tanning

Tanning is the change of skin color in response to ultraviolet (UV) radiation from the sun or artificial sources. The tan results from increased production and distribution of melanin, the pigment produced by melanocytes in the epidermis, which absorbs UV radiation and helps protect skin from further damage. Melanin is then transferred to keratinocytes, causing visible darkening of the skin.

Tanning occurs primarily outdoors through sun exposure; UVB rays drive new melanin production, while UVA rays contribute to immediate darkening and aging. Indoor tanning uses UV-emitting lamps that deliver UVA and UVB, often producing faster results but with similar health risks. Sunless or cosmetic tanning products, such as DHA-based lotions or sprays, color the skin surface without UV exposure but do not provide UV protection.

Health effects: Short-term risks include sunburn and pigment changes; long-term risks include photoaging and higher likelihood of skin cancers (basal cell, squamous cell, melanoma), especially with repeated or intense exposure. People with fair skin, red or blond hair, or a history of sunburns are at higher risk. UV exposure can also damage eyes and affect immune function.

Prevention and policy: Many health authorities discourage tanning, particularly in indoor facilities. To reduce risk, use broad-spectrum sunscreen with SPF 30 or higher, reapply as directed, wear protective clothing and hats, and seek shade during peak sun hours. Avoid tanning beds, especially for minors where prohibited. For color without UV exposure, sunless tans are an alternative, though they do not provide UVA/UVB protection.

Terminology: Tanning includes an immediate tanning response (oxidation of existing melanin) and a delayed response (new melanin synthesis within days). The term can refer to the process or the resulting pigmentation.