layer and does not reach the Earth’s surface.
Effects on the Skin
- Causes DNA damage in skin cells, which can lead to mutations and increase the risk of skin cancer.
- Triggers inflammation and sunburn (primarily from UVB exposure).
- Accelerates photoaging by breaking down collagen and elastin fibers in the dermis (mainly from UVA exposure).
- Leads to pigmentation disorders such as melasma, sunspots, and uneven skin tone.
- Weakens the skin’s immune response, making it less capable of fighting infections and repairing damage.
Health Risks
- Prolonged or unprotected exposure significantly increases the risk of skin cancers, including basal cell carcinoma, squamous cell carcinoma, and malignant melanoma.
- Associated with eye damage, including cataracts and photokeratitis (sunburn of the eye).
- Recognised by the World Health Organization (WHO) as a Group 1 carcinogen (proven to cause cancer in humans).
Protection & Prevention
- Use a broad-spectrum sunscreen with SPF 30 or higher daily, even on cloudy days or when indoors near windows.
- Wear protective clothing, wide-brimmed hats, and UV-blocking sunglasses.
- Seek shade during peak UV hours (10 AM to 4 PM).
- Avoid tanning beds and artificial UV sources.
- Use UV-protective films or shades on windows to reduce indoor exposure.
- Store skincare products in cool, dark places to prevent UV degradation of ingredients.