Final answer:
Melanocytes are the primary cells involved in the tanning process, producing melanin in response to UV-B radiation which helps protect DNA from damage. This process peaks in about 10 days, but the resulting tan is impermanent as the skin naturally sheds melanin over time. Prolonged exposure to UV, even in tanning salons, may still pose a risk of cell damage and skin cancer.
Step-by-step explanation:
The cell type primarily involved in the tanning process is the melanocyte. Melanocytes are located in the stratum basale layer of the epidermis and produce melanosomes containing melanin. The UV-B radiation from the sun or tanning salons stimulates these melanocytes to increase melanin production, which then is transferred to keratinocytes in the upper layers of the skin to absorb UV light, protecting the DNA from potential damage that could lead to mutations or skin cancer.
It takes about 10 days after initial sun exposure for melanin synthesis to peak, culminating in a darker skin tone known as a tan. The process is, however, not permanent because melanosomes are eventually broken down and melanin-filled keratinocytes are shed from the skin's surface. Lastly, while tanning salons claim to use "safe" UV light, prolonged exposure can still potentially cause cell damage and induce cancer.